title: Moe Howard

text: On November 22, 1955, Shemp died of a heart attack at age 60, necessitating another Stooge. Producer Jules White used old footage of Shemp to complete four more films, with Columbia regular Joe Palma filling in for Shemp (thus creating the Fake Shemp phenomenon), until Columbia head Harry Cohn hired Joe Besser in 1956. According to Moe's autobiography, Howard wanted a "two-stooge" act, and Cohn's idea, not Howard's, was to replace Shemp as part of the act.


title: Moe Howard

text: The Stooges replaced Shemp with Besser; already an established Columbia comedy shorts star in his own right and frequent movie supporting player. Joe, Larry, and Moe filmed 16 shorts through December 1957. Shortly before Cohn's death in February 1958, the making of short subjects ended. Keeping himself busy, Moe was hired by Harry Romm as associate producer. According to Moe, stories (and later, scenes in a 2000 made-for-TV biopic) that he was forced to take a job as a gofer at Columbia are entirely false.


title: Moe Howard

text: Columbia sold the Three Stooges' library of short films to television under the Screen Gems name. With this, the Three Stooges quickly gained a new audience of young fans. Ever the businessman, Moe Howard put together a new Stooges act, with burlesque and screen comic Joe DeRita (dubbed "Curly-Joe" because of his vague resemblance to Moe's late younger brother Curly Howard and to differentiate him from Joe Besser) as the new "third Stooge". DeRita, like Shemp Howard and Joe Besser, had starred in a series of his comedy shorts. Several local television children's shows around the country began running the Stooges films, among them Paul Shannon, host of Adventure Time at WTAE-TV in Pittsburgh and Sally Starr at WFIL in Philadelphia. The films were so popular some young fans tried to emulate Moe's slapping, gouging, and hitting, prompting the Stooges to warn them against trying to re-create those actions.


title: Moe Howard

text: The revitalized trio starred in six feature-length movies: "Have Rocket, Will Travel" (1959); "Snow White and the Three Stooges" (1961), "The Three Stooges Meet Hercules" and "The Three Stooges in Orbit" (1962), "The Three Stooges Go Around the World in a Daze" (1963), and "The Outlaws Is Coming" (1965).


title: Moe Howard

text: Howard, Larry, and Curly-Joe continued to make live appearances, many notable "guest appearances", particularly in "It's a Mad, Mad, Mad, Mad World" (1963) as three firemen who appear for only a few seconds, and a longer appearance in "4 for Texas" (also 1963) starring Frank Sinatra and Dean Martin. The men tried their hand at a children's cartoon show titled "The New Three Stooges", with the cartoons sandwiched between live-action segments of the Stooges filmed in color.


title: Moe Howard

text: During this period, Moe and the Stooges appeared on numerous television shows, including "The Steve Allen Show", "Here's Hollywood", "Masquerade Party", "The Ed Sullivan Show", "Danny Thomas Meets The Comics", "The Joey Bishop Show", "Off To See The Wizard", and "Truth or Consequences" but, by the late 1960s, they were all at an age where they could no longer risk serious injury while performing slapstick comedy.


title: Moe Howard

text: The men were paid residuals for their later efforts and continued to receive the bulk of the profits from sales of Stooges merchandise. Moe sold real estate when his show-business life slowed down. However, he still did minor solo roles and walk-on bits in movies, such as "Don't Worry, We'll Think of a Title" (1966) and "Doctor Death: Seeker of Souls" (1973), as well as several appearances on "The Mike Douglas Show" in the 1970s.


title: Moe Howard

text: In one of Douglas' episodes, Moe, his hair in a style popular at the time, made a surprise appearance during an interview with the writer of a "where-are-they-now" book. When the audience was given a chance to ask the writer about famous people, Howard asked, "Whatever happened to the Three Stooges?" Finally recognized by Douglas, he combed his hair into his trademark style.


title: Moe Howard

text: The Stooges attempted to make a final film in 1969, "Kook's Tour", which was essentially a documentary of Howard, Larry, and Curly Joe out of character, touring the US, and meeting with fans. Still, production abruptly halted when on January 9, 1970, Larry suffered a major stroke during filming, paralyzing the left side of his body. He died on January 24, 1975, at age 72. Enough footage of Larry was shot so that "Kook's Tour" was eventually released in a 52-minute version to home video. After Fine's stroke, Howard asked longtime Three Stooges supporting actor Emil Sitka to replace Larry, but this final lineup never shot any material.


title: Moe Howard

text: On June 7, 1925, Moe Howard married Helen Schonberger, a cousin of Harry Houdini. The following year, Schonberger persuaded Howard to retire since she was pregnant. Howard attempted to earn a living in a succession of "normal" jobs, none of which was very successful, and he soon returned to working with Ted Healy.


title: Moe Howard

text: Howard and Schonberger had two children, Joan Howard (April 2, 1927 – September 21, 2021) and Paul Howard (born July 8, 1935).


title: Moe Howard

text: Howard died of lung cancer at age 77 on May 4, 1975, at Cedars-Sinai Medical Center in Los Angeles, where he had been admitted a week earlier in April, just over three months after Larry Fine's death, and more than a month before his 78th birthday. He was a heavy smoker for much of his adult life. He was interred in an outdoor crypt at Culver City's Hillside Memorial Park Cemetery. His wife Helen Schonberger died of a heart attack on October 31, 1975, at age 75 and was interred in the crypt next to him on the right. At the time of his death, Howard was working on his autobiography titled "I Stooged to Conquer". It was released in 1977 as "Moe Howard and the Three Stooges".


title: Moe Howard

text: Howard and the Three Stooges received a posthumous star on the Hollywood Walk of Fame on August 30, 1983, at 1560 Vine Street.


title: Moe Howard

text: Howard was portrayed by Paul Ben-Victor in "The Three Stooges", a 2000 made-for-TV biopic that focused on the trio's years in show business and their off-screen lives. In the 2012 Farrelly brothers' film "The Three Stooges", Chris Diamantopoulos portrays Howard. Skyler Gisondo portrays Young Howard.


title: Tony Romo

text: Antonio Ramiro Romo (born April 21, 1980) is an American sportscaster and former American football quarterback who played in the National Football League (NFL) for 14 seasons with the Dallas Cowboys. He played college football at Eastern Illinois, where he made an Ohio Valley Conference championship appearance in 2001 and won the Walter Payton Award the following year. Romo signed with the Cowboys as an undrafted free agent in 2003.


title: Tony Romo

text: Beginning his career in a backup role, Romo served as the Cowboys' primary starter from 2006 to 2015. He led the Cowboys to four postseason appearances during his tenure, while also receiving Pro Bowl honors amid each playoff run. Romo retired after the 2016 season when a preseason back injury caused him to lose his starting position to backup Dak Prescott. Upon retiring, he was hired by CBS Sports to become the lead color analyst for their NFL telecasts.


title: Tony Romo

text: Romo holds several Cowboys team records, including passing touchdowns, passing yards, most games with at least 300 passing yards, and games with three or more touchdown passes. He also held a higher passer rating in the fourth quarter than any other NFL quarterback from 2006 to 2013. However, Romo's reputation was affected by a lack of postseason success, having won only two of the six playoff games he appeared in and never advancing beyond the divisional round. His 97.1 passer rating is the highest among retired players who never appeared in the Super Bowl.


title: Tony Romo

text: Romo was born in San Diego, California to Ramiro Romo Jr. and Joan Jakubowski. Romo is a "Navy brat," as he was born while his father was stationed at the San Diego U.S. Naval Base. The Romos later returned to Burlington, Wisconsin, where Ramiro worked as a carpenter and construction worker and his wife, Joan, worked as a grocery store clerk. Romo played baseball as a child and was selected to the Little League All-Star team.


title: Tony Romo

text: Romo's paternal grandfather, Ramiro Romo Sr., emigrated from Múzquiz, Coahuila, Mexico to San Antonio, Texas as an adolescent. The elder Romo cites Tony's success as an example of the possibilities afforded to immigrants in the United States: "I've always said this is a country of opportunities. If you don't get a job or an education, it's because you don't want to." Romo's mother has German and Polish ancestry.


title: Tony Romo

text: Romo started as quarterback for the Burlington High School Demons beginning as a junior (1996 season). In the 1997 season, Romo and the Demons finished with a 3–6 record, though he earned several honors, including the All-Racine County football team and Wisconsin Football Coaches Association All-State first team honors. Romo also was a starter on the Burlington High School varsity basketball team and also played golf and tennis. In 1998, he joined Caron Butler on the All-Racine County (Wisconsin) team. With per-game averages of 24.3 points, 8.8 rebounds and 4.7 assists, Romo was sought by some mid-major basketball schools in the NCAA such as Wisconsin-Green Bay. Romo graduated from Burlington High School in 1998, with his 1,080 points being the all-time scoring record for the Burlington basketball varsity.


title: Tony Romo

text: Romo attended Eastern Illinois University in Charleston, Illinois, where he played for the NCAA Division I-AA Eastern Illinois Panthers football team and was a member of Sigma Pi. As a sophomore in 2000, he ranked second in Division I-AA in passing efficiency, completing 164-of-278 (59%) passes for 2,583 yards and 27 touchdowns. After the season, he was honored as an All-America honorable mention, an All-Ohio Valley Conference member, and the OVC Player of the Year. As a junior, he led Division I-AA in passing efficiency, completing 138-of-207 passes for 2,068 yards and 21 touchdowns.


title: Tony Romo

text: Romo earned OVC Player of the Week honors on October 14, 2002, after his eight-yard scramble run on the last play of the game led Eastern Illinois to a 25–24 win over Eastern Kentucky.


title: Tony Romo

text: On December 19, 2002, Romo became the first player in Eastern Illinois and Ohio Valley Conference history to win the Walter Payton Award, given annually to the top Division I-AA football player. He finished his career holding school and conference records with 85 touchdown passes. He finished second in school and third in conference history with 8,212 passing yards and second in school history with 584 completions and 941 attempts. As a senior, he set school and conference records for completions with 258 in 407 attempts for 3,418 yards. This was second in conference and third in school history for a season. He threw for 34 touchdowns and scored one rushing touchdown. Romo's 3,149 yards in total offense as a senior ranked third in school and conference history. Along with the Walter Payton Award, Romo earned consensus All-America honors. In addition, he was selected All-Ohio Valley Conference and was named OVC Player of the Year for the third straight year.


title: Tony Romo

text: During homecoming weekend on October 17, 2009, Eastern Illinois University retired Romo's No. 17 jersey and inducted him into EIU's Hall of Fame. Romo is the first Eastern Illinois player to have his number retired. He said about the event, "It was such an honor to be inducted into the Hall of Fame here, and with the jersey ceremony, it holds a special place in your heart."


title: Tony Romo

text: On December 7, 2021, Romo was inducted to the College Football Hall of Fame as a member of the 2021 class.


title: Tony Romo

text: Romo did not initially receive an invitation to attend the 2003 NFL Combine, but received a late invitation to attend as an extra quarterback to throw passes to other prospects during drills. Despite intriguing some scouts, he went undrafted by any NFL team during the 2003 NFL Draft. Throughout the draft, Romo was assured by Dallas assistant head coach Sean Payton of the Cowboys' interest (Romo was also intensely pursued by Denver Broncos head coach Mike Shanahan), and shortly afterwards was signed as an undrafted rookie free agent by the Cowboys. Romo entered the 2003 training camp third on the Cowboys' depth chart behind Quincy Carter and Chad Hutchinson. In 2004, the Cowboys released Hutchinson and signed veteran quarterback Vinny Testaverde and traded a third-round draft pick to the Houston Texans for quarterback Drew Henson. Romo faced being cut from the roster until Carter was released following allegations of substance abuse. Throughout 2004 and 2005, Romo served as the holder for placekicks. After Vinny Testaverde's tenure in Dallas ended in 2005, the Cowboys signed veteran quarterback Drew Bledsoe, the team's eighth starting quarterback since 2000.


title: Tony Romo

text: One of Romo's early career highlights was in 2004, when (as the third-string quarterback) he rushed for the winning touchdown with six seconds left in a preseason game against the Oakland Raiders. Elevated to the Cowboys' second quarterback in 2005, Romo had strong showings in the 2005 and 2006 pre-seasons. In the 2006 off-season, Sean Payton (now head coach of the New Orleans Saints), offered a third-round draft pick for Romo, but Cowboys' owner Jerry Jones refused, asking for no less than a second-round draft pick.


title: Tony Romo

text: Romo began the season as a backup to starter Drew Bledsoe. He took his first regular season snap at quarterback in a home game against the Houston Texans on October 15. His first NFL pass was a 33-yard completion to wide receiver Sam Hurd. His only other pass of the game was a two-yard touchdown pass, his first in the NFL, to wide receiver Terrell Owens.


title: Tony Romo

text: One week later, Romo replaced Bledsoe for the start of the second half of a game against the New York Giants. His first pass was tipped and intercepted. He finished with 227 yards, two touchdowns, and three interceptions (one of which was returned for a touchdown). On October 25, Cowboys head coach Bill Parcells announced that Romo would be the Cowboys starting quarterback for the October 29 game against the Carolina Panthers on "NBC Sunday Night Football", in Week 8. Romo led the Cowboys to victory in his first game as a starter, 35–14.


title: Tony Romo

text: On November 19, Romo led the Cowboys past the Indianapolis Colts, the NFL's last unbeaten team. He completed 19 of 23 passes as the Cowboys won against the Colts 21–14. Four days later he helped the Cowboys win in a Thanksgiving Day game against the Tampa Bay Buccaneers by the score of 38–10. Romo went 22–29 with 306 yards and a career-high five touchdown passes. In the month of November, Romo won NFC Offensive Player of the Week twice, once for the Week 10 game against Arizona and the other for Week 12 against Tampa Bay.


title: Tony Romo

text: Romo aided the Cowboys in clinching a playoff spot, their second since Parcells became coach in 2003. He concluded the 2006 regular season with 220 completions on 337 pass attempts for 2,903 yards, 19 touchdowns, and 13 interceptions, with a passer rating of 95.1.


title: Tony Romo

text: The Cowboys played the Seattle Seahawks in the NFC on January 6, 2007. With the Cowboys trailing 21–20 on fourth-and-one with 1:19 left in the game, the Cowboys attempted a 19-yard field goal. Romo, the holder for the kick, fumbled the snap. He recovered the ball and attempted to run it in, but was tackled short of the first down marker, and turned the ball over on the Seattle 2-yard line. The Cowboys went on to lose the game. Romo finished the 2006 season ranked seventh in the NFC in passing yards (2,903) and touchdown passes (19).


title: Tony Romo

text: Romo played in the 2007 Pro Bowl after Drew Brees went down with an elbow injury as a substitution for Marc Bulger. He threw one touchdown and one interception, and was the NFC's kickoff holder in the game.


title: Tony Romo

text: Romo began the 2007 season with four touchdown passes and an additional touchdown rush, the first of his career, defeating the New York Giants 45–35 in the Cowboys' first game of the regular season He earned NFC Offensive Player of the Week for Week 1. Romo added 329 passing yards and two touchdown passes in the Cowboys' Week 3 34–10 win over the Chicago Bears. The following week, he passed for 339 yards and three touchdowns in a 35–7 win over the St. Louis Rams. He ran for an additional touchdown. Romo earned NFC Offensive Player of the Month for September. In September 2007, Romo's father was diagnosed with prostate cancer. Romo stated that, while upset about the family crisis, he still had to continue to focus on his career.


title: Tony Romo

text: In Week 5, on "Monday Night Football" against the Buffalo Bills, Romo threw five interceptions (four in the first half, two of which were returned for touchdowns) and lost a fumble in the 25–24 victory. He became the second person in the history of "Monday Night Football" to throw five interceptions in a winning effort.


title: Tony Romo

text: On October 29, Romo reached an agreement to a six-year, $67.5 million contract extension with the Cowboys.


title: Tony Romo

text: On November 29 against the Green Bay Packers, in a game between 10–1 teams, Romo threw four touchdown passes (bringing his season total to 33), breaking Danny White's (29) record from 1983. He earned NFC Offensive Player of the Week for his game against the Packers. On December 22 against the Carolina Panthers, Romo became the first Cowboys' quarterback to pass for more than 4,000 yards in a season. December 30 against the Washington Redskins, Romo broke the Cowboys' season completions record with his 335th completion, a short pass to tight end Jason Witten. The Cowboys finished the season with a 13–3 record. He finished the 2007 season with 4,211 passing yards, 36 touchdowns, and 19 interceptions. He earned a second consecutive Pro Bowl nomination.


title: Tony Romo

text: In the Cowboys' game against the New York Giants, Romo was unable to lead his team to a come-from-behind victory. On fourth down with less than half a minute and no timeouts left, Romo threw the ball into the end zone, but it was intercepted by Giants cornerback R. W. McQuarters, ensuring that the Cowboys were eliminated from the playoffs with a 21–17 loss to the eventual Super Bowl XLII champions.


title: Tony Romo

text: On September 7, 2008, Romo led the Cowboys to a 28–10 win over the Cleveland Browns in their season opener. Romo completed 24 of his 32 passes for a total of 320 yards and one touchdown. After the game, Romo required 13 stitches for a large gash on his chin that occurred during the third quarter when linebacker Willie McGinest hit him in the chin with his helmet. The NFL fined McGinest $7,500 for the hit.


title: Tony Romo

text: On September 15, Romo led the Dallas Cowboys to a 41–37 win against the Philadelphia Eagles in the second game of the 2008 season. Romo completed 21 of his 30 passes for a total of 312 yards and three touchdowns. The 54 combined points scored by the Cowboys and Eagles in the first half were the second most points scored in a half during a "Monday Night Football" game. That same month, Romo signed a 5-year, $10 million endorsement deal with apparel marketer Starter, but was not allowed to wear footwear on the field as the company did not have a contract with the NFL.


title: Tony Romo

text: Romo and the Cowboys won their third straight before losing to the Washington Redskins, falling to 3–1. Following a win against the Cincinnati Bengals, Romo was injured in a loss to the Arizona Cardinals. The Cowboys, under Brad Johnson, went 1–2 the next three games, losing to the St. Louis Rams, beating the Tampa Bay Buccaneers, and losing to the New York Giants.


title: Tony Romo

text: In what became a "de facto" third playoff game for Romo shortly prior to its start, on December 28, Romo and the Cowboys failed to compete against the Philadelphia Eagles in a 44–6 loss. Romo committed three turnovers in the game and threw for 183 yards and no touchdowns. The loss dropped Romo's combined record in December to 5–8 and again raised questions about his performance in games of consequence.


title: Tony Romo

text: Romo led the Cowboys to a 34–21 win over the Tampa Bay Buccaneers in their season opener. He completed 16 of his 27 passes for a then-career-high 353 yards along with three touchdowns.


title: Tony Romo

text: Romo and the Cowboys were defeated in week 2 against the New York Giants in the Cowboys home opener at their new Cowboys Stadium. Romo completed 13 of 29 passes for 127 yards and one touchdown. He also threw three interceptions, one of which was returned for a touchdown for the Giants.


title: Tony Romo

text: In a Week 13 road game against the division rival New York Giants, Romo passed for a career-high 392 yards, along with three touchdown passes. He completed a career-high 41 passes in the 31–24 setback.


title: Tony Romo

text: After several kicks were missed by kicker Nick Folk due to bad holds by punter Mat McBriar, Romo resumed holding duties for the first time since the 2006 in their 13th game of the season, versus the San Diego Chargers.


title: Tony Romo

text: In Week 15, Romo led the Cowboys to a win against an undefeated team late in the season for the second time in his career. On December 19, 2009, he defeated the 13–0 Saints at New Orleans, throwing for 312 yards and one touchdown. He earned NFC Offensive Player of the Month for December.


title: Tony Romo

text: Romo finished the 2009 season as the first quarterback in team history to take every snap for a full season. He also passed his own mark for single season passing yardage, with 4,483 yards, and became the first Cowboys quarterback to throw more than 20 touchdowns and fewer than ten interceptions in a season. His eight 300 yard games was also a team record, surpassing his own record from 2007. His 1.6% interception percentage tied a team record, and his career interception percentage became the lowest in franchise history.


title: Tony Romo

text: The Dallas Cowboys became the NFC East division champions with their season finale shutout of the Philadelphia Eagles, the second division title in Romo's three full seasons as the starting quarterback. Romo was named to the Pro Bowl for the third time in his career.


title: Tony Romo

text: Romo had a 104.9 passer rating in a 34–14 win over the Philadelphia Eagles in the of the playoffs, earning the first playoff win in 13 years for the Cowboys, and his own first career post-season win. However, the following week in the against the number two seed Minnesota Vikings, Romo had three fumbles (losing two), an interception and was sacked six times in the 34–3 loss.


title: Tony Romo

text: In Week 5 against the Tennessee Titans, Romo threw for a career-high 406 yards and three touchdowns. However, he also threw two costly interceptions in the fourth quarter, resulting in 34–27 loss at Cowboys Stadium. Romo and the Cowboys were desperate for a win with a record of 1–3 and last in the division. They played against the Minnesota Vikings, who also had a 1–3 record and were in need of a win. Romo threw for over 200 yards and three touchdowns but also threw two costly interceptions. The Cowboys lost the game by a score of 24–21.


title: Tony Romo

text: During the October 25, 2010 "Monday Night Football" game against the New York Giants, Romo suffered a broken left clavicle. The injury occurred during the second quarter, when Romo was driven to the turf by Giants linebacker Michael Boley. He was placed on Injured Reserve on December 21, 2010, and replaced by veteran Jon Kitna. He was ranked 72nd by his fellow players on the NFL Top 100 Players of 2011.


title: Tony Romo

text: Romo's 102.5 quarterback rating in 2011 was fourth best in the league behind Aaron Rodgers, Drew Brees, and Tom Brady, and second highest in Cowboys history.


title: Tony Romo

text: In Week 2 against the San Francisco 49ers, Romo suffered a broken rib and a punctured lung on a hit from Carlos Rogers in the second quarter that forced him to miss part of the game. Romo came back in the final seconds of the third quarter and played the fourth quarter throwing for a touchdown and driving down the field for the game-tying field goal with four seconds left in the game to force overtime. On the first offensive possession for the Cowboys in overtime, Romo connected with Jesse Holley for 77 yards to set up the 19 yard game-winning field goal. Romo finished the game with 345 yards and two touchdowns with a 116.4 rating despite the cracked rib and punctured lung. For his performance in this game, Romo earned the NFC's Offensive player of the Week Award. Romo played with a protective vest for a few games to protect his torso.


title: Tony Romo

text: In Week 10, Romo posted the second highest quarterback rating of his career with a rating of 148.40 in Week 10 against the Buffalo Bills.


title: Tony Romo

text: In Week 16 against the Philadelphia Eagles, Romo suffered a severely bruised hand when he smashed it against an opposing player's helmet. He left the game after attempting just two passes with no completions. The next week, in the season finale at MetLife Stadium against the Giants, the NFC East title and a playoff spot was at stake for whichever team won, with the loser eliminated from playoff contention. Romo started the game despite the hand injury the previous week. He posted 29 out of 37 passing for 289 yards, two touchdowns and one interception for a 106.0 quarterback rating and a 78% pass completion rate (second highest of the season) as the Cowboys lost the game 31–14, dropped to an 8–8 record and were eliminated from playoff contention.


title: Tony Romo

text: Romo accounted for 32 of the 39 total touchdowns the Cowboys scored in the 2011 NFL season (82.1%). No other player in the 2011 regular season contributed a higher percentage of team touchdowns (Cam Newton with 72.9% was second). Romo finished the 2012 season with 4,184 passing yards, 31 passing touchdowns, and ten interceptions. He was ranked 91st by his fellow players on the NFL Top 100 Players of 2012.


title: Tony Romo

text: Daniel Jeremiah, an NFL.com analyst, ranked Romo as the 9th best quarterback in the league heading into the 2012 season.


title: Tony Romo

text: Romo started the 2012 season with 307 passing yards, three passing touchdowns, and one interception in the 24–17 victory over the New York Giants. In Week 8, in the second divisional matchup with the New York Giants, he passed for 437 passing yards, one passing touchdown, and four interceptions. He attempted a career-high 62 passes in the 29–24 loss. In Week 12, against Washington, he passed for 441 yards, three touchdowns, and two interceptions. He matched his career-best 62 pass attempts in the 38–31 loss. In Week 13 against the Philadelphia Eagles, Romo threw three touchdown passes. The first pass, a 23-yard throw to Dez Bryant with 11:18 left in the third quarter, gave Romo 166 career touchdown passes, surpassing the previous franchise record of 165 which had been held by Troy Aikman.


title: Tony Romo

text: After trailing the Cincinnati Bengals 19–10 with 6:35 left, Dallas beat Cincinnati 20–19 in Week 14 (December 9). The fourth quarter comeback consisted of a 27-yard touchdown pass from Romo to Bryant and a last-second 40-yard field goal by Bailey. Romo went 25-for-43 for 268 yards, with one touchdown and one interception.


title: Tony Romo

text: Topping a three-game winning streak and winning its fifth out of six games, Dallas beat the Pittsburgh Steelers 27–24 in overtime in Week 15 (December 16). The win put Dallas in a three-way tie with New York and Washington in the NFC East. Romo surpassed 25,000 career passing yards in this game with 30-for-42 passing for 341 yards and two touchdowns.


title: Tony Romo

text: On Week 16 (December 23), despite Romo's four touchdown passes and 416 passing yards (on 26-for-43 passing), Dallas lost to the New Orleans Saints, 37–34, in overtime. Following that game, Dallas and the Washington Redskins faced off in Week 17 for the NFC East title, where Dallas lost 28–18. With overall 20-for-37 passing, Romo threw a total of three interceptions, including on Dallas' first two drives. With 5:50 left and down 21–10, Romo made a touchdown pass to Kevin Ogletree and two-point conversion pass to Dwayne Harris. After Dallas took over with 3:33 left down 21–18, Romo threw an interception to Redskins linebacker Rob Jackson, and Washington clinched the victory with another touchdown. Dallas finished the 2012 season with an 8–8 record and failed to make the playoffs for the third straight season. While his 19 interceptions led the league, he was credited with five fourth-quarter comebacks.


title: Tony Romo

text: Following the season, the future of Romo's career was called into question. Mac Engel of the "Fort Worth Star-Telegram" commented: "Tony Romo has one year remaining on his contract, but the time has come for him to move on...He will be 33 in April of '13, and still has a few good years left but at this point he needs to go to another team that needs a quarterback." In a Fox Sports Southwest interview, Rick Gosselin of "The Dallas Morning News" also called Romo "not wired to win the last game of the season" especially "[i]f it means extending the season." Dan Graziano of ESPNDallas.com wrote that Romo's "record starts to become very hard to defend" due to "the oft-cited fact that he's got just the one playoff win in his entire career."


title: Tony Romo

text: The Cowboys signed Romo to a 6-year extension worth $108 million, with $55 million guaranteed and $25 million in bonuses, thus securing him for the rest of his career and relieving the pressure from the salary cap, which was reported to have less than $25,000 space before the deal was struck. In the middle of April 2013, he underwent back surgery to remove a cyst. Although it was characterized as a minor procedure by the team, he would end up missing all of the mini-camp and organized team activities.


title: Tony Romo

text: Romo opened the season with a win over the New York Giants, passing for 263 yards and two touchdowns. He briefly left the game with a rib injury, but returned after halftime and finished the game. After Week 7, his 100th career start, Romo had thrown for 27,485 yards, the most by a quarterback in his first 100 starts since 1960. In Week 5, against the Denver Broncos, Romo passed for a franchise-record 506 passing yards, five passing touchdowns, and one interception in the 51–48 loss. The game was a memorable back-and-forth shootout between the two teams with Romo and Peyton Manning at the helm.


title: Tony Romo

text: In Week 16, against the Washington Redskins, with the Cowboys trailing in the fourth quarter and needing a win to keep its playoff hopes alive, he led the team to a touchdown drive with 1:08 remaining in a 24–23 victory, with what was later diagnosed as a season-ending herniated disk injury. Head coach Jason Garrett would later say: "He might have had his finest hour … We talk about mental toughness, being your best, regardless of circumstances. Somehow, some way, he helped us win that ballgame."


title: Tony Romo

text: Romo underwent back surgery on December 27, 2013, and was placed on the Cowboys' injured reserve list. Garrett announced Kyle Orton as the starting quarterback for the Week 17 game against the Philadelphia Eagles, which the team lost 24–22, to miss the playoffs for a fourth straight year. Romo finished the 2013 season with 3,828 passing yards, 31 passing touchdowns, and ten interceptions. He was ranked 71st by his fellow players on the NFL Top 100 Players of 2014


title: Tony Romo

text: After a poor performance in the season opening 28–17 loss versus the San Francisco 49ers, Romo and the Cowboys won six consecutive games, including back-to-back road games against the Tennessee Titans and the St. Louis Rams. The Cowboys also defeated the defending champion Seattle Seahawks on the road, becoming only the second team to win a road game against the Seahawks in the three seasons. In Week 5, against the Houston Texans, Romo pulled off a memorable escape from J. J. Watt's pursuit on a play that resulted in Romo throwing a 43-yard touchdown in the 20–17 victory. Through those six wins, Romo had a 13:3 touchdown:interception ratio. In Week 8, against the Washington Redskins, Romo went down with a back injury when linebacker Keenan Robinson sacked him, with his knee going into Romo's back. After the loss to Washington, it was revealed that Romo had two fractures in his transverse process. He missed the next game, a 28–17 loss to the Arizona Cardinals, but came back the next week and went on to lead the Cowboys to a 12–4 record and their first divisional title since 2009.


title: Tony Romo

text: On December 21, Romo set the Dallas Cowboys team record for highest completion percentage in a game with 90%, completing 18 of his 20 passes in a 42–7 blowout win over the Indianapolis Colts. He set his personal best quarterback rating in a single game with 151.7. Romo's 133.7 passer rating in the month of December was the highest in NFL history. He was named NFC Offensive Player of the Month for December. He was named to the Pro Bowl.


title: Tony Romo

text: In the of the playoffs, Romo led the Cowboys to a 24–20 comeback victory over the Detroit Lions after being down 17–7 at halftime. Romo was 19-of-31 for 293 yards with two touchdowns and no interceptions. In the Divisional Round, Romo and the Cowboys were defeated by the Green Bay Packers, 26–21. Romo was 15-of-19 for 191 yards with two touchdowns and no interceptions. Romo was involved in a controversial sequence in the fourth quarter of the game. Romo completed a 31-yard pass to Dez Bryant on a fourth-and-2 play from the Packers' 32-yard line. Although Bryant caught the ball with both feet down in bounds, Bryant bobbled the ball as he made an attempt to reach for the endzone. Referees initially ruled Bryant down at the 1-yard line, but overturned the call as an incomplete pass following a challenge from the Packers.


title: Tony Romo

text: Romo led the NFL in completion percentage and passer rating en route to the NFC East title. He finished tied for 3rd in MVP voting. He was ranked 34th by his fellow players on the NFL Top 100 Players of 2015. He was the highest undrafted player on the year's list.


title: Tony Romo

text: Romo started strong in the 2015 season, throwing a game-winning pass to Jason Witten with seven seconds left in the Cowboys' season opener against the New York Giants. He passed for 356 yards, three touchdowns, and two interceptions in the 27–26 victory. He continued to show success in a Week 2 victory over the Philadelphia Eagles, but suffered a broken left collarbone in the third quarter after being sacked by linebacker Jordan Hicks. The injury sidelined Romo for eight weeks, during which the Cowboys failed to win a single game with Brandon Weeden and then Matt Cassel as starting quarterback.


title: Tony Romo

text: Romo returned to the starting lineup in a Week 11 game against the Miami Dolphins. Despite throwing two interceptions, he completed 18 of 28 passes for 227 yards and two touchdowns in a 24–14 victory, ending the Cowboys' seven-game losing streak.


title: Tony Romo

text: The Cowboys then faced the 10–0 Carolina Panthers in a Week 12 Thanksgiving game. Although up against an undefeated team and holding only a 3–7 record, the Romo-led Cowboys were favored to win and still had hopes for the playoffs in a weak NFC East division. However, Romo threw three interceptions in the first half, two of which were returned for touchdowns, helping the Panthers take a 23–3 lead. At the end of the third quarter, Romo was sacked by linebacker Thomas Davis, reinjuring his left shoulder and ending his season. Romo remained on the active roster until December 21 when he was placed on injured reserve after the Cowboys dropped to 4–10, officially ending their playoff hopes.


title: Tony Romo

text: Romo was unable to start in the 2016 regular season after suffering a compression fracture to the L1 vertebra in his back during the Cowboys' third preseason game against the Seattle Seahawks. The injury caused him to miss the first 10 games of the season, with the duties of the team's starting quarterback being assumed by rookie Dak Prescott.


title: Tony Romo

text: Although Cowboys owner Jerry Jones initially said Romo would remain the team's starter when he returned, Prescott's success with the team and the length of Romo's injury led to Jones reconsidering his decision. Amid Prescott guiding the team to an eight-game winning streak, Romo conceded his role as starting quarterback to Prescott and began serving as the Cowboys' backup when he returned to the active roster in Week 11. Romo made his season debut in the regular season finale on January 1, 2017, against the Philadelphia Eagles. In what would prove to be the final play of his career, he threw a touchdown pass to Terrance Williams before Mark Sanchez played the rest of the game.


title: Tony Romo

text: On April 4, 2017, Romo announced his retirement from the NFL. After announcing his retirement, he was released by the Cowboys, per his request. Following his retirement, Dallas Mavericks owner Mark Cuban announced that Romo would be a "Maverick for a day" for the Mavericks' final home game of their 2016–17 season. He warmed up with the team and sat in full uniform on the bench, but did not play in the game and was not considered an official member of the roster.


title: Tony Romo

text: Following his retirement from the NFL, he was hired by CBS Sports to serve as the lead color analyst for the network's NFL telecasts, working in the booth alongside play-by-play announcer Jim Nantz, replacing Phil Simms, who was moved to the studio for "The NFL Today".


title: Tony Romo

text: While there was no controversy of Romo deciding to retire and move on to broadcasting, some critics questioned Romo being immediately hired for the number one position ahead of broadcasting veterans Dan Fouts, Trent Green, or Rich Gannon, all of whom served in the number 2–4 positions respectively for CBS, with Fouts having once been the color commentator on "Monday Night Football". None of the ex-players and coaches in a lead position on other networks at the time of Romo's hiring (Troy Aikman, Cris Collinsworth, and Jon Gruden) started their broadcasting career in the lead position. Simms jokingly asked Romo "How does that seat feel?" during Week 1 of "The NFL Today".


title: Tony Romo

text: Once the 2017 NFL season got underway, Romo received critical praise for his work as a recent ex-player, most notably for his ability to predict offensive plays and read defensive formations from the booth, and "adding an enthusiasm that had been lacking with Simms."


title: Tony Romo

text: Romo and Nantz received further acclaim for their broadcasting of the 2018 AFC Championship Game between the Kansas City Chiefs and the New England Patriots, as "Nantz continually set Romo up to make his predictions and analysis prior to the snap", and some suggested that Chiefs head coach "Andy Reid could have used Romo on his defensive staff, because the former quarterback knew just about every play the Patriots were going to run down the stretch." According to "The Guardian", the "beauty of Romo's analysis is that it feels like he's in on the fun with you." Romo and Nantz called Super Bowl LIII in Atlanta.


title: Tony Romo

text: "The New Yorker" has called him a "genius of football commentary." Romo has received praise from other prominent sports commentators, including Bob Costas and Dick Vitale.


title: Tony Romo

text: In February 2020, Romo renewed his contract with CBS through at least 2022, with the network reportedly paying him $17 million per year, which would make Romo one of the highest-paid personnel in sports broadcasting and "the highest-paid NFL analyst in television history."


title: Tony Romo

text: In 2018, Romo filled the vacancy of Jon Gruden in Corona's "Corona Hotline" commercials. Romo has maintained his recurring position in the series of advertisements, and many of the television ad spots feature his fantasy football advice.


title: Tony Romo

text: , Romo hosted a youth football camp in Burlington, Wisconsin, annually during the summer, since 2004. In the Dallas area, Romo participated in community activities in collaboration with United Way, the Make-A-Wish Foundation, and the Society for the Prevention of Cruelty to Animals.


title: Tony Romo

text: In November 2007, Romo began dating American singer and actress Jessica Simpson. On December 16, 2007, Simpson attended a Dallas Cowboys–Philadelphia Eagles game at Texas Stadium, in which Romo had a bad performance in the loss to the Eagles. Controversy erupted before the playoff game against the New York Giants—a game the Cowboys would lose—when pictures surfaced of Romo (along with teammates Jason Witten and Bobby Carpenter) at a resort in Cabo San Lucas with Simpson. On July 13, 2009, "People" reported that Romo and Simpson broke up on July 9, 2009, the night before her 29th birthday.


title: Tony Romo

text: On May 28, 2011, Romo married Candice Crawford, the 2008 Miss Missouri USA, a former journalist for Dallas television station KDAF, and the sister of actor Chace Crawford. They had dated since the summer of 2009, and became engaged on December 16, 2010. The couple have three sons together: Hawkins Crawford Romo (born April 9, 2012), Rivers Romo (born March 18, 2014), and Jones McCoy Romo (born August 23, 2017).


title: Tony Romo

text: Romo is an avid amateur golfer, and attempted to qualify for the 2004 EDS Byron Nelson Championship and the 2005 U.S. Open, but failed. During the offseason, when not training, he plays golf around Dallas. He failed to make the cut in qualifying for Byron Nelson in 2008. In February 2018, it was announced that he had received a sponsor's exemption to play in the PGA Tour's Corales Puntacana Resort and Club Championship in Punta Cana, Dominican Republic from March 22–25. Romo missed the cut with scores of 77 and 82, dead last in the 132-man field after the second round. In July 2018, he won the American Century Championship, a celebrity tournament.


title: Tony Romo

text: Romo is a Christian and has spoken about his faith saying, "My faith has grown and I found that always having Jesus makes things a lot easier in my life. Having Jesus in your life gives you everlasting peace, which never goes away. It helps you handle the ups and downs of professional football."


title: Blood pressure

text: Blood pressure (BP) is the pressure of circulating blood against the walls of blood vessels. Most of this pressure results from the heart pumping blood through the circulatory system. When used without qualification, the term "blood pressure" refers to the pressure in the large arteries. Blood pressure is usually expressed in terms of the systolic pressure (maximum pressure during one heartbeat) over diastolic pressure (minimum pressure between two heartbeats) in the cardiac cycle. It is measured in millimeters of mercury (mmHg) above the surrounding atmospheric pressure.


title: Blood pressure

text: Blood pressure is one of the vital signs—together with respiratory rate, heart rate, oxygen saturation, and body temperature—that healthcare professionals use in evaluating a patient's health. Normal resting blood pressure, in an adult is approximately systolic over diastolic, denoted as "120/80 mmHg". Globally, the average blood pressure, age standardized, has remained about the same since 1975 to the present, at approx. 127/79 mmHg in men and 122/77 mmHg in women, although these average data mask significantly diverging regional trends.


title: Blood pressure

text: Traditionally, a health-care worker measured blood pressure non-invasively by auscultation (listening) through a stethoscope for sounds in one arm's artery as the artery is squeezed, closer to the heart, by an aneroid gauge or a mercury-tube sphygmomanometer. Auscultation is still generally considered to be the gold standard of accuracy for non-invasive blood pressure readings in clinic. However, semi-automated methods have become common, largely due to concerns about potential mercury toxicity, although cost, ease of use and applicability to ambulatory blood pressure or home blood pressure measurements have also influenced this trend. Early automated alternatives to mercury-tube sphygmomanometers were often seriously inaccurate, but modern devices validated to international standards achieve an average difference between two standardized reading methods of 5 mm Hg or less, and a standard deviation of less than 8 mm Hg. Most of these semi-automated methods measure blood pressure using oscillometry (measurement by a pressure transducer in the cuff of the device of small oscillations of


title: Blood pressure

text: Blood pressure is influenced by cardiac output, systemic vascular resistance, blood volume, arterial stiffness and varies depending of patient's situation, emotional state, activity, and relative health or disease state. In the short term, blood pressure is regulated by baroreceptors, which act via the brain to influence the nervous and the endocrine systems.


title: Blood pressure

text: Blood pressure that is too low is called hypotension, pressure that is consistently too high is called hypertension, and normal pressure is called normotension. Both hypertension and hypotension have many causes and may be of sudden onset or of long duration. Long-term hypertension is a risk factor for many diseases, including stroke, heart disease, and kidney failure. Long-term hypertension is more common than long-term hypotension.


title: Blood pressure

text: The risk of cardiovascular disease increases progressively above 115/75 mmHg, below this level there is limited evidence.


title: Blood pressure

text: Observational studies demonstrate that people who maintain arterial pressures at the low end of these pressure ranges have much better long-term cardiovascular health. There is an ongoing medical debate over what is the optimal level of blood pressure to target when using drugs to lower blood pressure with hypertension, particularly in older people.


title: Blood pressure

text: The table shows the 2018 classification of office (or clinic) blood pressure by The Task Force for the management of arterial hypertension of the European Society of Cardiology (ESC) and the European Society of Hypertension (ESH). Similar thresholds had been adopted by the American Heart Association for adults who are 18 years and older, but in November 2017 the American Heart Association announced revised definitions for blood pressure categories that increased the number of people considered to have high blood pressure.


title: Blood pressure

text: Blood pressure fluctuates from minute to minute and normally shows a circadian rhythm over a 24-hour period, with highest readings in the early morning and evenings and lowest readings at night. Loss of the normal fall in blood pressure at night is associated with a greater future risk of cardiovascular disease and there is evidence that night-time blood pressure is a stronger predictor of cardiovascular events than day-time blood pressure. Blood pressure varies over longer time periods (months to years) and this variability predicts adverse outcomes. Blood pressure also changes in response to temperature, noise, emotional stress, consumption of food or liquid, dietary factors, physical activity, changes in posture (such as standing-up), drugs, and disease. The variability in blood pressure and the better predictive value of ambulatory blood pressure measurements has led some authorities, such as the National Institute for Health and Care Excellence (NICE) in the UK, to advocate for the use of ambulatory blood pressure as the preferred method for diagnosis of hypertension.


title: Blood pressure

text: Various other factors, such as age and sex, also influence a person's blood pressure. Differences between left-arm and right-arm blood pressure measurements tend to be small. However, occasionally there is a consistent difference greater than 10 mmHg which may need further investigation, e.g. for peripheral arterial disease, obstructive arterial disease or aortic dissection.


title: Blood pressure

text: There is no accepted diagnostic standard for hypotension, although pressures less than 90/60 are commonly regarded as hypotensive. In practice blood pressure is considered too low only if symptoms are present.


title: Blood pressure

text: In pregnancy, it is the fetal heart and not the mother's heart that builds up the fetal blood pressure to drive blood through the fetal circulation. The blood pressure in the fetal aorta is approximately 30 mmHg at 20 weeks of gestation, and increases to approximately 45 mmHg at 40 weeks of gestation.


title: Blood pressure

text: In children, the normal ranges for blood pressure are lower than for adults and depend on height. Reference blood pressure values have been developed for children in different countries, based on the distribution of blood pressure in children of these countries.


title: Blood pressure

text: In adults in most societies, systolic blood pressure tends to rise from early adulthood onward, up to at least age 70; diastolic pressure tends to begin to rise at the same time but to start to fall earlier in mid-life, approximately age 55. Mean blood pressure rises from early adulthood, plateauing in mid-life, while pulse pressure rises quite markedly after the age of 40. Consequently, in many older people, systolic blood pressure often exceeds the normal adult range, if the diastolic pressure is in the normal range this is termed isolated systolic hypertension. The rise in pulse pressure with age is attributed to increased stiffness of the arteries. An age-related rise in blood pressure is not considered healthy and is not observed in some isolated unacculturated communities.


title: Blood pressure

text: Blood pressure generally refers to the arterial pressure in the systemic circulation. However, measurement of pressures in the venous system and the pulmonary vessels plays an important role in intensive care medicine but requires invasive measurement of pressure using a catheter.


title: Blood pressure

text: Venous pressure is the vascular pressure in a vein or in the atria of the heart. It is much lower than arterial pressure, with common values of 5 mmHg in the right atrium and 8 mmHg in the left atrium.


title: Blood pressure

text: Increased blood pressure in the capillaries of the lung causes pulmonary hypertension, leading to interstitial edema if the pressure increases to above 20 mmHg, and to pulmonary edema at pressures above 25 mmHg.


title: Blood pressure

text: If the heart is stopped, blood pressure falls, but it does not fall to zero. The remaining pressure measured after cessation of the heart beat and redistribution of blood throughout the circulation is termed the mean systemic pressure or mean circulatory filling pressure; typically this is proximally ~7mm Hg.


title: Blood pressure

text: Disorders of blood pressure control include high blood pressure, low blood pressure, and blood pressure that shows excessive or maladaptive fluctuation.


title: Blood pressure

text: Arterial hypertension can be an indicator of other problems and may have long-term adverse effects. Sometimes it can be an acute problem, for example hypertensive emergency.


title: Blood pressure

text: Levels of arterial pressure put mechanical stress on the arterial walls. Higher pressures increase heart workload and progression of unhealthy tissue growth (atheroma) that develops within the walls of arteries. The higher the pressure, the more stress that is present and the more atheroma tend to progress and the heart muscle tends to thicken, enlarge and become weaker over time.


title: Blood pressure

text: Persistent hypertension is one of the risk factors for strokes, heart attacks, heart failure, and arterial aneurysms, and is the leading cause of chronic kidney failure. Even moderate elevation of arterial pressure leads to shortened life expectancy. At severely high pressures, mean arterial pressures 50% or more above average, a person can expect to live no more than a few years unless appropriately treated.


title: Blood pressure

text: In the past, most attention was paid to diastolic pressure; but nowadays it is recognized that both high systolic pressure and high pulse pressure (the numerical difference between systolic and diastolic pressures) are also risk factors. In some cases, it appears that a decrease in excessive diastolic pressure can actually increase risk, probably due to the increased difference between systolic and diastolic pressures. If systolic blood pressure is elevated (>140 mmHg) with a normal diastolic blood pressure (<90 mmHg), it is called isolated systolic hypertension and may present a health concern. According to the 2017 American College of Cardiology/American Heart Association Blood Pressure Guidelines, "an {systolic blood pressure] of 130 mm Hg is now considered hypertensive at all ages." This will lead to more diagnoses of hypertension among all ages.


title: Blood pressure

text: For those with heart valve regurgitation, a change in its severity may be associated with a change in diastolic pressure. In a study of people with heart valve regurgitation that compared measurements two weeks apart for each person, there was an increased severity of aortic and mitral regurgitation when diastolic blood pressure increased, whereas when diastolic blood pressure decreased, there was a decreased severity.


title: Blood pressure

text: Blood pressure that is too low is known as hypotension. This is a medical concern if it causes signs or symptoms, such as dizziness, fainting, or in extreme cases, circulatory shock.


title: Blood pressure

text: A large fall in blood pressure upon standing (persistent systolic/diastolic blood pressure decrease of >20/10 mm Hg) is termed orthostatic hypotension (postural hypotension) and represents a failure of the body to compensate for the effect of gravity on the circulation. Standing results in an increased hydrostatic pressure in the blood vessels of the lower limbs. The consequent distension of the veins below the diaphragm (venous pooling) causes ~500 ml of blood to be relocated from the chest and upper body. This results in a rapid decrease in central blood volume and a reduction of ventricular preload which in turn reduces stroke volume, and mean arterial pressure. Normally this is compensated for by multiple mechanisms, including activation of the autonomic nervous system which increases heart rate, myocardial contractility and systemic arterial vasoconstriction to preserve blood pressure and elicits venous vasoconstriction to decrease venous compliance. Decreased venous compliance also results from an intrinsic myogenic increase in venous smooth muscle tone in response to the elevated pressure in the veins of the lower body. Other compensatory mechanisms include the veno-arteriolar axon reflex, the 'skeletal muscle pump' and 'respiratory pump'. Together these mechanisms normally stabilize blood pressure within a minute or less. If these compensatory mechanisms fail and arterial pressure and blood flow decrease beyond a certain point, the perfusion of the brain becomes critically compromised (i.e., the blood supply is not sufficient), causing lightheadedness, dizziness, weakness or fainting. Usually this failure of compensation is due to disease, or drugs that affect the sympathetic nervous system. A similar effect is observed following the experience of excessive gravitational forces (G-loading), such as routinely experienced by aerobatic or combat pilots 'pulling Gs' where the extreme hydrostatic pressures exceed the ability of the body's compensatory mechanisms.


title: Blood pressure

text: Some fluctuation or variation in blood pressure is normal. Variations in pressure that are significantly greater than the norm are associated with increased risk of cardiovascular disease brain small vessel disease, and dementia independent of the average blood pressure level. Recent evidence from clinical trials has also linked variation in blood pressure to mortality, stroke, heart failure, and cardiac changes that may give rise to heart failure. These data have prompted discussion of whether excessive variation in blood pressure should be treated, even among normotensive older adults. Older individuals and those who had received blood pressure medications are more likely to exhibit larger fluctuations in pressure, and there is some evidence that different antihypertensive agents have different effects on blood pressure variability; whether these differences translate to benefits in outcome is uncertain.


title: Blood pressure

text: During each heartbeat, blood pressure varies between a maximum (systolic) and a minimum (diastolic) pressure. The blood pressure in the circulation is principally due to the pumping action of the heart. However, blood pressure is also regulated by neural regulation from the brain (see Hypertension and the brain), as well as osmotic regulation from the kidney. Differences in mean blood pressure drive the flow of blood around the circulation. The rate of mean blood flow depends on both blood pressure and the resistance to flow presented by the blood vessels. In the absence of hydrostatic effects (e.g. standing), mean blood pressure decreases as the circulating blood moves away from the heart through arteries and capillaries due to viscous losses of energy. Mean blood pressure drops over the whole circulation, although most of the fall occurs along the small arteries and arterioles. Pulsatility also diminishes in the smaller elements of the arterial circulation, although some transmitted pulsatility is observed in capillaries. Gravity affects blood pressure via hydrostatic forces (e.g., during standing), and valves in veins, breathing, and pumping from contraction of skeletal muscles also influence blood pressure, particularly in veins.


title: Blood pressure

text: A simple view of the hemodynamics of systemic arterial pressure is based around mean arterial pressure (MAP) and pulse pressure. Most influences on blood pressure can be understood in terms of their effect on cardiac output, systemic vascular resistance, or arterial stiffness (the inverse of arterial compliance). Cardiac output is the product of stroke volume and heart rate. Stroke volume is influenced by 1) the end diastolic volume or filling pressure of the ventricle acting via the Frank Starling mechanism—this is influenced by blood volume; 2) cardiac contractility; and 3) afterload, the impedance to blood flow presented by the circulation. In the short-term, the greater the blood volume, the higher the cardiac output. This has been proposed as an explanation of the relationship between high dietary salt intake and increased blood pressure; however, responses to increased dietary sodium intake vary between individuals and are highly dependent on autonomic nervous system responses and the renin–angiotensin system, changes in plasma osmolarity may also be important. In the longer-term the relationship between volume and blood pressure is more complex. In simple terms, systemic vascular resistance is mainly determined by the caliber of small arteries and arterioles. The resistance attributable to a blood vessel depends on its radius as described by the Hagen-Poiseuille's equation (resistance∝1/radius). Hence, the smaller the radius, the higher the resistance. Other physical factors that affect resistance include: vessel length (the longer the vessel, the higher the resistance), blood viscosity (the higher the viscosity, the higher the resistance) and the number of vessels, particularly the smaller numerous, arterioles and capillaries. The presence of a severe arterial stenosis increases resistance to flow, however this increase in resistance rarely increases systemic blood pressure because its contribution to total systemic resistance is small, although it may profoundly decrease downstream flow. Substances called vasoconstrictors reduce the caliber of blood vessels, thereby increasing blood pressure. Vasodilators (such as nitroglycerin) increase the caliber of blood vessels, thereby decreasing arterial pressure. In the longer term a process termed remodeling also contributes to changing the caliber of small blood vessels and influencing resistance and reactivity to vasoactive agents. Reductions in capillary density, termed capillary rarefaction, may also contribute to increased resistance in some circumstances.


title: Blood pressure

text: In practice, each individual's autonomic nervous system and other systems regulating blood pressure, notably the kidney, respond to and regulate all these factors so that, although the above issues are important, they rarely act in isolation and the actual arterial pressure response of a given individual can vary widely in the short and long term.


title: Blood pressure

text: Mean Arterial Pressure (MAP) is the average of blood pressure over a cardiac cycle and is determined by the cardiac output (CO), systemic vascular resistance (SVR), and central venous pressure (CVP):


title: Blood pressure

text: MAP is often estimated from measurements of the systolic pressure, formula_3 and the diastolic pressure, formula_4  using the equation:


title: Blood pressure

text: The pulse pressure is a consequence of the pulsatile nature of the cardiac output, i.e. the heartbeat. The magnitude of the pulse pressure is usually attributed to the interaction of the stroke volume of the heart, the compliance (ability to expand) of the arterial system—largely attributable to the aorta and large elastic arteries—and the resistance to flow in the arterial tree.


title: Blood pressure

text: The endogenous, homeostatic regulation of arterial pressure is not completely understood, but the following mechanisms of regulating arterial pressure have been well-characterized:


title: Blood pressure

text: These different mechanisms are not necessarily independent of each other, as indicated by the link between the RAS and aldosterone release. When blood pressure falls many physiological cascades commence in order to return the blood pressure to a more appropriate level.


title: Blood pressure

text: Currently, the RAS is targeted pharmacologically by ACE inhibitors and angiotensin II receptor antagonists, also known as angiotensin receptor blockers (ARBs). The aldosterone system is directly targeted by spironolactone, an aldosterone antagonist. The fluid retention may be targeted by diuretics; the antihypertensive effect of diuretics is due to its effect on blood volume. Generally, the baroreceptor reflex is not targeted in hypertension because if blocked, individuals may experience orthostatic hypotension and fainting.


title: Blood pressure

text: Arterial pressure is most commonly measured via a sphygmomanometer, which uses the height of a column of mercury, or an aneroid gauge, to reflect the blood pressure by auscultation. The most common automated blood pressure measurement technique is based on the oscillometric method. Fully automated oscillometric measurement has been available since 1981. This principle has recently been used to measure blood pressure with a smartphone. Measuring pressure invasively, by penetrating the arterial wall to take the measurement, is much less common and usually restricted to a hospital setting.


title: Blood pressure

text: Novel methods to measure blood pressure without penetrating the arterial wall, and without applying any pressure on patient's body are currently being explored. So-called cuffless measurements, these methods open the door to more comfortable and acceptable blood pressure monitors. An example is a cuffless blood pressure monitor at the wrist that uses only optical sensors.


title: Blood pressure

text: One common problem in office blood pressure measurement in the United States is terminal digit preference. According to one study, approximately 40% of recorded measurements ended with the digit zero, whereas "without bias, 10%–20% of measurements are expected to end in zero" Therefore, addressing digit preference is a key issue for improving blood pressure measurement accuracy.


title: Blood pressure

text: Blood pressure levels in non-human mammals may vary depending on the species. Heart rate differs markedly, largely depending on the size of the animal (larger animals have slower heart rates). The giraffe has a distinctly high arterial pressure of about 190 mm Hg, enabling blood perfusion through the -long neck to the head. In other species subjected to orthostatic blood pressure, such as arboreal snakes, blood pressure is higher than in non-arboreal snakes. A heart near to the head (short heart-to-head distance) and a long tail with tight integument favor blood perfusion to the head.


title: Blood pressure

text: As in humans, blood pressure in animals differs by age, sex, time of day, and environmental circumstances: measurements made in laboratories or under anesthesia may not be representative of values under free-living conditions. Rats, mice, dogs and rabbits have been used extensively to study the regulation of blood pressure.


title: Blood pressure

text: Hypertension in cats and dogs is generally diagnosed if the blood pressure is greater than 150 mm Hg (systolic), although sight hounds have higher blood pressures than most other dog breeds; a systolic pressure greater than 180 mmHg is considered abnormal in these dogs.


title: Permian–Triassic extinction event

text: The Permian–Triassic (P–T, P–Tr) extinction event, also known as the End-Permian Extinction and colloquially as the Great Dying, formed the boundary between the Permian and Triassic geologic periods, as well as between the Paleozoic and Mesozoic eras, approximately 251.9 million years ago. It is the Earth's most severe known extinction event, with the extinction of 57% of biological families, 83% of genera, 81% of marine species and 70% of terrestrial vertebrate species. It was the largest known mass extinction of insects.


title: Permian–Triassic extinction event

text: The scientific consensus is that the main cause of extinction was the large amount of carbon dioxide emitted by the volcanic eruptions that created the Siberian Traps, which elevated global temperatures, and in the oceans led to widespread anoxia and acidification.<ref name="lava/coal fires"></ref> Proposed contributing factors include: the emission of much additional carbon dioxide from the thermal decomposition of hydrocarbon deposits, including oil and coal, triggered by the eruptions; and emissions of methane by novel methanogenic microorganisms, perhaps nourished by minerals dispersed in the eruptions.


title: Permian–Triassic extinction event

text: The speed of recovery from the extinction is disputed. Some scientists estimate that it took 10 million years (until the Middle Triassic), due both to the severity of the extinction and because grim conditions returned periodically for another 5 million years, causing further extinction events, such as the Smithian-Spathian boundary extinction. However, studies in Bear Lake County, near Paris, Idaho, and nearby sites in Idaho and Nevada showed a relatively quick rebound in a localized Early Triassic marine ecosystem, taking around 3 million years to recover, suggesting that the impact of the extinction may have been felt less severely in some areas than in others.


title: Permian–Triassic extinction event

text: Previously, it was thought that rock sequences spanning the Permian–Triassic boundary were too few and contained too many gaps for scientists to reliably determine its details. However, it is now possible to date the extinction with millennial precision. U–Pb zircon dates from five volcanic ash beds from the Global Stratotype Section and Point for the Permian–Triassic boundary at Meishan, China, establish a high-resolution age model for the extinction – allowing exploration of the links between global environmental perturbation, carbon cycle disruption, mass extinction, and recovery at millennial timescales.


title: Permian–Triassic extinction event

text: The extinction occurred between and years ago, a duration of 60 ± 48 thousand years. A large (approximately 0.9%), abrupt global decrease in the ratio of the stable isotope carbon-13 to that of carbon-12 coincides with this extinction, and is sometimes used to identify the Permian–Triassic boundary in rocks that are unsuitable for radiometric dating.


title: Permian–Triassic extinction event

text: Further evidence for environmental change around the P–Tr boundary suggests an rise in temperature, and an increase in levels by (for comparison, the concentration immediately before the Industrial Revolution was , and the amount today is about 415 ppm). There is also evidence of increased ultraviolet radiation reaching the earth, causing the mutation of plant spores.


title: Permian–Triassic extinction event

text: It has been suggested that the Permian–Triassic boundary is associated with a sharp increase in the abundance of marine and terrestrial fungi, caused by the sharp increase in the amount of dead plants and animals fed upon by the fungi. For a while this "fungal spike" was used by some paleontologists to identify the Permian–Triassic boundary in rocks that are unsuitable for radiometric dating or lack suitable index fossils, but even the proposers of the fungal spike hypothesis pointed out that "fungal spikes" may have been a repeating phenomenon created by the post-extinction ecosystem in the earliest Triassic. The very idea of a fungal spike has been criticized on several grounds, including: "Reduviasporonites", the most common supposed fungal spore, may be a fossilized alga; the spike did not appear worldwide; and in many places it did not fall on the Permian–Triassic boundary. The reduviasporonites may even represent a transition to a lake-dominated Triassic world rather than an earliest Triassic zone of death and decay in some terrestrial fossil beds. Newer chemical evidence agrees better with a fungal origin for "Reduviasporonites", diluting these critiques.


title: Permian–Triassic extinction event

text: Uncertainty exists regarding the duration of the overall extinction and about the timing and duration of various groups' extinctions within the greater process. Some evidence suggests that there were multiple extinction pulses or that the extinction was spread out over a few million years, with a sharp peak in the last million years of the Permian. Statistical analyses of some highly fossiliferous strata in Meishan, Zhejiang Province in southeastern China, suggest that the main extinction was clustered around one peak. Recent research shows that different groups became extinct at different times; for example, while difficult to date absolutely, ostracod and brachiopod extinctions were separated by 670,000 to 1.17 million years. In a well-preserved sequence in east Greenland, the decline of animals is concentrated in a period 10,000 to 60,000 years long, with plants taking an additional several hundred thousand years to show the full impact of the event.


title: Permian–Triassic extinction event

text: An older theory, still supported in some recent papers, is that there were two major extinction pulses 9.4 million years apart, separated by a period of extinctions well above the background level, and that the final extinction killed off only about 80% of marine species alive at that time while the other losses occurred during the first pulse or the interval between pulses. According to this theory one of these extinction pulses occurred at the end of the Guadalupian epoch of the Permian. For example, all dinocephalian genera died out at the end of the Guadalupian, as did the Verbeekinidae, a family of large-size fusuline foraminifera. The impact of the end-Guadalupian extinction on marine organisms appears to have varied between locations and between taxonomic groups – brachiopods and corals had severe losses.


title: Permian–Triassic extinction event

text: Studies of the timing and causes of the Permian-Triassic extinction are complicated by the often-overlooked Capitanian extinction (also called the "Guadalupian extinction"), just one of perhaps two mass extinctions in the late Permian that closely preceded the Permian-Triassic event. In short, when the Permian-Triassic starts it is difficult to know whether the end-Capitanian had finished, depending on the factor considered. Some of the extinctions dated to the Permian-Triassic boundary have recently been redated to the end-Capitanian. Further, it is unclear whether some species who survived the prior extinction(s) had recovered well enough for their final demise in the Permian-Triassic event to be considered separate from Capitanian event. A minority point of view considers the sequence of environmental disasters to have effectively constituted a single, prolonged extinction event, perhaps depending on which species is considered.


title: Permian–Triassic extinction event

text: Marine invertebrates suffered the greatest losses during the P–Tr extinction. Evidence of this was found in samples from south China sections at the P–Tr boundary. Here, 286 out of 329 marine invertebrate genera disappear within the final two sedimentary zones containing conodonts from the Permian. The decrease in diversity was probably caused by a sharp increase in extinctions, rather than a decrease in speciation.


title: Permian–Triassic extinction event

text: The extinction primarily affected organisms with calcium carbonate skeletons, especially those reliant on stable CO levels to produce their skeletons. These organisms were susceptible to the effects of the ocean acidification that resulted from increased atmospheric CO.


title: Permian–Triassic extinction event

text: Among benthic organisms the extinction event multiplied background extinction rates, and therefore caused maximum species loss to taxa that had a high background extinction rate (by implication, taxa with a high turnover). The extinction rate of marine organisms was catastrophic. Bioturbators were extremely severely affected, as evidenced by the loss of the sedimentary mixed layer in many marine facies during the end-Permian extinction.


title: Permian–Triassic extinction event

text: Surviving marine invertebrate groups included articulate brachiopods (those with a hinge), which had undergone a slow decline in numbers since the P–Tr extinction; the Ceratitida order of ammonites; and crinoids ("sea lilies"), which very nearly became extinct but later became abundant and diverse. The groups with the highest survival rates generally had active control of circulation, elaborate gas exchange mechanisms, and light calcification; more heavily calcified organisms with simpler breathing apparatuses suffered the greatest loss of species diversity. In the case of the brachiopods, at least, surviving taxa were generally small, rare members of a formerly diverse community.


title: Permian–Triassic extinction event

text: The ammonoids, which had been in a long-term decline for the 30 million years since the Roadian (middle Permian), suffered a selective extinction pulse 10 million years before the main event, at the end of the Capitanian stage. In this preliminary extinction, which greatly reduced disparity, or the range of different ecological guilds, environmental factors were apparently responsible. Diversity and disparity fell further until the P–Tr boundary; the extinction here (P–Tr) was non-selective, consistent with a catastrophic initiator. During the Triassic, diversity rose rapidly, but disparity remained low. The range of morphospace occupied by the ammonoids, that is, their range of possible forms, shapes or structures, became more restricted as the Permian progressed. A few million years into the Triassic, the original range of ammonoid structures was once again reoccupied, but the parameters were now shared differently among clades.


title: Permian–Triassic extinction event

text: The Permian had great diversity in insect and other invertebrate species, including the largest insects ever to have existed. The end-Permian is the largest known mass extinction of insects; according to some sources, it may well be the "only" mass extinction to significantly affect insect diversity. Eight or nine insect orders became extinct and ten more were greatly reduced in diversity. Palaeodictyopteroids (insects with piercing and sucking mouthparts) began to decline during the mid-Permian; these extinctions have been linked to a change in flora. The greatest decline occurred in the Late Permian and was probably not directly caused by weather-related floral transitions.


title: Permian–Triassic extinction event

text: Most fossil insect groups found after the Permian–Triassic boundary differ significantly from those before: Of Paleozoic insect groups, only the Glosselytrodea, Miomoptera, and Protorthoptera have been discovered in deposits from after the extinction. The caloneurodeans, monurans, paleodictyopteroids, protelytropterans, and protodonates became extinct by the end of the Permian. Though Triassic insects are very different from those of the Permian, a gap in the insect fossil record spans approximately 15 million years from the late Permian to early Triassic. In well-documented Late Triassic deposits, fossils overwhelmingly consist of modern fossil insect groups.


title: Permian–Triassic extinction event

text: The geological record of terrestrial plants is sparse and based mostly on pollen and spore studies. Plants are relatively immune to mass extinction, with the impact of all the major mass extinctions "insignificant" at a family level. Even the reduction observed in species diversity (of 50%) may be mostly due to taphonomic processes. However, a massive rearrangement of ecosystems does occur, with plant abundances and distributions changing profoundly and all the forests virtually disappearing; the Palaeozoic flora scarcely survived this extinction.


title: Permian–Triassic extinction event

text: At the P–Tr boundary, the dominant floral groups changed, with many groups of land plants entering abrupt decline, such as "Cordaites" (gymnosperms) and "Glossopteris" (seed ferns). Dominant gymnosperm genera were replaced post-boundary by lycophytesextant lycophytes are recolonizers of disturbed areas.


title: Permian–Triassic extinction event

text: Palynological or pollen studies from East Greenland of sedimentary rock strata laid down during the extinction period indicate dense gymnosperm woodlands before the event. At the same time that marine invertebrate macrofauna declined, these large woodlands died out and were followed by a rise in diversity of smaller herbaceous plants including Lycopodiophyta, both Selaginellales and Isoetales. Later, other groups of gymnosperms again become dominant but again suffered major die-offs. These cyclical flora shifts occurred a few times over the course of the extinction period and afterward. These fluctuations of the dominant flora between woody and herbaceous taxa indicate chronic environmental stress resulting in a loss of most large woodland plant species. The successions and extinctions of plant communities do not coincide with the shift in values but occurred many years after. The recovery of gymnosperm forests took 4–5 million years.


title: Permian–Triassic extinction event

text: In China, the subtropical Cathaysian gigantopterid dominated rainforests abruptly collapsed, and were replaced by low-lying herbaceous vegetation dominated by the isoetalean "Tomiostrobus."


title: Permian–Triassic extinction event

text: In the Kuznetsk Basin, the aridity-induced extinction of the regions's humid-adapted forest flora dominated by cordaites occurred approximately 252.76 Ma, around 820,000 years before the end-Permian extinction in South China, suggesting that the end-Permian biotic catastrophe may have started earlier on land and that the ecological crisis may have been more gradual and asynchronous on land compared to its more abrupt onset in the marine realm.


title: Permian–Triassic extinction event

text: No coal deposits are known from the Early Triassic, and those in the Middle Triassic are thin and low-grade. This "coal gap" has been explained in many ways. It has been suggested that new, more aggressive fungi, insects, and vertebrates evolved and killed vast numbers of trees. These decomposers themselves suffered heavy losses of species during the extinction and are not considered a likely cause of the coal gap. It could simply be that all coal-forming plants were rendered extinct by the P–Tr extinction and that it took 10 million years for a new suite of plants to adapt to the moist, acid conditions of peat bogs. Abiotic factors (factors not caused by organisms), such as decreased rainfall or increased input of clastic sediments, may also be to blame.


title: Permian–Triassic extinction event

text: On the other hand, the lack of coal may simply reflect the scarcity of all known sediments from the Early Triassic. Coal-producing ecosystems, rather than disappearing, may have moved to areas where we have no sedimentary record for the Early Triassic. For example, in eastern Australia a cold climate had been the norm for a long period, with a peat mire ecosystem adapted to these conditions. Approximately 95% of these peat-producing plants went "locally" extinct at the P–Tr boundary; coal deposits in Australia and Antarctica disappear significantly "before" the P–Tr boundary.


title: Permian–Triassic extinction event

text: There is enough evidence to indicate that over two thirds of terrestrial labyrinthodont amphibians, sauropsid ("reptile") and therapsid ("proto-mammal") taxa became extinct. Large herbivores suffered the heaviest losses.


title: Permian–Triassic extinction event

text: All Permian anapsid reptiles died out except the procolophonids (although testudines have "morphologically"-anapsid skulls, they are now thought to have separately evolved from diapsid ancestors). Pelycosaurs died out before the end of the Permian. Too few Permian diapsid fossils have been found to support any conclusion about the effect of the Permian extinction on diapsids (the "reptile" group from which lizards, snakes, crocodilians, and dinosaurs (including birds) evolved).


title: Permian–Triassic extinction event

text: The groups that survived suffered extremely heavy losses of species and some terrestrial vertebrate groups very nearly became extinct at the end of the Permian. Some of the surviving groups did not persist for long past this period, but others that barely survived went on to produce diverse and long-lasting lineages. However, it took 30million years for the terrestrial vertebrate fauna to fully recover both numerically and ecologically.


title: Permian–Triassic extinction event

text: It is difficult to analyze extinction and survival rates of land organisms in detail because few terrestrial fossil beds span the Permian–Triassic boundary. The best-known record of vertebrate changes across the Permian–Triassic boundary occurs in the Karoo Supergroup of South Africa, but statistical analyses have so far not produced clear conclusions.


title: Permian–Triassic extinction event

text: In the wake of the extinction event, the ecological structure of present-day biosphere evolved from the stock of surviving taxa. In the sea, the "Modern Evolutionary Fauna" became dominant over elements of the "Palaeozoic Evolutionary Fauna". Typical taxa of shelly benthic faunas were now bivalves, snails, sea urchins and Malacostraca, whereas bony fishes and marine reptiles diversified in the pelagic zone. On land, dinosaurs and mammals arose in the course of the Triassic. The profound change in the taxonomic composition was partly a result of the selectivity of the extinction event, which affected some taxa (e.g., brachiopods) more severely than others (e.g., bivalves). However, recovery was also differential between taxa. Some survivors became extinct some million years after the extinction event without having rediversified (dead clade walking, e.g. the snail family Bellerophontidae), whereas others rose to dominance over geologic times (e.g., bivalves).


title: Permian–Triassic extinction event

text: Marine post-extinction faunas were mostly species-poor and dominated by few disaster species such as the bivalves "Claraia" and "Unionites". Seafloor communities maintained a comparatively low diversity until the end of the Early Triassic, approximately 4 million years after the extinction event. This slow recovery stands in remarkable contrast with the quick recovery seen in nektonic organisms such as ammonoids, which exceeded pre-extinction diversities already two million years after the crisis. The relative delay in the recovery of benthic organisms has been attributed to widespread anoxia, but high abundances of benthic species contradict this explanation. More recent work suggests that the pace of recovery was intrinsically driven by the intensity of competition among species, which drives rates of niche differentiation and speciation. Accordingly, low levels of interspecific competition in seafloor communities that are dominated by primary consumers correspond to slow rates of diversification and high levels of interspecific competition among nektonic secondary and tertiary consumers to high diversification rates. Other studies point to the recurrent episodes of extremely hot climatic conditions during the Early Triassic for the delayed recovery of oceanic life. Whereas most marine communities were fully recovered by the Middle Triassic, global marine diversity reached pre-extinction values no earlier than the Middle Jurassic, approximately 75 million years after the extinction event.


title: Permian–Triassic extinction event

text: Prior to the extinction, about two-thirds of marine animals were sessile and attached to the seafloor. During the Mesozoic, only about half of the marine animals were sessile while the rest were free-living. Analysis of marine fossils from the period indicated a decrease in the abundance of sessile epifaunal suspension feeders such as brachiopods and sea lilies and an increase in more complex mobile species such as snails, sea urchins and crabs.


title: Permian–Triassic extinction event

text: Before the Permian mass extinction event, both complex and simple marine ecosystems were equally common. After the recovery from the mass extinction, the complex communities outnumbered the simple communities by nearly three to one, and the increase in predation pressure led to the Mesozoic Marine Revolution.


title: Permian–Triassic extinction event

text: Bivalves were fairly rare before the P–Tr extinction but became numerous and diverse in the Triassic, taking over niches that were filled primarily by brachiopods before the mass extinction event, and one group, the rudist clams, became the Mesozoic's main reef-builders. Some researchers think much of the change happened in the 5 million years between the two major extinction pulses.


title: Permian–Triassic extinction event

text: Crinoids ("sea lilies") suffered a selective extinction, resulting in a decrease in the variety of their forms. Their ensuing adaptive radiation was brisk, and resulted in forms possessing flexible arms becoming widespread; motility, predominantly a response to predation pressure, also became far more prevalent.


title: Permian–Triassic extinction event

text: Microbial-metazoan reefs dominated surviving communities in the immediate wake of the mass extinction. Metazoan-built reefs reemerged during the Olenekian, mainly being composed of sponge biostrome and bivalve builups. ""Tubiphytes""-dominated reefs appeared at the end of the Olenekian, representing the earliest platform-margin reefs of the Triassic, though they did not become abundant until the late Anisian, when reefs' species richness increased. The first scleractinian corals appear in the late Anisian as well, although they would not become the dominant reef builders until the end of the Triassic period.


title: Permian–Triassic extinction event

text: "Lystrosaurus", a pig-sized herbivorous dicynodont therapsid, constituted as much as 90% of some earliest Triassic land vertebrate fauna. Smaller carnivorous cynodont therapsids also survived, including the ancestors of mammals. In the Karoo region of southern Africa, the therocephalians "Tetracynodon", "Moschorhinus" and "Ictidosuchoides" survived, but do not appear to have been abundant in the Triassic. In North China, tetrapod body and ichnofossils are extremely rare in Induan facies, but become more abundant in the Olenekian and Anisian, showing a biotic recovery of tetrapods synchronous with the decreasing aridity during the Olenekian and Anisian.


title: Permian–Triassic extinction event

text: Archosaurs (which included the ancestors of dinosaurs and crocodilians) were initially rarer than therapsids, but they began to displace therapsids in the mid-Triassic. In the mid to late Triassic, the dinosaurs evolved from one group of archosaurs, and went on to dominate terrestrial ecosystems during the Jurassic and Cretaceous. This "Triassic Takeover" may have contributed to the evolution of mammals by forcing the surviving therapsids and their mammaliform successors to live as small, mainly nocturnal insectivores; nocturnal life probably forced at least the mammaliforms to develop fur, better hearing and higher metabolic rates, while losing part of the differential color-sensitive retinal receptors reptilians and birds preserved. The archosaur dominance would end again due to the Cretaceous–Paleogene extinction event, after which both birds (only extant dinosaurs) and mammals (only extant synapsids) would diversify and share the world.


title: Permian–Triassic extinction event

text: Some temnospondyl amphibians made a relatively quick recovery, in spite of nearly becoming extinct. "Mastodonsaurus" and trematosaurians were the main aquatic and semiaquatic predators during most of the Triassic, some preying on tetrapods and others on fish.


title: Permian–Triassic extinction event

text: Land vertebrates took an unusually long time to recover from the P–Tr extinction; Palaeontologist Michael Benton estimated the recovery was not complete until after the extinction, i.e. not until the Late Triassic, when the first dinosaurs had risen from bipedal archosaurian ancestors and the first mammals from small cynodont ancestors.


title: Permian–Triassic extinction event

text: Pinpointing the exact causes of the Permian–Triassic extinction event is difficult, mostly because it occurred over 250 million years ago, and since then much of the evidence that would have pointed to the cause has been destroyed or is concealed deep within the Earth under many layers of rock. The sea floor is completely recycled over around 200 million years by the ongoing process of plate tectonics and seafloor spreading, leaving no useful indications beneath the ocean.


title: Permian–Triassic extinction event

text: Yet, scientists have gathered significant evidence for causes, and several mechanisms have been proposed. The proposals include both catastrophic and gradual processes (similar to those theorized for the Cretaceous–Paleogene extinction event).


title: Permian–Triassic extinction event

text: Any hypothesis about the cause must explain the selectivity of the event, which affected organisms with calcium carbonate skeletons most severely; the long period (4 to 6 million years) before recovery started, and the minimal extent of biological mineralization (despite inorganic carbonates being deposited) once the recovery began.


title: Permian–Triassic extinction event

text: The final stages of the Permian had two flood basalt events. A smaller one, the Emeishan Traps in China, occurred at the same time as the end-Guadalupian extinction pulse, in an area close to the equator at the time. The flood basalt eruptions that produced the Siberian Traps constituted one of the largest known volcanic events on Earth and covered over with lava. The date of the Siberian Traps eruptions and the extinction event are in good agreement. The Siberian Traps are underlain by thick sequences of Early-Mid Paleozoic aged carbonate and evaporite deposits, as well as Carboniferous-Permian aged coal bearing clastic rocks. When heated, such as by igneous intrusions, these rocks are capable of emitting large amounts of greenhouse and toxic gases. The unique setting of the Siberian Traps over these deposits is likely the reason for the severity of the extinction.


title: Permian–Triassic extinction event

text: The Emeishan and Siberian Traps eruptions may have caused dust clouds and acid aerosols, which would have blocked out sunlight and thus disrupted photosynthesis both on land and in the photic zone of the ocean, causing food chains to collapse. The eruptions may also have caused acid rain as the aerosols washed out of the atmosphere. That may have killed land plants and mollusks and planktonic organisms which had calcium carbonate shells. The eruptions would also have emitted carbon dioxide, causing global warming. When all of the dust clouds and aerosols washed out of the atmosphere, the excess carbon dioxide would have remained and the warming would have proceeded without any mitigating effects.


title: Permian–Triassic extinction event

text: The Siberian Traps had unusual features that made them even more dangerous. Pure flood basalts produce fluid, low-viscosity lava, and do not hurl debris into the atmosphere. It appears, however, that 20% of the output of the Siberian Traps eruptions was pyroclastic (consisted of ash and other debris thrown high into the atmosphere), increasing the short-term cooling effect. The basalt lava erupted or intruded into carbonate rocks and into sediments that were in the process of forming large coal beds, both of which would have emitted large amounts of carbon dioxide, leading to stronger global warming after the dust and aerosols settled. In addition, these volcanic eruptions released significant quantities of toxic mercury into the atmosphere and ocean, further contributing to large scale die-offs of terrestrial and marine life.


title: Permian–Triassic extinction event

text: In January 2011, a team, led by Stephen Grasby of the Geological Survey of Canada – Calgary, reported evidence that volcanism caused massive coal beds to ignite, possibly releasing more than 3 trillion tons of carbon. The team found ash deposits in deep rock layers near what is now the Buchanan Lake Formation. According to their article, "coal ash dispersed by the explosive Siberian Trap eruption would be expected to have an associated release of toxic elements in impacted water bodies where fly ash slurries developed. ... Mafic megascale eruptions are long-lived events that would allow significant build-up of global ash clouds." In a statement, Grasby said, "In addition to these volcanoes causing fires through coal, the ash it spewed was highly toxic and was released in the land and water, potentially contributing to the worst extinction event in earth history." In 2013, a team led by Q.Y. Yang reported the total amounts of important volatiles emitted from the Siberian Traps are


title: Permian–Triassic extinction event

text: The data support a popular notion that the end-Permian mass extinction on the Earth was caused by the emission of enormous amounts of volatiles from the Siberian Traps into the atmosphere.


title: Permian–Triassic extinction event

text: In 2015, evidence and a timeline indicated the extinction was caused by events in the large igneous province of the Siberian Traps. Carbon dioxide levels prior to and after the eruptions are poorly constrained, but may have jumped from between 500 and 4000  prior to the extinction event to around 8000  after the extinction.


title: Permian–Triassic extinction event

text: In 2020 scientists reconstructed the mechanisms that led to the extinction event in a biogeochemical model, showed the consequences of the greenhouse effect on the marine environment and reported that the mass extinction can be traced back to volcanic CO emissions. Further evidence – based on paired coronene-mercury spikes – for a volcanic combustion cause of the mass extinction was published in 2020.


title: Permian–Triassic extinction event

text: Methane clathrates, also known as methane hydrates, consist of methane molecules trapped in cages of water molecules. The methane, produced by methanogens (microscopic single-celled organisms), has a about 6.0% below normal ( −6.0%). At the right combination of pressure and temperature, the methane is trapped in clathrates fairly close to the surface of permafrost and, in much larger quantities, on continental shelves and the deeper seabed close to them. Oceanic methane hydrates are usually found buried in sediments where the seawater is at least deep. They can be found up to about below the sea floor, but usually only about below the sea floor.


title: Permian–Triassic extinction event

text: The release of methane from the clathrates has been considered as a cause because scientists have found worldwide evidence of a swift decrease of about 1% in the in carbonate rocks from the end-Permian. This is the first, largest, and most rapid of a series of negative and positive excursions (decreases and increases in ) that continues until the isotope ratio abruptly stabilised in the middle Triassic, followed soon afterwards by the recovery of calcifying life forms (organisms that use calcium carbonate to build hard parts such as shells). While a variety of factors may have contributed to this drop in the , a 2002 review found most of them to be insufficient to account fully for the observed amount:


title: Permian–Triassic extinction event

text: Other hypotheses include mass oceanic poisoning, releasing vast amounts of CO, and a long-term reorganisation of the global carbon cycle.