Megalodon sharks, terror of the oceans, became extinct 2.6 million years ago and whales grew : SCIENCE : Tech Times Megalodon sharks, terror of the oceans, became extinct 2.6 million years ago and whales grew 25 October 2014, 9:38 pm EDT By Jim Algar Tech Times Whales only began to evolve to their current massive sizes with the disappearance of a fearsome ancient predator, researchers suggest. Whales may have been a preferred prey of prehistoric, 50-foot shark known as Medalodon. ( Karen Carr | Wikipedia | Creative Commons ) Advertisement Whales may have evolved to their current massive sizes only because one of their most fearsome predators, the largest shark species known to science, went extinct, researchers say. Primitive baleen whales, smaller than their modern-day counterparts, were a likely prey of Megalodon, a prehistoric 50-foot-long predator something like a jumbo-sized Great White, the scientists say.

In a study published in the journal PLOS One, the researchers put the date for Megalodon's extinction at about 2.6 million years ago, after which baleen whales as a group began to evolve and grow to the giant sizes seen today. The group includes the blue whale, the largest animal on Earth that can reach lengths of 100 feet. While the researchers acknowledge there is no definite evidence that Megalodon preferred baleen whales as prey, they note that ancient whale fossils are often discovered in company with Megalodon teeth. If the whales were in fact a feature of Megalodon diets, then the extinction of the ancient mega-shark may have allowed them to flourish and evolve, researchers say. "When we found out when that [extinction] happened, we noticed it coincided with the [evolution] pattern mentioned in whales," says study co-author Catalina Pimiento from the Florida Museum of Natural History. "Now we need to find out if one event -- Megalodon's extinction -- caused the other -- evolution of gigantism in whales." The fossil record for Megalodon is spotty with a number of gaps, making an accurate determination of when it went extinct difficult, researchers say.

Pimiento and research colleagues from the University of Florida placed 42 known Megalodon fossils in a database, assigning each one an upper and lower date estimate in an attempt to narrow the gaps. "Based on the distribution of those gaps and how those gaps change, it will then infer the point in time where that species can be considered to be extinct," researcher Chris Clements said. That yielded a 99.9 percent certainty the mega-shark species was extinct by 2.6 million years ago, the researchers said. That's strong evidence refuting the claims made by some people that Megalodon may still be alive and lurking in the world's ocean's today, a claim featuring prominently in some programs aired as part of the Discovery Channel's "Shark Week." Most shark experts say they've confident the giant species is long gone. "If a 50-foot-long predator that fed on surface animals and lived in coastal environments were still around, someone would have found evidence of this by now," shark enthusiast David Shiffman says .

Megalodon Became Extinct 2.6 Million Years Ago | myFOSSIL Megalodon Became Extinct 2.6 Million Years Ago by Catalina Pimiento, Doctoral Student, Florida Museum of Natural History, University of Florida My most recent study on Megalodon, the largest shark that ever lived, was published in the open access journal PLoS ONE last month. This work was the result of a collaborative project with Chris Clements, an expert in mathematical methods that calculate times of extinction, and is part of a larger project where I intend to reconstruct the extinction of this giant shark. Catalina Pimiento photo © Jeff Gage Why do I study the extinction of Megalodon? Megalodon is a very important species because it was an apex predator. Apex predators are animals that are at the top of the food chain, and have no threats from other predators. These animals maintain ecosystem stability as they control the populations of their prey. Therefore, their removal produces cascading effects (affecting all trophic levels) with catastrophic effects. Given its importance, the extinction of apex predators has been extensively studied by modern ecology. However, the temporal and spatial scales of these studies are usually limited.

Consequently, what we know about the extinction of apex predators is based on population declines or local extirpations, as opposed to actual extinctions. Hence, the study of the extinction of the Megalodon has the potential to offer a broader perspective, not just because it is a giant and cosmopolitan species, but because it has an extensive fossil record spanning for millions of years. That is why I have been studying the extinction of Megalodon for the last several years. But in order to better understand the extinction of this animal, the first step is to know when it happened. The extinction of species is something we cannot observe directly. Although some scientists use the date of the most recent fossil as a proxy for their extinction time, the fact is that species can survive long after the last time they were recorded. To calculate the most likely extinction date, several methods based on their last records (or sightings) have been developed. The benefits of scientific conferences Last year, I had the privilege to attend an international ecology conference (INTECOL) in London. There, I attended a talk on an experimental study that tested the effectiveness of the methods that have been proposed to calculate dates of extinction.

Given that I work with the largest shark that ever lived, it was a bit ironic that I found a talk about protists so interesting. In any case, I decided to invite the speaker (Chris Clements) to the talk I was giving the next day. In my talk, I mentioned my studies on the evolution of body size of Megalodon, and my intentions to do a meta-analysis of the fossil record to reconstruct its extinction. Chris and I met later that day and decided to study the extinction time of Megalodon combining the methods he works with, and my ideas and results of the meta-analysis. The study We started by collecting the most recent records of the species. For that, we used the Paleobiology Database (PaleoBioDB) as a platform. As this database was incomplete (for Megalodon), we collected all articles reporting the occurrence of species, and added them to the PaleoBioDB. All these data are available to the public. Once we constructed the dataset (# 20 in the PaleoBioDB), we evaluated each record to make sure to include in the analysis only those with sufficient evidence on the age of the fossils.

With this subset of data, we used the Optimal Linear Estimation model (OLE), which has been used before to calculate the extinction time of the Dodo. This method calculates the time of extinction based on the distribution of the most recent records. Given that in our case, the records do not have an absolute date, but instead, they span in a range of time, we re-sampled the age of each record 10,000 times from the highest to the lowest age. The results suggest that the Megalodon became extinct around 2.6 million years ago. Since it has been suggested this species interacted with marine mammals, we proceeded to compare the results with the known evolution and diversification patterns of cetaceans. What a surprise! We noticed that our calculated extinction time for Megalodon coincides with the Pliocene and Pleistocene boundary. During the Pleistocene, modern baleen whales reached giant sizes. Therefore, in our study we suggest that the size, and therefore the ecological role of modern whales, was established once the world’s largest shark, Megalodon, became extinct.

For now, our study only provides the time of the extinction and recognizes the coincidence with the evolution of gigantism in modern whales. Knowing if an event caused another is our next step. Further reading: Megalodon shark became extinct 2.6 million years ago Megalodon shark became extinct 2.6 million years ago October 23, 2014 by Stephenie Livingston University of Florida doctoral candidate Catalina Pimiento, pictured here measuring a megalodon shark tooth at the Smithsonian Tropical Research Institute in Panama, is lead author of a PLOS ONE study appearing online today (Oct. 22, 2014) establishing megalodon became extinct 2.6 million years ago. Credit: Jeff Gage (Phys.org) —A new University of Florida study dismisses claims that megalodon is still alive by determining a date of extinction for the largest predatory shark to ever live. Researchers from UF and the University of Zurich hope the study appearing online today in the journal PLOS ONE showing the species became extinct 2.6 million years ago will clarify public confusion. The study may also one day help scientists better understand the potential widespread effects of losing the planet's top predators, said lead author Catalina Pimiento.

"I was drawn to the study of Carcharocles megalodon's extinction because it is fundamental to know when species became extinct to then begin to understand the causes and consequences of such an event," said Pimiento, a doctoral candidate at the Florida Museum of Natural History on the UF campus. "I also think people who are interested in this animal deserve to know what the scientific evidence shows, especially following Discovery Channel specials that implied megalodon may still be alive." The study represents the first phase of Pimiento's ongoing reconstruction of megalodon's extinction. As modern top predators, especially large sharks, are significantly declining worldwide due to the current biodiversity crisis, Pimiento said this study serves as the basis to better understand the consequences of these changes. "When you remove large sharks, then small sharks are very abundant and they consume more of the invertebrates that we humans eat," Pimiento said. "Recent estimations show that large-bodied, shallow-water species of sharks are at greatest risk among marine animals, and the overall risk of shark extinction is substantially higher than for most other vertebrates." Pimiento plans to further investigate possible correlations between changes in megalodon's distribution and the evolutionary trends of marine mammals, such as whales and other sharks.

"When we calculated the time of megalodon's extinction, we noticed that the modern function and gigantic sizes of filter feeder whales became established around that time," Pimiento said. "Future research will investigate if megalodon's extinction played a part in the evolution of these new classes of whales." The slowly unraveling details of megalodon's extinction and various aspects of its natural history have consumed Pimiento's research for the past six years, including ongoing analysis of megalodon's body size and a 2010 PLOS ONE study that proposed Panama served as a nursery habitat for the species. For the new study, researchers used databases and scientific literature of the most recent megalodon records and calculated the extinction using a novel mathematical model proven reliable in recent experimental testing by study co-author Christopher F. Clements with the Institute of Evolutionary Biology and Environmental Studies at the University of Zurich. Vertebrate paleontologist Jorge Velez-Juarbe with the Natural History Museum of Los Angeles County said the study will not only serve as a key reference for debunking the myth that megalodon still exists, but its novel methods will influence the future of scientific research of extinct animals and plants.

"The methodology that the authors used had only been previously employed to determine extinction dates in historical times, such as to estimate the extinction date of the dodo bird," Velez-Juarbe said. "In this work, scientists applied that same methodology to determine the extinction of an organism millions of years ago, instead of hundreds. It's a new tool that paleo biologists didn't have, or rather had not thought of using before." Giant Magalodon Shark Became Extinct 2.6 Million Years Ago James Fenner According to University of Florida researchers, the giant megalodon shark became extinct around 2.6 million years ago. The researchers, who published their findings in the journal PLOS ONE, hope the new extinction date will dispel confusion surrounding the species’ demise, with many members of the public under the misapprehension that the monster-sized creature still exists today. Lead author Catalina Pimiento, who is candidate at the Florida Museum of Natural History, said it was of critical importance to know when the species became extinct to appreciate the impact of such an event.

“… people who are interested in this animal deserve to know what the scientific evidence shows, especially following Discovery Channel specials that implied megalodon may still be alive,” added Pimiento. Megalodon (Carcharocles megalodon) sharks used to roam the oceans from the Pliocene to the Pleistocene, and represented one of the most powerful, vertebrate predators to have ever existed. Fossilized remains show that the shark could grow to become 60-foot-long. The population numbers of the behemoth shark began to dwindle right around the time when baleen whales started to increase in size. It comes as no surprise that the baleen whales then began to show greater dominance, since, without the megalodon sharks to keep their numbers in check, they faced fewer threats from predators. It has been somewhat difficult to determine when the megalodon went extinct, since its fossil record remains relatively poor. However, more recently, Pimiento and colleagues set about performing literature searches for the latest megalodon records. Using over 40 recent fossils from the Paleobiology Database, the team applied Optimal Linear Estimation to approximate the species’ extinction date.

Speaking to Live Science , University of Zurich research assistant Chris Clements said around 10,000 extinction estimates were generated from the simulations they ran on the fossil collection. “We get 10,000 estimates for the time the species has gone extinct by, and then we look at the distribution of those estimates through time,” explained Clements. After looking at where most of the estimates were clustered, the group’s findings suggest the megalodon shark became extinct some 2.6 million years ago. The study, entitled When Did Carcharocles megalodon Become Extinct? A New Analysis of the Fossil Record, was published in the Oct. 22 issue of the Journal PLOS ONE . Megalodon Went Extinct 2.6 Million Years Ago; What Will Happen If The Same Happens To Modern Species? : Science/Health : Headlines & Global News Advertisement Megalodon Went Extinct 2.6 Million Years Ago; What Will Happen If The Same Happens To Modern Species? By Oct 26, 2014 08:09 PM EDT The Megalodon went extinct about 2.6 million years ago.

Advertisement New research suggests the megalodon shark became extinct around 2.6 million years ago, squashing claims that it is still alive. The shark was the largest to ever live, and studying its existence could provide insight into potential effect of the loss of the world's larger predators, the University of Florida reported. "I was drawn to the study of Carcharocles megalodon's extinction because it is fundamental to know when species became extinct to then begin to understand the causes and consequences of such an event," said lead author Catalina, a doctoral candidate at the Florida Museum of Natural History on the UF campus. "I also think people who are interested in this animal deserve to know what the scientific evidence shows, especially following Discovery Channel specials that implied megalodon may still be alive." Modern large predators such as sharks are rapidly declining, and these findings could help measure the related consequences imposed on the ecosystem. "When you remove large sharks, then small sharks are very abundant and they consume more of the invertebrates that we humans eat," Pimiento said.

"Recent estimations show that large-bodied, shallow-water species of sharks are at greatest risk among marine animals, and the overall risk of shark extinction is substantially higher than for most other vertebrates." When the research team calculated the time of the megaladon's extinction, they found giant feeder whales became established around the same time; in the future they plan to look at if the ecological changes caused the whales to evolve. To make their findings the researchers used databases and scientific literature of the most recent megalodon records and used a mathematical model to determine when they became extinct. "The methodology that the authors used had only been previously employed to determine extinction dates in historical times, such as to estimate the extinction date of the dodo bird," Jorge Velez-Juarbe with the Natural History Museum of Los Angeles County said. "In this work, scientists applied that same methodology to determine the extinction of an organism millions of years ago, instead of hundreds. It's a new tool that paleo biologists didn't have, or rather had not thought of using before." The findings were published Oct. 22 in the journal PLOS ONE. © 2016 HNGN, All rights reserved. Do not reproduce without permission.

UF Study: Megalodon Became Extinct 2.6 Million Years Ago | By Space Coast Daily // October 23, 2014 Loading the player ... ABOVE VIDEO: Megalodon, meaning “big tooth,” is an extinct species of shark that lived approximately 28 to 1.5 million years ago, during the Cenozoic Era. GAINESVILLE, FLORIDA — A new University of Florida study dismisses claims that Megalodon is still alive by determining a date of extinction for the largest predatory shark to ever live. Related Story: SHARK WATCH: Megalodon Giant Shark Documentary Researchers from UF and the University of Zurich hope the study appearing online today in the journal PLOS ONE showing the species became extinct 2.6 million years ago will clarify public confusion. The study may also one day help scientists better understand the potential widespread effects of losing the planet’s top predators, said lead author Catalina Pimiento. University of Florida doctoral candidate Catalina Pimiento, pictured here measuring a megalodon shark tooth at the Smithsonian Tropical Research Institute in Panama, is lead author of a PLOS ONE study appearing online today (Oct.

22, 2014) establishing megalodon became extinct 2.6 million years ago. (Florida Museum of Natural History photo by Jeff Gage) “I was drawn to the study of Carcharocles megalodon’s extinction because it is fundamental to know when species became extinct to then begin to understand the causes and consequences of such an event,” said Pimiento, a doctoral candidate at the Florida Museum of Natural History on the UF campus. “I also think people who are interested in this animal deserve to know what the scientific evidence shows, especially following Discovery Channel specials that implied megalodon may still be alive.” The study represents the first phase of Pimiento’s ongoing reconstruction of megalodon’s extinction. As modern top predators, especially large sharks, are significantly declining worldwide due to the current biodiversity crisis, Pimiento said this study serves as the basis to better understand the consequences of these changes. “When you remove large sharks, then small sharks are very abundant and they consume more of the invertebrates that we humans eat,” Pimiento said.

“Recent estimations show that large-bodied, shallow-water species of sharks are at greatest risk among marine animals, and the overall risk of shark extinction is substantially higher than for most other vertebrates.” Pimiento plans to further investigate possible correlations between changes in megalodon’s distribution and the evolutionary trends of marine mammals, such as whales and other sharks. “When we calculated the time of megalodon’s extinction, we noticed that the modern function and gigantic sizes of filter feeder whales became established around that time,” Pimiento said. “Future research will investigate if megalodon’s extinction played a part in the evolution of these new classes of whales.” The slowly unraveling details of megalodon’s extinction and various aspects of its natural history have consumed Pimiento’s research for the past six years, including ongoing analysis of megalodon’s body size and a 2010 PLOS ONE study that proposed Panama served as a nursery habitat for the species. Related Story: Could a Prehistoric, 60-Foot Shark Still Exist? For the new study, researchers used databases and scientific literature of the most recent megalodon records and calculated the extinction using a novel mathematical model proven reliable in recent experimental testing by study co-author Christopher F.

Clements with the Institute of Evolutionary Biology and Environmental Studies at the University of Zurich. Vertebrate paleontologist Jorge Velez-Juarbe with the Natural History Museum of Los Angeles County said the study will not only serve as a key reference for debunking the myth that megalodon still exists, but its novel methods will influence the future of scientific research of extinct animals and plants. Jorge Velez-Juarbe “The methodology that the authors used had only been previously employed to determine extinction dates in historical times, such as to estimate the extinction date of the dodo bird,” Velez-Juarbe said. “In this work, scientists applied that same methodology to determine the extinction of an organism millions of years ago, instead of hundreds. It’s a new tool that paleo biologists didn’t have, or rather had not thought of using before.” 10 » UF study: Megalodon shark became extinct 2.6 million years ago » University of Florida UF study: Megalodon shark became extinct 2.6 million years ago Published: October 22 2014 Category:Research GAINESVILLE, Fla.

--- A new University of Florida study dismisses claims that megalodon is still alive by determining a date of extinction for the largest predatory shark to ever live. Researchers from UF and the University of Zurich hope the study appearing online today in the journal PLOS ONE showing the species became extinct 2.6 million years ago will clarify public confusion. The study may also one day help scientists better understand the potential widespread effects of losing the planet’s top predators, said lead author Catalina Pimiento. “I was drawn to the study of Carcharocles megalodon’s extinction because it is fundamental to know when species became extinct to then begin to understand the causes and consequences of such an event,” said Pimiento, a doctoral candidate at the Florida Museum of Natural History on the UF campus. “I also think people who are interested in this animal deserve to know what the scientific evidence shows, especially following Discovery Channel specials that implied megalodon may still be alive.” The study represents the first phase of Pimiento’s ongoing reconstruction of megalodon’s extinction. As modern top predators, especially large sharks, are significantly declining worldwide due to the current biodiversity crisis, Pimiento said this study serves as the basis to better understand the consequences of these changes.

“When you remove large sharks, then small sharks are very abundant and they consume more of the invertebrates that we humans eat,” Pimiento said. “Recent estimations show that large-bodied, shallow-water species of sharks are at greatest risk among marine animals, and the overall risk of shark extinction is substantially higher than for most other vertebrates.” Pimiento plans to further investigate possible correlations between changes in megalodon’s distribution and the evolutionary trends of marine mammals, such as whales and other sharks. “When we calculated the time of megalodon’s extinction, we noticed that the modern function and gigantic sizes of filter feeder whales became established around that time,” Pimiento said. “Future research will investigate if megalodon’s extinction played a part in the evolution of these new classes of whales.” The slowly unraveling details of megalodon’s extinction and various aspects of its natural history have consumed Pimiento’s research for the past six years, including ongoing analysis of megalodon’s body size and a 2010 PLOS ONE study that proposed Panama served as a nursery habitat for the species.

For the new study, researchers used databases and scientific literature of the most recent megalodon records and calculated the extinction using a novel mathematical model proven reliable in recent experimental testing by study co-author Christopher F. Clements with the Institute of Evolutionary Biology and Environmental Studies at the University of Zurich. Vertebrate paleontologist Jorge Velez-Juarbe with the Natural History Museum of Los Angeles County said the study will not only serve as a key reference for debunking the myth that megalodon still exists, but its novel methods will influence the future of scientific research of extinct animals and plants. “The methodology that the authors used had only been previously employed to determine extinction dates in historical times, such as to estimate the extinction date of the dodo bird,” Velez-Juarbe said. “In this work, scientists applied that same methodology to determine the extinction of an organism millions of years ago, instead of hundreds. It’s a new tool that paleo biologists didn't have, or rather had not thought of using before.” Credits Extinction of Megalodon Learning Resources The Extinction of Megalodon It is highly unlikely a single cause did in Megalodon.

During its 14-million-year tenure, Megalodon was distributed nearly world-wide: its fossil teeth are known from Europe, Africa, North and South America, southern Asia, Indonesia, Australia, New Caledonia, and New Zealand. In general, widely distributed species are better able to persist through periods of environmental change than species with small or patchy distributions. Under adverse conditions, a few localized populations may dwindle and eventually disappear, but a cosmopolitan species like Megalodon is likely to endure. This mighty predator was therefore probably snuffed by an unfavorable combination of many different factors, at least some of which had far-reaching effects. Major Environmental Changes The world Megalodon inherited was very different from the one it left. Between Megalodon's appearance in the mid-Miocene (16 million years ago) and its extinction in the Plio-Pleistocene (1.6 million years ago), a barrage of large-scale changes occurred that affected the marine environment. Like shards of glass floating on molasses, the continents continued their languorous wanderings across the face of the planet, changing both land and sea as they went.

Africa slammed into Europe during the Oligocene Epoch, reducing the interconnected Tethyan seaway to isolated bodies of water (today represented by the Mediterranean, Black, Caspian, and Aral seas). During the Miocene, the Indian subcontinent crashed into Asia, slowly crumpling the inland topography to help form the Himalayas. Similar tectonic altercations pushed up the Rockies and Andes mountains. These orogenic effects drastically altered global patterns of wind and rain as the continents jostled and shuffled into their present, familiar positions. The widespread cooling that had begun in the early Oligocene (about 35 million years ago) - combined with changes in wind and precipitation patterns - reduced the temperature at mid-latitudes by about 27 degrees Fahrenheit (15 degrees Celsius) and eventually resulted in a period of major glaciation at the poles by the late Miocene, about 10 million years ago. Between 7 and 3 million years ago, the Isthmus of Panama rose from the seafloor, joining North and South America and eliminating the last traces of the circum-tropical seaway that may have enabled Megalodon to disperse world-wide. These terrestrial changes provoked ripple effects in the sea.

Newly-formed mountains redistributed precipitation, creating rain shadows on their leeward sides. This redistribution of water caused many shallow inland seas to dry up, creating expansive salt flats that created insurmountable osmotic challenges for aquatic life. The Atlantic continued to spread on either side of the mid-oceanic rift - a gigantic tear in the seafloor into which magma from deep in the Earth is extruded, pushing apart the Old and New Worlds as inexorably as a couple in which the partners have stopped speaking to one another. Among other effects, this seafloor spreading caused the Gulf Stream to slow, thereby reducing upwelling of cold, nutrient-rich water near the southeastern parts of North America. Such upwellings were absolutely vital to supporting the rich web of marine life that ultimately provided a food source for Megalodon. It is probably no coincidence that the cetotheriids (early baleen whales) became extinct about the same time as Megalodon. Glaciation occupied much of the planetary water supply, locking it away in massive sheets of opalescent ice. Consequently, the sea level dropped some 650 feet (200 metres) and allowed many shallow coastal areas to dry up.

Thus, through lowered temperature and sea level, Megalodon lost large areas of suitable habitat. Shrinking Habitat To a greater or lesser extent, all living lamnids - including the White Shark - have a modified circulatory system that enables them to retain metabolic heat and extend their range into chilly waters. With the exception of the Shortfin Mako (Isurus oxyrinchus), which makes a good living even in tropical waters, all extant lamnids are primarily cold-water animals. Although some lamnids - like the White Shark - occasionally visit warmer waters, very few actually live there. Like the primates slathered in coconut oil on tropical beaches, warm water lamnids are generally tourists. And, like their human counterparts, they eventually go home. In contrast, megalodon does not seem to have extended its range into cool temperate waters. Despite its enormous body mass, megalodon may not have shared the lamnids' ability to retain significant metabolic heat. This shortcoming may have effectively trapped Megalodon in discrete, ever-decreasing puddles of warm coastal waters.

If, as Robert Purdy's paleoecological study suggests, Megalodon was limited to warm waters and relied on coastal areas as pupping grounds - no matter from whence it descended or what it looked like - it had a very sandtiger-like life history. And this may have led to Megalodon's ultimate undoing. Tropical waters are relatively nutrient-poor compared with those of temperate zones. In the western North Atlantic, loss of upwelling by the end of the Pliocene (about 1.6 million years ago) may have left Megalodon trapped in waters unable to supply sufficient food to fuel its titanic mass. Due to an inability or unwillingness to expand its range to richer, colder waters, Megalodon may well have starved to death. In addition, lowered sea-level at about the same time may have left Megalodon without nursery areas relatively free from predators large and well-armed enough to snack on its pups.

Because most coastal water available at the end of the Pliocene was near or over where the continental shelf drops off into oceanic depths, large pelagic predators such as Killer (Orcinus orca) and False Killer (Pseudorca crassidens) whales may have been able to snap up the 12-foot (4-metre) Megalodon pups. In modern sharks, access to predator-free nursery areas is known to be an important factor in determining survival of pups. Thus, due to environmental changes, Megalodon may have been 'hit' from both sides: the adults were too large to get enough to eat and the juveniles were too small not to be eaten by other predators. Bad for Megalodon, Good for Us? The rise of the Isthmus of Panama stimulated many ecological changes. In addition to sundering two oceans, this event linked the Americas, allowing animal migrations that forever changed New World ecology. Terrestrial species that had long been separated by impassable depths met, and in the face of new predators and diseases, many vanished. Paleontologist Steven Stanley has recently proposed that the rise of the Panamanian Isthmus may have also spurred the rise of human intelligence half the globe away.

According to Stanley's intriguing but controversial theory, when Panama severed the link between the Atlantic and Pacific, the flow of deep ocean currents was changed dramatically which, in turn, had profound effects on Earth's climate. Warm currents were diverted away from the Arctic causing this region - and eventually the whole northern hemisphere - to chill. Between 3.2 and 2.5 million years ago, the Earth plunged into an ice age, triggering the oscillating cycle of glacial advances and retreats that continues to this day. This ice age brought cooling and drying, even to faraway Africa. Eastern African forests shrank and our early ancestors, the ape-like australopithicines, were forced to abandon lives spent mostly in trees. The few who survived evolved into Homo, man-like creatures that walked upright. With their hands essentially free for the first time in evolutionary history, these early humans could care for infants who were helpless and slow to mature. And only with that extra time during childhood development could humans begin evolving large, complex brains. Thus, what may have been an unlucky break for Megalodon, may have been a lucky one for us. In the Shadow of Megalodon We will probably never know for sure why Megalodon became extinct.

Scattered distribution, insufficient food, or increased vulnerability of its pups may all have played a role. Or perhaps some other combination of factors conspired to snuff Megalodon. Yet the White Shark survives to this day. This species may have survived due to its ability to exploit the rich feeding available in cool temperate waters. Yet the White Shark is no more invincible than Megalodon proved to be. Like other sharks, the Great White matures late in life and has few pups per litter, severely limiting its ability to replace itself. This reproductive strategy has proven very sound in stable environments with few natural enemies. But evolution has simply not equipped the Great White to deal with the most complete and deadly predator the world has ever known. It may be the White Shark's ultimate misfortune to share a planet with us. Megalodon Shark Sightings? No, 60-Foot-Long Predators Went Extinct 2.6 Million Years Ago : Science : Latin One Megalodon Shark Sightings?

No, 60-Foot-Long Predators Went Extinct 2.6 Million Years Ago Oct 27, 2014 06:42 AM EDT Sign up to receive the lastest news from LATINONE LAS VEGAS - SEPTEMBER 30: One of the world's largest set of shark jaws comprised of about 180 fossil teeth from the prehistoric species, Carcharocles megalodon, which grew to the size of a school bus, is displayed at the Venetian Resort Hotel Casino September 30, 2009 in Las Vegas, Nevada. Auctioneers Bonhams & Butterfields hope the fossil will fetch about USD 900,000-1.2 million when it is auctioned off on October 3 at the Venetian as part of their Natural History auction.

The centerpiece of the lot of 50 fossils being auctioned is a 66-million-year-old Tyrannosaurus rex skeleton dubbed 'Samson.' The 40-foot-long female dinosaur fossil, excavated in South Dakota in 1992, contains about 170 bones and is said to be the third most complete T. rex skeleton ever unearthed. Bonhams & Butterfields is hoping Samson will fetch more than USD 6 million at the auction. (Photo : Getty) Whales are considered as the largest animal in the present, but before that, the ancient Megalodon sharks ruled the seas, and they are believed to have led whales to grow in size. According to a report from Tech Times , the Megalodon sharks are the largest sharks known to have ever lived, with each tooth measuring up to seven inches. These mega sharks are also thought to be the most fearsome killers in the ocean before their eventual extinction. Researchers at the University of Florida and University of Zurich revealed what made the 60-foot long Megalodon sharks to go extinct in the journal PLOS ONE.

The researches utilized Optical Linear Estimation (OLE) and discovered the exact date when the Megalodon sharks perished, Capital Wired reported. The researchers identified the records of the 42 most recent fossils by using the Paleontology Database, a large online compilation of fossil data. Advertisement The technique doesn't exactly pinpoint the exact date of the extinction of the great sea creature, but statistically, it dates back to the "middle Miocene Epoch (15.9 million to 11.6 million years ago) and the Pliocene Epoch (5.3 million to 2.6 million years ago)," according to The Economic Times . These epochs are the time when baleen whales started growing in size and the Megalodon sharks began dying out. Tech Times adds that the extinction of the Megalodon sharks, which preyed mainly on dolphins, whales, and other marine creatures, caused the ancient baleen whales to thrive in size. Because of the lack of competition, the ancient whales flourished. "Our results suggest that C. megalodon went extinct around 2.6 Ma.," according to the researchers as cited by Tech Times.

"Furthermore, when contrasting our results with known ecological and macro-evolutionary trends in marine mammals, it became evident that the modern composition and function of modern gigantic filter-feeding whales was established after the extinction of C. megalodon," the report adds. Catalina Pimiento, a study researcher from the department of biology at the University of Florida, says that the study paved way for the researchers to better understand the implications when a predator disappears entirely from the top of the food chain. "When you remove large sharks, then small sharks are very abundant and they consume more of the invertebrates that we humans eat. Recent estimations show that large-bodied, shallow-water species of sharks are at greatest risk among marine animals, and the overall risk of shark extinction is substantially higher than for most other vertebrates," Pimiento said in the Tech Times report. © 2015 Latin One. All rights reserved. Do not reproduce without permission. Sign up to receive the lastest news from LATINONE Advertisement When Did Megalodon Disappear From The Oceans? | IFLScience When Did Megalodon Disappear From The Oceans?

26114 Plants and Animals Karen Carr, via Wikimedia Commons Around 28 million years ago, the largest shark to have ever lived on Earth roamed the seas, tearing apart large marine mammals such as whales and dolphins. Measuring up to 18 meters in length, armed with teeth up to 7 inches long, the iconic Carcharocles megalodon (“ Megalodon ”) was a formidable predator. Although it has been widely regarded as extinct by the scientific community due to a lack of sightings and recent specimens, a mockumentary by the Discovery Channel perpetuated the idea that this apex predator could still be lurking deep in the ocean, avoiding detection by scientists. And of course, absence of evidence is not necessarily evidence of absence. But now, a comprehensive new study by researchers at the University of Florida and the University of Zurich has suggested that this ferocious vertebrate became extinct some 2.6 million years ago, rejecting popular ideas that Megalodon still survives today. The work has been published in PLOS ONE . Megalodon fossils, in particular teeth, have been unearthed in a considerable number of places across the globe, suggesting that this animal was a cosmopolitan fish that inhabited a wide range of marine environments.

These fossils generally range from the middle Miocene (15.9-11.6 million years ago [Ma]) to the Pliocene (5.3-2.6 Ma). Despite the abundance of fossils, surprisingly, little was known about the extinction of Megalodon. Researchers are particularly interested in the extinction of apex predators because of the downstream effects on the food chain that can be triggered, but working out when these events likely occurred can be tricky due to incomplete fossil records. To gain a better understanding of the extinction of this animal, researchers sifted through the Paleobiology Database to identify the most recent Megalodon fossils and found a total of 53. Of these records, 42 were considered reliable, so only these were included in the analysis. The age of these specimens lies within a range of an upper and lower date estimate, so to account for this uncertainty they ran 10,000 simulations for each fossil. This then selected the most likely age between these boundaries. They then applied a technique called optimal linear estimation to infer when Megalodon became extinct. This involves examining the distribution of gaps between fossil dates through time, study author Chris Clements told Live Science .

Although it can’t give a specific date for when the animal became extinct, it provides the most statistically likely extinction date, he said. According to the calculations, Megalodon became extinct around 2.6 Ma and is unlikely to have survived after this date. Six of the simulations actually inferred an extinction date after the present day, which would mean that it cannot be considered extinct. But because over 99.9% of the simulations gave a date in the past, the team rejected the hypothesis that Megalodon survives today. Hopefully, this will help dispel the popular myth that Megalodon is still skulking somewhere in our oceans. Interestingly, the inferred date of extinction fell around the same time that modern, gigantic filter-feeding whales became established, suggesting that the disappearance of Megalodon may have contributed to the evolution of these animals. Future studies will examine this further.

Question: The animal Megalodon went extinct 2.6 million years ago. What type of animal was it?
Answer: a Shark