An NC State researcher announced the discovery of a new species of dinosaur.The new species is part of the Tyrannosaurus rex family.The fossil was found in Utah.It was identified as Moros-Intrepidus and lived approximately 96 million years ago.But, unlike the T-rex, which stood about 12 feet tall and weighed up to eight tons, the Moros was between three and four feet tall.Researchers said they believe Moros fills in the timeline between the earliest, smaller Tyrannosaurus and the T-rex. </s> SALT LAKE CITY — Turns out, arid southern Utah was once a lush, prehistoric delta and the hunting grounds of a mule-deer-sized predecessor to the well-known 10-ton apex predator, Tyrannosaurus rex.

Details of the oldest Cretaceous Tyrannosaur species yet discovered in North America were published Thursday in the journal Communications Biologyby North Carolina State University paleontologist, and University of Utah graduate, Lindsay Zanno.

Moros intrepidus — "harbinger of doom" — according to Zanno's paper, is 96 million years old and helps fill in a sizeable gap in the fossil record from the 80-million-year-old giant made famous by movies like "Jurassic Park" to evidence of much earlier related species' dating back 150 million years. While scientists believe T. rex rose to become the alpha predator of the late Cretaceous period, for the 6-foot, 170-pound moros roaming Emery County back in the day, things were much different.

"With a lethal combination of bone-crunching bite forces, stereoscopic vision, rapid growth rates, and colossal size, tyrant dinosaurs reigned uncontested for 15 million years leading up to the end-Cretaceous extinction – but it wasn’t always that way,” Zanno said in a statement. “Early in their evolution, tyrannosaurs hunted in the shadows of archaic lineages such as allosaurs that were already established at the top of the food chain.”

The 70 million year gap in the fossil record for North American tyrannosaurs has left scientists scratching their heads about how the now-infamous tyrant dinosaur evolved to surpass and dominate other predators of the time. Zanno chose her Utah site specifically because of its fossil evidence from this missing era and has been working in the area for over a decade. She's also had a previous discovery from a nearby site of a giant meat-eating dinosaur called Siats meekerorum_._

Zanno said while her latest discovery was a diminutive creature for the times, it already had a combination of traits that would help propel it up the ladder of dominance.

“Moros was lightweight and exceptionally fast,” Zanno said. “These adaptations, together with advanced sensory capabilities, are the mark of a formidable predator. It could easily have run down prey, while avoiding confrontation with the top predators of the day."

“Although the earliest Cretaceous tyrannosaurs were small, their predatory specializations meant that they were primed to take advantage of new opportunities when warming temperatures, rising sea-level and shrinking ranges restructured ecosystems at the beginning of the late Cretaceous.

“We now know it took them less than 15 million years to rise to power.” </s> Before Tyrannosaurus rex became the towering king of dinosaurs, its other tyrannosaur cousins were much smaller, roughly the size of a deer. The evolution of these smaller versions into T. rex is well documented in Asia, but in the North American fossil record, there’s been a 70-million-year gap in evolutionary records—until now.

Now, fossil evidence of a new tyrannosaur species closes that gap by about 15 million years. The new species is dubbed Moros intrepidus and it roamed what is now modern-day Utah about 96 million years ago, according to a new study published in Communications Biology. This pint-size T. rex predecessor—whose name is Greek for impending doom—might just help scientists understand how tyrannosaurs eventually rose to the top of the food chain in North America.

Tyrannosaurs in the late Jurassic and early Cretaceous period would have answered to a different top predator: allosaurs. When allosaurs were top dog, tyrannosaurs would have been small-to-medium sized. During this time, however, these early tyrannosaurs were developing predatory adaptations—like big, sharp teeth—that would help them easily step in as an apex predator when allosaurs disappeared by roughly 80 million years ago, according to Michael Greshko for National Geographic.

Paleontologist Lindsay Zanno of the North Carolina Museum of Natural Science and North Carolina State University and her team had been scouring the rocky deserts of Utah for over a decade when they finally found a limb bone sticking out of the ground in 2012. Over the course of a few years, they carefully retrieved the bone and several others from the earth. The samples were extremely fragmented, she says, but they were able to reassemble what appeared to be a right hind leg.

By counting growth rings in the bone, they determined the specimen was at least seven years old, ruling out the possibility that Moros could have been a juvenile of a larger tyrannosaur, reports Ed Yong at The Atlantic. The unique shape of the foot and upper leg bone helped the team determine Moros was the oldest Cretaceous-era dinosaur discovered in North America.

“What I find most interesting about what Moros can teach us about tyrannosaur evolution is that we often think about tyrannosaurs as being such incredible predators, that they were destined to rule the late Cretaceous ecosystems,” Zanno tells Smithsonian.com. “But, in fact, they were living in the shadows of these archaic dinosaur lineages when they arrived here in the North American continent. And it wasn’t until those top predators went extinct, vacating those niches in the ecosystem, that tyrannosaurs were primed and ready to take over, and they did this very quickly.”

From 80 million years ago to 150 million years ago, the tyrannosaur fossil record in North America is sparse, reports Greshko for National Geographic. There are plenty small tyrannosaur skeletons from around 150 million years ago, and then gigantic remains from 80 million years ago—but a blank slate in between, reports The Atlantic’s Yong. The discovery of 96 million-year-old Moros provides evidence that tyrannosaurs were still on the continent during the mid-Cretaceous period and that tyrannosaurs were able to evolve from the size of a horse to the size of a school bus about 16 million years.

Zanno says Moros’ long feet would have given it incredible speed, and it would have had stereoscopic vision and a highly attuned sensory system that would help its later forms dominate ecosystems. Moros differs from T. rex, though, in its size as well as its teeth.

“[Between Moros and T. rex] there were lots of intermediate [evolutionary] stages,” Hans Sues, curator of vertebrate paleontology at the National Museum of Natural History, tells Smithsonian.com. “We can see that they get bigger, that their teeth get more robust. These early tyrannosaurs have blade-like teeth, but by the time you get to T. rex, it was a predator that could crush bones so it has really massive, strong teeth that kind of look like a big banana with cutting edges.”

Sues says while he’s “surprised and excited” about the new finding, he hopes to find more complete remains of these early tyrannosaurs to better understand what they looked like and determine the timeline of specific evolutionary changes.

Zanno hopes they can eventually pinpoint exactly when allosaurs died out to help determine how tyrannosaurs made such a massive jump in size a relatively short period.

“When and where and why and how [tyrannosaurs] ascended to these top predator roles in North America has remained a mystery,” Zanno says. “We just haven’t had the fossils to answer that question. There’s still an enormous gap and discoveries that need to be made.” </s> Feb. 22 (UPI) -- Scientists have discovered a new tyrannosaur species, a miniature T. rex that roamed North America some 96 million years ago.

The new species, Moros intrepidus, is the oldest Cretaceous tyrannosaur yet found in North America.

The early fossil record has provided evidence of a diversity of medium-sized, primitive tyrannosaurs dating to the Jurassic period, around 150 million years ago. And 80-million-year-old Cretaceous deposits have offered plenty of fossil evidence of large tyrannosaurs.

Until now, paleontologists have learned little of the 70-million-year gap separating the two fossil-rich deposits. The newly discovered species could help scientists better understand how T. rex and its ferocious peers became apex predators.

"When and how quickly tyrannosaurs went from wallflower to prom king has been vexing paleontologists for a long time," Lindsay Zanno, paleontologist at North Carolina State University, said in a news release. "The only way to attack this problem was to get out there and find more data on these rare animals."

Zanno and her colleagues found the new fossil evidence, including teeth and a hind limb, hiding in the rocks of Utah's Upper Cedar Mountain Formation -- deposits dating to the beginning of the Late Cretaceous.

Researchers described the Moros intrepidus fossil in the journal Communications Biology.

Unlike the tyrannosaurs that came later, like T. rex, the newly discovered species was relatively small. The mini tyrannosaur was roughly the size of a modern mule deer, measuring just three to four feet tall from the hip.

Despite, Moros intrepidus's diminutive size, scientists claim the species was still a fearsome predator.

"Moros was lightweight and exceptionally fast," Zanno said. "These adaptations, together with advanced sensory capabilities, are the mark of a formidable predator. It could easily have run down prey, while avoiding confrontation with the top predators of the day."

According to Zanno, the new species offers proof that tyrannosaurs had all the tools to become apex predators. All that was lacking was size.

"Although the earliest Cretaceous tyrannosaurs were small, their predatory specializations meant that they were primed to take advantage of new opportunities when warming temperatures, rising sea-level and shrinking ranges restructured ecosystems at the beginning of the Late Cretaceous," Zanno said. "We now know it took them less than 15 million years to rise to power."

When scientists situated Moros intrepidus on the tyrannosaur family tree, they determined the species' relatives hail from Asia. Research last year showed the land bridge connecting Siberia and Alaska served as a migrational superhighway for dinosaurs -- just as it did millions of years later for early humans.

"T. rex and its famous contemporaries such as Triceratops may be among our most beloved cultural icons, but we owe their existence to their intrepid ancestors who migrated here from Asia at least 30 million years prior," Zanno said. "Moros signals the establishment of the iconic Late Cretaceous ecosystems of North America." </s> When you think of a Tyrannosaurus Rex, you presume it was always the king of the dinosaurs.

But a newly-discovered fossil tells us that wasn't the case.

The fossil, found in Utah, is believed to be of the creature, Moros Intrepidus.

But unlike the T-Rex, which stood about 12 feet tall and weighed up to eight tons.

The Moros was between three and four feet tall.

Researchers believe Moros fills in the timeline between the earliest, smaller Tyrannosaurs and the T-Rex.

And while lightweight, the Moros was quite fast and, over millions of years, evolved into the more memorable T-Rex.

The findings were published Thursday in Communications Biology. </s> The Tyrannosaurus rex may have been one of the mightiest beasts to roam the ancient Earth — though whether he was more of a scavenger than a predator has been the topic of much debate — but Rex might have never existed at all if not for his much smaller predecessors.

A newly discovered species of Tyrannosaur found in Utah is helping scientists to better understand how Tyrannosaurs arrived on the continent and spread across North America. It’s an ancestor of the Rex, but unlike its much larger successor this new species, called Moros intrepidus, wasn’t the top of its food chain.

Researchers from North Carolina State University published a new paper in Communications Biology describing the discovery and the world the new species would have lived in. Intrepidus lived in a time where larger bipedal predators like allosaurs ruled the land.

The species was traced to the late Cretaceous period, long before the age of the Rex, and a time when it would have had to contend with much larger predators and prey. Intrepidus would only have been about the size of a modern day deer, between three and four feet tall at its hip, but it was still capable of holding its own.

“Moros was lightweight and exceptionally fast,” Lindsay Zanno, lead author of the work, said in a statement. “These adaptations, together with advanced sensory capabilities, are the mark of a formidable predator. It could easily have run down prey, while avoiding confrontation with the top predators of the day.”

Gradually, over tens of millions of years, Tyrannosaurs took the top spot, with larger and larger species that grew to dominate the ancient Earth. Exactly when and how that change took place is something that paleontologists around the world are still figuring out, but new discoveries like this one bring us a little bit closer. </s> Tyrannosaurus rex wasn’t always king of the prehistoric jungle.

One hundred million years ago, carnivorous allosaurs were considered an apex predator. But how and when the theropods were replaced by tyrannosaurs remains a mystery.

A newly discovered, “diminutive” relative of the fearsome fossil helps fill a 70-million-year gap, linking early tyrannosaurs to the world-famous T. rex.

A team from the North Carolina Museum of Natural Sciences and North Carolina State University recently unearthed Moros intrepidus, a small tyrannosaur that lived about 96 million years ago in modern-day Utah.

A paper describing the oldest Cretaceous tyrannosaur species discovered in North America was published this week in the journal Communications Biology.

Medium-sized, primitive tyrannosaurs have been found in North America dating as far bas as the Jurassic (about 150 million years ago). By the Cretaceous—some 81 million years ago—the dinosaurs had grown into the enormous, iconic predators we know today.

Their growth spurt, however, was never documented; the fossil record between the two periods has long been a blank state.

“When and how quickly tyrannosaurs went from wallflower to prom king has been vexing paleontologists for a long time,” according to study co-author Lindsay Zanno, a researcher at NC State and the North Carolina Museum of Sciences. “The only way to attack this problem was to get out there and find more data on these rare animals.”

Which is exactly what she did.

A decade spent hunting for remains finally yielded teeth and a hind limb from the new old lizard. Even more telling: The lower leg bones of Moros were discovered in the same area Zanno previously found Siats meekerorum, a giant meat-eating carcharodontosaur that lived during the same period.

Tiny by comparison, Moros stands only three or four feet tall at the hip—about the size of a modern mule deer.

Zanno estimates that their Moros was more than seven years old when it died, nearly full grown.

“Although the earliest Cretaceous tyrannosaurs were small, their predatory specializations meant that they were primed to take advantage of new opportunities when warming temperatures, rising sea-level, and shrinking ranges restructured ecosystems at the beginning of the Late Cretaceous,” Zanno explained. “We now know it took them less than 15 million years to rise to power.”

The team also uncovered the origin of T. rex‘s lineage in North America, suggesting that its closest relatives were from Asia.
• None New Dinosaur Species With Spiny Backbone Discovered in Patagonia </s> Tyrannosaurus rex might have been the “tyrant lizard king,” but before the mighty T. rex stomped across what is now North America, it ancestors weren't exactly living like royalty: They were tiny, gangly, and quick on their feet, adapted to life in the shadows of far larger carnivores.

Now, a fossil found in Utah is helping paleontologists better understand how this region's tyrannosaurs went from ecological paupers to princes. Weighing about 170 pounds and standing less than five feet tall, the newly named species Moros intrepidus is one of the smallest dinosaurs of its kind dating back to the Cretaceous period, the time between 66 million and 145 million years ago.

At 96 million years old, Moros is also the oldest Cretaceous tyrannosaur skeleton found in this region, pushing back that particular record by 15 million years. (Get the best look yet at the face of a tyrannosaur.)

“What Moros does for us is help us understand the who, what, why, where, and when of how tyrannosaurs ascended to top predator roles on the North American continent,” says paleontologist Lindsay Zanno of the North Carolina Museum of Natural Sciences, whose team reports the fossil find today in the journal Communications Biology.

Small wonder, then, that this dinosaur has the genus name Moros: the Greek embodiment of impending doom.

Out on a limb

At the dawn of the Cretaceous, tyrannosaurs were nowhere near the titans we imagine today. Instead, they were small, scrappy predators that hunted alongside much larger meat-eating dinosaurs called allosaurs. By 80 million years ago, North America's allosaurs had faded, and tyrannosaurs had grown about 10 times larger—filling in the allosaurs' apex niche in spectacular fashion.

Dinosaurs 101 Over a thousand dinosaur species once roamed the Earth. Learn which ones were the largest and the smallest, what dinosaurs ate and how they behaved, as well as surprising facts about their extinction.

It remains a mystery, though, how North America's tyrannosaurs got big, since there's a major gap in the continent's mid-Cretaceous fossil record. With the exception of some isolated teeth, paleontologists had been missing skeletal evidence of North American tyrannosaurs from about 150 million years ago to 80 million years ago.

As a result, researchers including Zanno kept searching mid-Cretaceous rock formations. In 2013, Zanno struck gold: While walking through her field site in central Utah's Cedar Mountain Formation, she unexpectedly saw limb bones jutting out of a hillside.

“We've been hunting in this area for 10 years, and these are the only bones of this animal we've ever recovered,” she says. “It takes teams a very, very long time and and an awful lot of luck.”



Dinosaur explorer

The foot bones of Moros are so skinny, it looks ganglier than even the juveniles of later, larger tyrannosaur species. But Moros was no toddler: Close study of the bones' cross sections show that the dinosaur was at least six or seven years old when it died, making it close to adulthood.

The tiny fossil suggests that North America's tyrannosaurs stayed small until at least the time of Moros, which means that tyrannosaurs grew to movie-monster size in just 16 million years—an evolutionary sprint. Perhaps fittingly, the Moros hind limb has some of the running-adapted features seen in later, bigger tyrannosaurs. (Could you have outrun a T. rex? Here's the science.)

“Moros is important in that way; it's the first hint of tyrannosaurs that eventually became the big ones,” says Thomas Carr, a paleontologist at Carthage College and a tyrannosaur expert who wasn't involved with the study.

What's more, Moros most closely resembles tyrannosaurs that lived in Asia in the early Cretaceous. The find suggests that the ancestors of Moros crossed a land bridge from Asia into North America, as part of an exchange between the two continents that's well-documented in other dinosaur groups. To honor its journey, researchers gave Moros the globe-trotting species name of intrepidus.

Now that her team has unveiled Moros, Zanno is eager to describe its swampy home. The same rocks that once held Moros also have yielded the massive allosaur Siats and several plant-eating dinosaurs, including some that are thought to have burrowed. She is also working with researchers to study the area's fossil plant life. </s> A team of researchers, including UNM Honors College Professor Jason R. Moore, has found a new species of tyrannosaur dinosaur — the most popular of the prehistoric creatures.

After the fossils were pulled out of the muddy banks of a Montana river, the team was able to analyze the texture of the facial bones of the new species. The findings suggest that the face of tyrannosaurs was covered in a scaly protective layer with a high degree of tactile sensitivity, similar to crocodiles.

“Being a tyrannosaur, they had really small arms,” says Moore. “They wouldn’t be able to interact with their environment with their hands the way mammals do — find food, build nests, tend to eggs and young. In order to do these things, Daspletosaurus needed to use its feet or head. The discovery and analysis of the tyrannosaur shows that the dinosaur had a developed face sensitivity similar to the sensitivity in our finger tips, suggesting it could use its snout for all those complex ecological interactions, similar to the way crocodiles do today.”

An investigation by a team of scientists from Wisconsin, Australia, Louisiana, Montana and New Mexico has identified and named the new species of the tyrannosaur clan: Daspletosaurus horneri – “Horner’s Frightful Lizard.”

The species is named for the renowned dinosaur paleontologist, John “Jack” R. Horner, formerly curator at the Museum of the Rockies (MOR) in Bozeman, Montana. The tyrannosaur’s name honors his discoveries of numerous dinosaur fossils and his mentorship of so many students that launched them on to accomplished scientific careers. The name-bearing specimens are stored in the research collections of the MOR.

The fossil resources of Montana, where the new tyrannosaur was found, are central to studies of dinosaur evolution.

“Montana, similar to many Rocky Mountain states, has lots of rock exposed at the right time and right environment to contain dinosaurs,” says Moore. “The fossils are found preserved in ancient river channels and flood plains. If you know what you’re looking for, they are widespread.”

The research is led by Thomas Carr of Carthage College’s Department of Biology in Wisconsin, an expert on the evolution and growth of Tyrannosaurus rex and its closest relatives, collectively called tyrannosaurs.

The family tree

 In addition to adding a new species to the tyrannosaur family tree, the team’s research provides new information about the mode of evolution and life appearance of tyrannosaurs, specifically the face.

This latest study, published in Nature Publishing Group’s Scientific Reports, found evidence for a rare, nonbranching type of evolution in tyrannosaurs and that tyrannosaurs had scaly, lipless faces and a highly touch-sensitive snout.

“Daspletosaurus horneri was the youngest, and last, of its lineage that lived after its closest relative, D. torosus, which is found in Alberta, Canada,” says Carr. “The geographic proximity of these species and their sequential occurrence suggests that they represent a single lineage where D. torosus has evolved into D. horneri.”

Moore elaborated, “One of the difficulties in demonstrating this style of evolution is establishing that the different species don’t overlap in time. The new radiometric dates we measured help support this temporal separation between D. torosus and D. horneri.”

The research confirms that the ages of the two species shows that the evolution of the dinosaur was slow—happening over a span of 2.3 million years.

The team’s work literally changes the face of tyrannosaurs, which they found was covered by a lipless ‘mask’ of large flat scales and extensive patches of armor-like skin. This conclusion results from comparison of tyrannosaur skulls with those of crocodylians, birds and mammals, and earlier work by other researchers who had matched bone texture with different types of skin covering.

Jayc Sedlmayr, professor at the Louisiana State University Health Sciences Center New Orleans, explained, “Much of our research … was generated from lab based comparative anatomy, where you get arms deep in ‘blood and guts’ dissecting birds—living dinosaurs and crocodilians—their closest living relatives.”

The crocodile connection 

 “It turns out that tyrannosaurs are identical to crocodylians in that the bones of their snouts and jaws are rough, except for a narrow band of smooth bone along the tooth row,” explained Carr. “We did not find any evidence for lips in tyrannosaurs: the rough texture covered by scales extends nearly to the tooth row, providing no space for lips.”

“However, we did find evidence for other types of skin on the face, including areas of extremely coarse bone that supported armor-like skin on the snout and on the sides of the lower jaws. The armor-like skin would have protected tyrannosaurs from abrasions, perhaps sustained when hunting and feeding.”

The researchers found that, like in crocodylians, the snout and jaws of the tyrannosaurs are penetrated by numerous small nerve openings, allowing hundreds of branches of nerves to innervate the skin, producing a sensitivity similar to that of human fingertips.

This sensitivity is part of a bigger evolutionary story, explained Sedlmayr. “The trigeminal nerve has an extraordinary evolutionary history of developing into wildly different ‘sixth senses’ in different vertebrates, such as sensing magnetic fields for bird migration, electroreception for predation in the platypus bill or the whisker pits of dolphins, sensing infrared in pit vipers to identify prey, guiding movements in mammals through the use of whiskers, sensing vibrations through the water by alligators and turning the elephant trunk into a sensitive ‘hand’ similar to what has been done to the entire face of tyrannosaurs.”
A fossil from a new species of tyrannosaur named Moros intrepidus is discovered in the U.S. state of Utah. Scientists are using the find to better understand how Tyrannosaurus rex evolved during the Cretaceous period.