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Paleontologist Believes Cretaceous Mosasaur Might Have Specialized in Fish

Saturday, April 7, 2018

UC graduate student Samuel Garvey stands in front of a cast of a mosasaur skull that UC's Department of Biological Sciences acquired this year.

Takuya Konishi held up a fossil of a mosasaur, a ferocious marine reptile that lived alongside dinosaurs more than 65 million years ago.

The wishbone-shaped lower jawbone didn't look like much, but to Konishi it was a fantastic clue.

"Here is what I think is a new kind of ," said Konishi, an assistant professor of biological sciences at the University of Cincinnati. "I can say that from 'only' this much bone. But only is in quotation marks. This is a very good specimen."

With 18 peer-reviewed journal articles on the subject, Konishi is an internationally renowned expert on mosasaurs, the aquatic predator and unlikely hero of the 2015 blockbuster movie "Jurassic World."

The paleontologist in UC's McMicken College of Arts and Sciences has spent much of his career piecing together the lives of these predators that lived alongside Tyrannosaurus rex.

While visitors to museums see complete fossil skeletons of mosasaurs suspended in dramatic hunting postures, paleontologists more typically find a dull-colored fragment like the one Konishi held. Piece together enough of these fragments and the fossils begin to tell a story, he said.

"We're not dealing with 'Jurassic World,'" Konishi said. "It's a lot of detective work. That is the great appeal of paleontology. We're so limited with the evidence so it's our points of view we should sharpen and hone so we can shed new light on the discoveries."

A fossilized mosasaur found in Kansas in 1991 is suspended from the ceiling of UC's Geology-Physics Building where it is on public display. Credit: University of Cincinnati

Mosasaurs are more closely related to snakes and lizards than dinosaurs. While mosasaurs went extinct 65 million years ago, other  from that time, such as sea turtles, persisted. By learning more about mosasaurs, we can understand evolutionary processes such as extinction that influence species today, Konishi said.

"Superficially, mosasaurs look like the T. rex of the sea," he said. "They were apex predators, like killer whales today. They were bigger than the sharks of their time. They occupied every niche available to them."

Mosasaurs have a lot in common with today's monitor lizards, except they were true marine reptiles that never left the water and gave birth to live young. They were found off the coasts of every continent and dominated their marine habitats for about 30 million years. Scientists have identified about 70 species ranging in size from a bottlenose dolphin to a Greyhound bus.

And most of what is known about mosasaurs was pieced together from small bits of fossil collected and examined by paleontologists over the past 200 years.

"Every now and then you strike a gold mine and find something like this," Konishi said, holding up the intact jawbone. "You always have to be working on these less-optimal specimens so you can maximize the scientific value of the more complete specimens when they are discovered."

One recently discovered fossil, in particular, has captured the attention of Konishi and UC graduate student Samuel Garvey. It is one of the larger of known kinds of mosasaur called a tylosaur and was unearthed around Grande Prairie, Alberta, Canada, in what used to be a vast inland sea.

"In the time of Tyrannosaurus and his geologically older cousin Albertosaurus, the Western Interior Seaway stretched from what is now the Arctic Ocean all the way down to the Gulf of Mexico through the heart of North America," Konishi said.

About 70 species of mosasaur have been identified so far. Some were as small as dolphins while others were bigger than Greyhound buses. Credit: University of Cincinnati

Garvey is working on a quantitative model for interpreting both the preferred prey and the function of predator teeth based on their shape and variety. Mosasaurs are good models for this analysis since different species have unique dentition.

"They were . They were the big bads of the Cretaceous sea," Garvey said. "There are unique things about my specimen. So are there other high-latitude specimens that might show similar characteristics? Or is it anomalous?"

What is most striking about Garvey's 20-foot-long tylosaur, Konishi said, is its sharp but slender teeth.

Scientists think mosasaurs were opportunistic predators, hunting and eating most anything they could catch based on the fossilized stomach contents found in some specimens. Most had ferocious jaws and teeth that would have made them effective hunters of everything from  and hard-shelled squid to smaller mosasaurs, Konishi said.

"It's not that surprising, knowing how robust their teeth are," Konishi said. "They could eat almost anything. They didn't have to be choosy."

These conical teeth were durable, capable of crushing shell or digging into bone. The teeth of many specimens were worn, suggesting they got plenty of use biting into hard prey. And like sharks, they grew new teeth to replace older ones throughout their lives.

But the sharp, slender teeth in the mosasaur Garvey is studying probably wouldn't have been able to tackle such hard prey, Konishi said.

UC researchers study mosasaur teeth, among other clues, to learn more about their likely prey. Credit: University of Cincinnati

"That suggests that it was eating something different—most likely fish," he said.

If these mosasaurs primarily survived on fish, it's possible they could have lived alongside the generalist mosasaurs without the pressure of competition.

"How would you have two big predators in the same ecosystem without losing one from competition or natural selection? They probably relied on different prey," Konishi said.

Like snakes, mosasaurs also had a second row of dentition on the roof of their mouths called pterygoid teeth. Konishi said these would have helped mosasaurs grip and swallow slippery prey such as fish without also swallowing seawater.

Marine reptiles have novel ways of processing salt from the food and water they consume. While mammals can process and eliminate salt through their urine, reptiles typically have glands that help them expel it. Sea turtles have glands behind their tear ducts so they 'cry' to expel salt. Sea snakes have glands in their mouth, he said.
"Every time they flick their tongue, they remove salt. And marine iguanas sneeze out the salt," Konishi said.

Konishi said mosasaurs likely had salt glands as well to survive in their marine environment. These adaptations enabled lizards to colonize virtually every warm habitat on Earth.

"There are still many things from basic taxonomy to physiology to paleobiological questions we have about mosasaurs," Konishi said.

UC paleontologist Takuya Konishi poses with an ammonite fossil he discovered in Alberta, Canada, in 2011. Credit: Darren Tanke/Royal Tyrrell Museum of Paleontology

Paleontologists have found a treasure trove of mosasaur fossils in parts of Kansas and Alberta, Canada, that were underwater more than 80 million years ago.

One of these hotbeds is Hays, Kansas, home to Fort Hays State University's Sternberg Museum of Natural History. It was named for the Sternberg family, including George F. Sternberg, one of the first settlers to discover mosasaur fossils in Kansas after the Civil War, and his son Charles Sternberg, one of the museum's first curators.

Konishi spends a fair amount of his time fossil hunting as well in Alberta and the Canadian arctic.

"You just walk and use your eyes. Sometimes, you're literally on your knees. The closer you are to the ground, the better. Nobody ever looks for fossils on horseback," he said.

"Fieldwork is a fun part of the job. It's also very rewarding. It's hard work. It can be hot and sweaty," he said.

The prairie provinces of Canada are his favorite places for fieldwork.

"If you go out in the field there, you will find something. You always find something," he said. "And with that comes new discoveries."

The mosasaur is a perennial favorite of dinosaur lovers because of their immense size and menacing appearance. Konishi understands why mosasaurs are a pop-culture staple.

While the 2015 film "Jurassic World" spotlighted Konishi's research subject for a global audience, the moviemakers weren't sticklers for scientific accuracy, he said.

For starters, mosasaurs had mouths more like Komodo dragons than crocodiles. And the mosasaur featured in the movie's aquarium was far bigger than any known specimen.

Likewise, the monster portrayed on screen had knobby plates like a crocodile, which would have been a hindrance for truly aquatic reptiles. And—spoiler alert—a mosasaur probably couldn't have beached itself to grab a genetically engineered dinosaur by the tail.

"Being an expert makes me savvy about that pop-culture aspect of a charismatic prehistoric, toothy predator. And they are," he said. "So I enjoyed the movie."

Provided by: University of Cincinnati  

Source: https://phys.org

 

 

77 Interesting Facts About Dinosaurs

Friday, April 13, 2018

Interesting Facts about Dinosaurs

·  Dinosaurs were reptiles that lived on Earth from about 230 million years ago to about 65 million years ago.

·  Dinosaurs lived during a period of Earth’s history called the Mesozoic (“middle life”) Era. They lived during all three periods of this era: the Triassic, Jurassic, and Cretaceous.

·  Meat-eating dinosaurs are known as theropods, which means “beast-footed,” because they had sharp, hooked claws on their toes. In contrast, plant-eating dinosaurs tended to have blunt hooves or toenails.

·  Dinosaur skulls had large holes or “windows” that made their skulls lighter. Some of the largest skulls were as long as a car.

·  Scientists estimate that there were over 1,000 different species of non-avian dinosaurs and over 500 distinct genera. They speculate there are many still undiscovered dinosaurs and that there may be as many as 1,850 genera.

·  Dinosaurs lived on all the continents, including Antarctica.

·  Colorado’s nickname is the Stegosaurus State. The first ever Stegosaurus skeleton was found near Morrison, Colorado.

·  Some of the biggest plant eaters had to eat as much as a ton of food a day. This is similar to eating a bus-sized pile of vegetation every day.

·  Though mosasaurs, ichthyosaurs, pterosaurs, plesiosaurs are not technically dinosaurs. The term “dinosaur” refers to just land-dwelling reptiles that have a specific hip structure, among other traits.

·  While many people think dinosaurs were massive, dinosaurs were usually human sized or smaller. Scientists believe that the larger bones were just easier to be fossilized.

·  Some dinosaurs’ tails were over 45 feet long. Most dinosaurs had long tails that helped them to keep their balance when running.

·  The earliest named dinosaur found so far is the Eoraptor (“dawn stealer”). It was so named because it lived at the dawn of the Dinosaur Age. It was a meat eater about the size of a German shepherd. The first Eoraptor skeleton was discovered in Argentina in 1991.

·  Dinosaurs are divided into two groups by the structure of their hipbones. In the hips of saurischian, or lizard hipped, dinosaurs, one of the bones pointed forward. In the hips of ornithischian, or bird-hipped, dinosaurs, all the bones pointed backward. Ironically, scientists believe that birds evolved from lizard-hipped dinosaurs, not bird-hipped dinosaurs.

·  The word “dinosaur” was coined by British paleontologist Richard Owen in 1842. It is Greek, meaning “terrible lizard.” Rather than implying that dinosaurs were fearsome, Owen used the term to refer to their majesty and size.

·  The first dinosaurs that appeared during the Triassic Period 230 million years ago were small and lightweight. Bigger dinosaurs such as Brachiosaurus and Triceratops appeared during the Jurassic and Cretaceous periods.

·  The dinosaur with the longest name is Micropachycephalosaurus (“small thick-headed lizard”). Its fossils are usually found in China.

·  Dinosaurs dominated Earth for over 165 million years. Humans have been around for only 2 million years.

·  Many scientists believe that a massive meteorite hit the Yucatan Peninsula of Mexico 65.5 million years ago and caused the extinction of the dinosaurs as well as the pterosaurs and plesiosaurs. The 112-mile-wide crater was caused by a rock 6 miles in diameter. It would have hit Earth’s crust with immense force, sending shockwaves around the world. No land animal heavier than a large dog survived. However, animals such as sharks, jellyfish, fish, scorpions, birds, insects, snakes, turtles, lizards, and crocodiles survived.

·  No one knows exactly how long a dinosaur’s lifespan was. Some scientists speculate some dinosaurs lived for as long as 200 years.

·  The mass extinction of the dinosaurs and other animals that took place 65.5 million years ago is known as the Cretaceous-Tertiary extinction event, or the K-T event. Scientists have several theories for this extensive die-off. One theory proposes that small mammals ate dinosaur eggs until the population became unsustainable. Other scientists believe the cause was dinosaurs’ bodies becoming too big for their small brains, a great plaque decimating the population, starvation, or climate change.

·  Mary Anning (1799-1847) was one of the most famous of all fossil hunters. However, she was never taken as seriously as she should have been because she was a woman from a poor background whereas most scientists were men from wealthy families.

·  Scientists believe that some dinosaurs were cold blooded, others warm blooded, and still others not fully one or the other. Small meat eaters may have been warm blooded. Plant eaters who were not as active were probably cold blooded. A warm-blooded animal needs about 10 times more food than a cold-blooded animal the same size.

·  Explorer Roy Chapman Andrews found the first dinosaur nest known to science in 1923 in the Gobi Desert of Mongolia. Before he found the nest, scientists were unsure how dinosaur babies were born.

·  The largest dinosaur eggs were as large as basketballs. The bigger the egg, the thicker the shell. So if the eggs had been larger, dinosaur babies probably would not have been able to get out.

·  The first dinosaurs were carnivores, or meat eaters. Later herbivores (plant eaters) and omnivores (both meat and plant eaters) appeared.

·  Triceratops had the biggest skull with a solid shield than any other dinosaur. It was up to 6½ feet (2 m) long, with a bony shield over its neck.

***The newest challenger to the title of the “horned dinosaur with the biggest head” might be the impressive Titanoceratops (T. ouranos).  

·  Most dinosaurs were vegetarians.

·  The Stegosaurus has the smallest brain for its body size of any known dinosaur. Its body was the size of a van, but its brain was the size of a walnut.

·  One tribe of Native Americans—the Peigan people of Alberta, Canada—thought dinosaur skeletons belonged to “the fathers of buffaloes.” Englishmen 300 hundred years ago believed dinosaur bones came from an elephant or even giant humans.

·  The first recorded description of a possible dinosaur bone discovery dates back to 3,500 years ago in China. At the time, people did not know about dinosaurs, so they thought their discovery, which was some dinosaur teeth, belonged to dragons.

·  Measuring 50 feet, Liopleurodon was the biggest aquatic reptile, half the size of the blue whale.

·  Most meat-eating dinosaurs had bones filled with air. Though their bones were huge, they weren’t as heavy as they looked. Birds have the same kind of hollow bones.

·  Baby Mussaurus (“mouse lizard”) are the smallest dinosaur skeletons ever found. They would fit inside a shopping bag.

·  Small meat eaters were most likely the smartest type of dinosaurs.

·  Humans’ eyes face forward so that they can see in 3D. Plant-eating dinosaurs, like the Triceratops, had eyes looking out to each side, so they could watch for danger while they fed.

·  A newborn human baby has a bigger brain than most adult dinosaurs had. Whales and dolphins have the biggest brains of all living animals.

·  Most meat eaters walked on two feet. This made them faster and left their hands free to grab their prey. Most plant eaters walked on four feet to better carry their heavy bodies. Some plant eaters could balance on two feet for a short time.

·  Snakes and lizards shed their skin when they grow. Researchers believe that dinosaurs may have done the same.

·  Some dinosaurs may have had colorful skin, but scientists don’t know for sure. It’s likely that most dinosaurs had green and brown scales to help them hide among trees and plants.

·  While dinosaurs had the same set of leg bones, some had feet like a rhinoceros, elephant, bird, or a pig. The biggest footprints ever found were 3 feet (1 m) across and 4 feet long. Millipedes have more legs than any other animal—up to 750.

·  Dinosaurs often swallowed large rocks. These rocks stayed in the stomach and helped them grind up food.

·  Tyrannosaurus rex ate up to 22 tons of meat a year. It had jagged teeth 6 inches (15 cm) long. It couldn’t chew, so it swallowed its food in large chunks.

·  Deinosuchus was a huge prehistoric crocodile. It most likely had the strongest bite out of any dinosaur, including Tyrannosaurus rex. It weighed eight times as much as today’s crocodile.

·  Corythosaurus had a big, hollow crest connected to its nose. The crest worked like an echo chamber, letting it make a loud blast of noise.

·  Sauropods were the tallest animals that ever lived. Some were more than twice the height of a giraffe.

·  Struthiomimus (“ostrich mimic”), as well as other small hunters, made high-pitched, screechy noises similar to an ostrich.

·  Parasaurolophus had a crest that looked like half of a trombone. The male’s crest was up to 6 feet (1.8 m) long, which was the biggest out of all the dinosaurs.

·  Some scientists believe that Tyrannosaurus rex may have been able to run as fast as 18 mph (28 km/h). Other scientists believe it could not run at all because it was so big.

·  Slim dinosaurs such as Compsognathus and Ornithomimus were among the fastest dinosaurs. However, the cheetah can run faster than any dinosaur that existed.

·  Dinosaurs that could run on two legs were called bipeds.

·  Dinosaurs had different self-defense mechanisms. Some, like meat eaters, had sharp teeth. Plant eaters had long horns or sharp spikes. Other dinosaurs were covered in bony plates.

·  It is estimated that trillions of dinosaur eggs were laid during the Mesozoic era, though fossilized eggs containing embryos are rare.

·  All dinosaurs laid eggs. About 40 kinds of dinosaur eggs have been discovered.

·  Modern birds and reptiles have a single body opening for urination, defecation, and reproduction: a cloaca (Latin for “sewer”). Paleontologists believe that dinosaurs were similarly designed and reproduced by pressing their cloacas together in a “cloacal kiss.” Additionally, some dinosaurs may have had a penis like some birds do or other “intromittent organs” like crocodiles. Paleontologists believe a Tyrannosaurus rex male reproductive organ might have been up to 12 feet in length.

·  Like birds and reptiles today, dinosaurs built nests and laid eggs. Some even fed and protected their babies.

·  Plant-eating dinosaurs often lived together for protection, like herding animals today do. The herds ranged from just a few adults and their young to thousands of animals.

·  Sauropods (“Lizard-Footed”) could travel many miles a day on their huge legs. Their fossilized “trackways” or “superhighways” can still be seen today.

·  The Megalodon was the biggest prehistoric fish. It looked like a shark, though it was three times bigger.

·  Dinosaurs that lived near water often left the best fossils.

·  The biggest hunter was the Spinosaurus (“spine lizard”). It was up to 49 feet (15 m) long.

·  The biggest plant eater was the Patagotitan. It was up to 121 feet (37 m) long.

·  The tallest plant eater was the Brachiosaurus (Giraffatitan brancai). Its head was up to 39 feet (12 m) off the ground.

·  The dinosaur with the thickest skull was the Pachycephalosaurus. Its skull grew up to 8 inches (20 cm) thick.

·  The toothiest dinosaur was the hadrosaurs. It could have over 1,000 teeth and it continually grew new ones.

·  The biggest flying reptile was the Quetzalcoatlus. It had a wingspan up to 39 feet (12 m).

·  The dinosaur with the longest claws was the Therizinosaurus (“reaping lizard”). Its claws were up to 3 feet (1 m) long.

·  The tallest hunter was the Deinocheirus (“horrible hand”). Its head was up to 20 feet (6 m) off the ground.

·  The fastest dinosaur was the Ornithomimus. It could run up to 43½ mph (70 km/h).

·  Stegosaurus had huge upright plates on its back that could grow as large as 30 inches. While scientists do not fully understand the function of these massive plates, they speculate that the stegosaurus could control its body temperature by regulating blood flow through them. A stegosaurus may have also been able to control its skin color this way, to either attract a mate or scare predators. Scientists call this color change “blushing.”

·  The smallest fully grown dinosaur fossil is Lesothosaurus (“Lizard from Lesotho”). It is only the size of chicken. Smaller fossils have been found, but they are of baby dinosaurs.

·  The smallest dinosaur egg ever found was only 3 centimeters long and weighed 75 grams. It is not known what kind of species it came from. The largest dinosaur eggs ever found belong to a meat eater in Asia called segnosaurus (“slow lizard”). The eggs are around 19 inches long.

·  The smartest dinosaur was probably the Troodon (“tooth that wounds”). It had a brain the size of a mammal or bird today. It also had grasping hands and stereoscopic vision.

·  The first known American dinosaur was discovered in 1858 in the marl pits in Haddonfield, New Jersey. Although other fossils were previously found, they were not correctly identified as dinosaur fossils.

·  There was such fierce rivalry between paleontologists Edward Cope and Othniel Marsh to find new dinosaurs fossils that they spawned what became known as the Bone Wars. The fight lasted for over 30 years. Marsh is said to have “won” the wars, in part because he found more fossils and he was better funded.

·  Paleontologists are not perfect. For example, Gideon Mantell (1790-1852) put Iguanodon’s thumb claw on top of its nose. It stayed that way for 40 years. Edward Cope (1840-1897) reconstructed Elasmosaurus (“thin plate”) with its head on the end of its tail. Until recently, Apatosaurus (or Brontosaurus) appeared in museums with the head of Camarasaurus (“chambered lizard”).

·  Current dinosaur fossil “hot spots” include South America (particularly Argentina) and China, where several feathered dinosaurs have been found.

 

General Timeline[7][8]

Date Event
4.6 Billion Years Ago Earth, its moon, and the solar system form.
3.8 Billion Years Ago One-celled life forms develop.
570 Million Years Ago First fish appear.
400-350 Million Years Ago Plants thrive.
350 Million Years Ago Amphibians (cold-blooded animals that live on water and land) appear on land.
330 Million Years Ago Primitive reptiles, the first beings to live completely on land, appear. These would evolve into dinosaurs.
230 Million Years Ago First dinosaurs appear.
220 Million Years Ago Pangaea breaks up; continents first appear.
200-140 Million Years Ago First birds and mammals appear.
125-100 Million Years Ago First flowering plants grow.
110 Million Years Ago Present continents form.
65 Million Years Ago Dinosaurs mysteriously die out. Some mammals, insects, and others survive.
2 million Years Ago First humans appear. They make tools, use fire, and eventually learn to communicate.
30,000 Years Ago Modern humans appear.

 

Dinosaur Firsts

Date Event
1824 William Buckland describes Megalosaurus fossil.
1825 Gideon Mantell describes Iguanodon fossil.
1842 Richard Owen coins the word "Dinosauria."
1858 American paleontologist Joseph Leidy describes the first reasonably complete dinosaur skeleton, near Haddonfield, New Jersey.
1868 English scientist Thomas Huxley first proposed that dinosaurs and birds are related.
1902 Barnum Brown discovers the first fossils of Tyrannosaurus rex at Hell Creek, Montana.
1908 George and Levi Sternberg find the first impression of dinosaur skin, belonging to an Edmontosaurus, in Wyoming.
1923 Roy Chapman Andrews and his crew discover the first dinosaur nest in the Gobi Desert in Mongolia.
1978 Jack Horner finds a Maiasaura “nursery,” the first dinosaur eggs and nests in North America, at Egg Mountain, Montana.
1987 Argentinosaurus, the heaviest known dinosaur, is discovered in Patagonia, Argentina.
1990 Sue, the largest, most complete, and best preserved Tyrannosaurus rex skeleton ever discovered, is found in South Dakota.
1991 Eoraptor, the earliest known named dinosaur, is found in the Valley of the Moon, Argentina.
1993 Giganotosaurus, one of the biggest meat eaters, is discovered in Argentina.
1998 Sinosauropteryx, the first dinosaur found with primitive feathers, is found in China.
1999 Sauroposeidon, the tallest known dinosaur, is found in Oklahoma.
2001 A dinosaur superhighway in China is found containing over 100 footprints.
Paleontologists find a fossil of a nonflying dinosaur that had feathers on its body.

Source: www.wikipedia.org / www.natgeo.com / www.history.com

Possible 'Baby' T. Rex Enters Dinosaurian Debate

Thursday, April 5, 2018

If this is in fact the upper jaw of a baby T. rex, it would be the most preserved and most complete specimen among those ever found in Montana's Hell Creek.  UNIVERSITY OF KANSAS

"Paleontology is a team sport," observes Kyle Atkins-Weltman, a fossil preparator at the University of Kansas. For years now, the school's paleo department has been prospecting the fossil-rich Hell Creek deposits of Montana. In June 2016, Kris Super, another preparator at KU, discovered some tiny bone fragments called "float." They were the tip of one tantalizing iceberg.

The scattered float led KU's team to a set of identifiable bones. Left behind by a mid-sized carnivorous dinosaur, the bounty included pieces of the animal's foot, skull, hips and vertebrae. A partial upper jaw loaded with teeth was easily the most eye-catching item of the bunch.

Removed from Hell Creek during the 2017 field season, the material's now being cleaned and analyzed at the university. The big discovery was announced on Thursday, March 29, 2018.

It's clear that the fossils (which are approximately 66.5 million years old) represent a member of the tyrannosaur family. The question is which species? A press release says the material probably came from a juvenile Tyrannosaurus rex. If this is true, then the poor critter died at a tender age. "We would suspect [it would have been] maybe 6 to 7 years old, possibly 8," says Atkins-Weltman.

Should the animal indeed be a young T. rex, it's part of an exclusive club. Atkins-Weltman told LiveScience that fewer than five "decently preserved juvenile T. rexes" have been found at Hell Creek. He adds that the new specimen would "probably be the most preserved and most complete" specimen among them.

Then again, it might be something else. In 1988, dino expert Robert Bakker and two colleagues looked over the skull of a smallish tyrannosaur that had been dug up in Montana. They claimed it belonged to a new species and named it Nanotyrannus lancensis. Supposedly a smaller cousin of T. rex, this thing would've co-existed with the better-known predator.

Not all paleontologists are convinced. While a few other bones have since been attributed to Nanotyrannus, skeptics argue that these remains — along with that skull — really came from a young Tyrannosaurus rex. In other words, Nanotyrannus may not be a valid genus at all. Like humans, dinosaurs changed shape as they aged. This fact might explain the physical differences between alleged Nanotyrannus bones and other T. rexremains.

"It's reasonable to assume Nanotyrannus could be valid — but we must show it's not just a stage in the life history of T. rex," says KU professor David Burnham. The University owns a lot of material from other T. rexskeletons. Burnham and his Kansas colleagues intend to compare those bones to the new remains. That should help them determine if they've got a juvenile Tyrannosaurus or a mature Nanotyrannus on their hands. And since the new specimen is so complete, analyzing it may bring us closer to putting the entire Nanotyrannus debate to rest.

Source: https://animals.howstuffworks.com

Prehistoric Reptile Pregnant With Octuplets

Thursday, April 5, 2018

Artist's depiction of the pregnant Ichthyosaur, with cutaway revealing embryos. Illustration: Nobumichi Tamura

Palaeontologists have discovered part of the skeleton of a 180 million-year-old pregnant ichthyosaur with the remains of between six and eight tiny embryos between its ribs.

The new specimen was studied by palaeontologists Mike Boyd and Dean Lomax from The University of Manchester. It was collected around 2010 from near Whitby, North Yorkshire and is from the Early Jurassic. The fossil was in the collection of fossil collector, Martin Rigby, who thought the specimen might be a block of embryos. Dean confirmed the suspicion and the specimen was acquired by the Yorkshire Museum, York.

Ichthyosaurs were aquatic reptiles that dominated the Jurassic seas. They gave birth to live young, rather than laying eggs, and did not need to return to land, even to breed. They were carnivores, feeding upon other reptiles, fish, and marine invertebrates such as the squid-like belemnites.

Ichthyosaur fossils are quite common in the UK and often found in British Jurassic rocks. However, only five ichthyosaur specimens from Britain have ever been found with embryos and none with this many. All five were collected from Jurassic exposures in the south-west of England and are between 200-190 million years old. This is the first to be found in Yorkshire. The new specimen is a star attraction in the new major exhibition, Yorkshire's Jurassic World, which recently opened on March 24.

The Jurassic rocks of Yorkshire have produced hundreds of ichthyosaur and other marine reptile skeletons, but have not, until now, yielded any reptilian embryos. The new specimen, as well as being the first embryo-bearing ichthyosaur recorded from Yorkshire, is also geologically the youngest of the British embryo-bearing specimens, being from the Toarcian Stage of the Jurassic, around 180 million-year-old.

The specimen is a small boulder that has been cut in half and polished, which exposes several large ribs (of the adult) and several strings of vertebrae and various indeterminate tiny bones. Boyd and Lomax say there are at least six embryos present, but probably eight.

Mike said: "We also considered the possibility that the tiny remains could be stomach contents, although it seemed highly unlikely that an ichthyosaur would swallow six to eight aborted embryos or newborn ichthyosaurs at one time. And this does not seem to have been the case, because the embryos display no erosion from stomach acids. Moreover, the embryos are not associated with any stomach contents commonly seem in Early Jurassic ichthyosaurs, such as the remains of squid-like belemnites."

Eight different species of ichthyosaur have been documented with embryos. By far, the most commonly found ichthyosaur with embryos is Stenopterygius. Over a hundred specimens of Stenopterygius from Holzmaden and surrounding areas in Germany have been found with embryos, ranging from one to eleven in number.

"The German sites are approximately the same age as the new specimen from Whitby and it is possible that the new specimen is also Stenopterygius, but no identifiable features are preserved in the adult or embryos. Nonetheless, this is an important find." added Dean.

Sarah King, curator of natural science at the Yorkshire Museum, said: "This is an incredible find and the research by Dean and Mike has helped us confirm it is the first example of fossilised ichthyosaur embryos to be found in Yorkshire. Its display in Yorkshire's Jurassic World incorporates the latest digital technology to reveal the embryos and to explain the significance of the discovery. It also allows us to show a softer and more nurturing side to the Sea Dragons which were the top marine predator of their time."


Story Source:

Materials provided by University of ManchesterNote: Content may be edited for style and length.


Journal Reference:

  1. Boyd, M. J. and Lomax, D. R. The youngest occurrence of ichthyosaur embryos in the UK: A new specimen from the Early Jurassic (Toarcian) of YorkshireProceedings of the Yorkshire Geological Society, 2018 DOI: 10.1144/pygs2017-008

    Source: www.sciencedaily.com

Study on Stones Sheds Light on How Dinosaurs Nurtured Eggs

Wednesday, April 4, 2018

Study on stones sheds light on how dinosaurs nurtured eggs

Scientists have worked out the incubation style of dinosaur species by examining the type of sediment their fossilized eggs were found in.

Some are believed to have brooded their eggs, like present-day birds, while others apparently drew on solar, geothermal or fermentation heat to warm their eggs left in sandstone or mudstone.

The researchers from Nagoya University, Hokkaido University and other institutions also studied the distribution of locations where the fossilized eggs have been found.

“In addition to motor capabilities and metabolic capacity, incubating habits may also have been a key factor that affected the dinosaurs’ habitat distribution,” said Kohei Tanaka, a superlative postdoctoral fellow with Nagoya University Museum.

The scientists analyzed the sediment data from about 160 million to 66 million years ago, partly by studying available literature on the topic.

Fossilized eggs of sauropodomorphs, a group of long-necked dinosaurs that included the brachiosaur and measured up to more than 30 meters in length, have been found in sandstone.

That suggests they used to lay eggs in sand and relied on solar or geothermal heat, the researchers said.

Fossilized eggs of hadrosaurs, which looked like platypuses, have been found in mudstone, which is made of solidified soil containing fragments of microorganisms and plants.

They likely relied on heat from the fermentation of plant bodies, the researchers said.

In the meantime, eggs of oviraptorosaurs and troodontids, which resembled ostriches, have been found in equal proportions in mudstone and sandstone.

Their eggs are presumed to have been brooded by parents, regardless of the environment.

Eggs of dinosaur species that relied on solar or geothermal heat have been found only in mid-latitudes between 20 and 50 degrees north.

But fossilized eggs of dinosaur species that either relied on fermentation heat or brooded their eggs have been also found in the Arctic region, such as Siberia.

The research results have been published in Scientific Reports, a British science journal.
 

Source: www.asahi.com

Eocene Monitor Lizard Had Four Eyes: Study

Wednesday, April 4, 2018

Saniwa ensidens had an atavistic pineal eye behind the third eye. Image credit: Senckenberg Research Institute / Andreas Lachmann / Digimorph.org / Nici Keil.

According to a new study, Saniwa ensidens — an extinct monitor lizard that lived in what is now Wyoming 51-49 million years ago (Eocene epoch) — had four eyes, a first among known jawed vertebrates. The third and fourth eyes refer to pineal and parapineal organs, eye-like photosensory structures on the top of the head that play key roles in orientation and in circadian and annual cycles.

“The photosensitive pineal organ is found in a number of lower vertebrates such as fishes and frogs. It’s often referred to as the ‘third eye’ and was widespread in primitive vertebrates,” said lead author Dr. Krister Smith, a researcher with the Senckenberg Research Institute in Germany.

“On the one hand, there was this idea that the third eye was simply reduced independently in many different vertebrate groups such as mammals and birds and is retained only in lizards among fully land-dwelling vertebrates.”

“On the other hand, there was this idea that the lizard third eye developed from a different organ, called the parapineal, which is well developed in lampreys. These two ideas didn’t really cohere.”

“By discovering a four-eyed lizard — in which both pineal and parapineal organs formed an eye on the top of the head — we could confirm that the lizard third eye really is different from the third eye of other jawed vertebrates,” he said.

Dr. Smith and co-authors got the idea that the fossilized lizards might have a fourth eye after other experts came to contradictory conclusions about where the lizard’s third eye was located.

“The first question to explore the ‘wacky’ idea of a lizard with four eyes was, does this unusual feature occur in more than one individual of the same age?” Dr. Smith said.

“We turned to museum specimens collected nearly 150 years ago at Grizzly Buttes as part of the Yale College Expedition to the Bridger Basin, Wyoming. And, it turned out that the answer to their question was yes.”

“CT scans showed that two different individuals of Saniwa ensidens (a fossil sister lineage of the extant genus Varanus) had spaces where a fourth eye would have been, which I certainly did not expect.”

The evidence confirms that the pineal and parapineal glands weren’t a pair of organs in the way that vertebrate eyes are.

The third eye of lizards evolved independently of the third eye in other vertebrate groups, according to the team.

“While there’s nothing mystical about the pineal and parapineal organs, they do enable extraordinary abilities,” Dr. Smith said.

“For instance, they allow some lower vertebrates to sense the polarization of light and use that information to orient themselves geographically.”

“Scientists still have a lot to learn about the evolution of these organs and their functions in living animals.”

The findings were published in the April 2, 2018 issue of the journal Current Biology.

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Krister T. Smith et al. 2018. The Only Known Jawed Vertebrate with Four Eyes and the Bauplan of the Pineal Complex. Current Biology 28 (7): 1101-1107.e2; doi: 10.1016/j.cub.2018.02.021

Source: www.sci-news.com

Jurassic World 2 Theory: The Indoraptor Has Human DNA

Friday, April 6, 2018

Jurassic World: Fallen Kingdom has a new genetically-engineered dinosaur – the Indoraptor – but is what makes this new horror so terrifying human DNA? The Jurassic Park franchise is predicated on John Hammond’s goal to “spare no expense,” so it makes sense that each sequel would push boundaries and explore new avenues to heighten the already-inconceivable notion of living dinosaurs. Unfortunately, the scientists in this series never seem to learn limits.

Since the very first Jurassic Park, the franchise has showcased the evolution of dinosaur hybrids. In the first Jurassic Park, it involved dinosaur and frog DNA; in The Lost World, we saw more physical proof of “life finding a way” with gender mutation and breeding; in Jurassic Park III, audiences get a look at InGen’s abandoned compound, where illegal cloning was taking place; and in Jurassic World, the first official genetically modified hybrid dinosaur not based on a real creature – the Indominus Rex – was introduced.

So, where does a franchise that has reached its fifth entry go from here? How else can the series further explore the dangers of genetic meddling? In the hands of scientists with unlimited resources, the sky is the limit (though in this case, the limit might be humanity itself).

Jurassic Park IV concept art

Before Jurassic World, a direct sequel Jurassic Park 4 was being conceived with screenwriters William Monahan and John Sayles. Both celebrated screenwriters (Monahan had just won an Oscar for The Departed around this time), their concept ultimately turned out to be a major departure from the original trilogy, delving into some daring—if not deranged—territory.

In the first half of the script, there were all the trappings of a traditional Jurassic Park experience: the return of John Hammond, revisiting Isla Nublar, dinosaurs escaping from containment. However, the plot takes a decidedly unexpected turn once a mysterious scientific facility reveals that they’ve successfully spliced together dinosaur and human DNA. The result? Dinosaurs walking on their hind legs, equipped with oversized machine guns. When Amblin Entertainment saw the concept art of these dinosaurs, it reportedly led to them shutting down the project altogether, thus forcing a new creative team to take a crack at the sequel. That said, certain details from the Monahan/Sayles script weren’t completely left on the cutting room floor.

For example, Jurassic World‘s Owen Grady (played by Chris Pratt) may as well be a carbon copy of Jurassic Park 4′s main character, Nick Harris. He’s an ex-soldier tasked with training a group of specialized dinosaurs (only in this case, they’re not velociraptors, but hybrids). Also in that early draft is an active volcano threatening to destroy the island, something that is – albeit with differing motivations – return in Fallen Kingdom. There’s also hints of a secret scientific facility on the island, which again mirrors an underground base from Jurassic Park 4 tasked with creating a new hybrid species of dinosaur. The script may be dead, but its ideas live on.

In Jurassic World, the Indominous Rex was never just a theme park attraction. It was designed to boost sales at the Jurassic World theme park, but its head creator Dr. Henry Wu made an under-the-table deal with InGen’s Security Division commander Vic Hoskins for military purposes. So, from the get-go, it was little more than a weaponized monster. In Fallen Kingdom, these morsels of information will undoubtedly come to light. Wu is last seen leaving the island with some hybrid dinosaur embryos, and before his death, Hoskins acknowledges the benefit of a smaller I-Rex—which naturally leads to the creation of the Indoraptor.

This is nothing new. The finer details are, sure, but the franchise’s overall theme has remained consistent: humans playing God, and failing. No matter the level of meddling, the results are always the same; dinosaurs go out of control and those unlucky to get in the way pay the price for scientific meddling. Despite how innovative and brilliant they all might be, they never learn. By Jurassic World, Wu is little more than Dr. Frankenstein, splicing together the “best” bits and pieces of various dinosaurs and animals to create what ultimately turn out to be abominable killing machines. What’s worse is that, despite recurring repercussions on massively violent scales, he persists, showing no signs of restraint.

With those pieces in place – and it known there are a lot of spoilers hidden by the trailers – there’s definitely the grounding to suggest that the Indoraptor is a little more “familiar”.

Source: www.screenrant.com

Prehistoric Trackways a Treasure Trove of Unique Resources

Monday, April 9, 2018

What was life like when all continents were together in one super continent? The answer to this question is complex. However, there’s a special place that holds the answer to this and many other paleontological questions. It’s called the Prehistoric Trackways National Monument and it’s accessible for the public to explore and enjoy.

The Bureau of Land Management (BLM) is the proud custodian of this diverse and fascinating landscape just northwest of Las Cruces and Colin Dunn is the BLM paleontologist knowledgeable about its unique public land resources.

Every month on a Saturday morning, Dunn leads a three-hour hike to the Robledo Mountains. His purpose is to expose and educate the public to the monument’s important geologic history and significant paleontological and recreation features.

The hike to the Discovery Site takes visitors to the original deposit of Paleozoic Era fossilized “trackways” – footprints of numerous amphibians, reptiles, insects and plants.  While hiking the terrain, Dunn discusses the importance of this site to the scientific study of the early Permian Period and the associated animal behaviors and paleo-environments of the time, predating dinosaurs.

“The preservation quality and fossil diversity gives us a real snapshot into the paleoecosystem, more than just bones alone could do,” he said.

For the Site Flood hike, Dunn takes hikers to an area in the monument containing petrified wood. Along the way, visitors learn about the numerous marine invertebrates that lived in the ancient oceans over 280 million years ago, as well as shallow-water trackmakers that left their mark on the nearby tidal flats.

For both hikes, Dunn tells the story of how the “prehistoric trackways” was first discovered in 1987 by Jerry MacDonald, citizen-scientist of Las Cruces, and what it took to excavate and curate a unique collection of 2,500 slabs of fossilized trackways.  The collection is now part of the New Mexico Museum of Natural History and Science in Albuquerque, the Federal Repository for fossils in New Mexico.  However, some of these trackways are on display here in Las Cruces, at the Museum of Nature and Science

According to Dunn, The monument serves as a special outdoor laboratory for the public to learn about paleontology and geology in their backyard.

”The museums have excellent examples of the fossils found here, but there is something to be said from seeing them in their original geological context,” he said. “Many of the tracks and traces are very subtle, and until I point them out, most people just walk past them.”

The Prehistoric Trackways National Monument was established by Congress in 2009 to conserve, protect and enhance the 5,280 acres of unique and national-important paleontological, scientific, educational, scenic and recreational resources and values.

For more information on the monument and the monthly hikes, visit the BLM Las Cruces District office at 1800 Marquess Street or call 575-525-4300.  In addition, the BLM website www.blm.gov/visit/ptnm provides interactive maps on the monument’s recreation resources.

Source: www.lcsun-news.com

Liberal MLA Calls on Province to Save B.C.'s Largest Dinosaur Collection

Sunday, April 1, 2018

A dinosaur skull that is roughly 75 million years old is among the many ancient discoveries made in the region around Tumbler Ridge, B.C. (Charles Helm)

Mike Bernier argues the dinosaur discoveries in northeastern B.C. outshine Drumheller, Alta.

A B.C. Liberal MLA is calling on the province to step in after a dinosaur museum in Tumbler Ridge closed its doors this month, arguing it has the potential to be Canada's premier dinosaur display.

The Peace Region Paleontology Research Centre and Dinosaur Discovery Gallery in Tumbler Ridge idled its operations and sent layoff notices to staff after failing to secure a $200,000 funding request from the District of Tumbler Ridge, which has a population of about 2,000 people.

Mayor Don McPherson said the decision was driven by a desire to have the museum work more closely with the local geopark society, which manages Tumbler Ridge's status as a UNESCO-recognized destination for its unique geological heritage.

McPherson also said there were concerns about the fact the district has been funding the museum for over a decade with little support from other levels of government.

"We've been funding this museum to the tune of over $2 million," he said.

'It would be a huge loss for the province'

Mike Bernier, the Liberal MLA representing Tumbler Ridge, said he's been advocating for the province to start funding the museum in recognition of its unique collection of dinosaur bones and fossils, the largest in B.C.

"I believe that it's time the province steps in and helps, instead of the local government having all the burden," Bernier told CBC Daybreak North host Carolina de Ryk.

"It would be a huge loss for the province."

Discoveries made through the museum and research centre include: the northernmost prints of brontosaurus; the only Tyrannosaurus trackway in the world; the only known footprints of the carnivorous Therizinosaur; and the most complete dinosaur skeleton ever found in the province.

Museum curator Rich McCrae said he's not sure there are any other facilities in B.C. that could take on Tumbler Ridge's collection, meaning many of the items could wind up in other parts of the world if the museum shuts down. 

Bernier said he believes with provincial backing, the museum could be a tourism draw that outshines what's on display at the Royal Tyrrell Museum in Drumheller, Alta.

"This is not just a typical museum that a lot of communities have to showcase their history. This has global significance," he said.

​"The paleontological finds that Tumbler Ridge has far outstretches what Drumheller has. We just need an opportunity to be able to showcase that."

Problems 'best resolved locally': province

Bernier said he has raised the issue with the Ministry of Tourism, Arts and Culture, and hoped the current closure would add some "urgency" to those discussions.

However, a spokesperson for the ministry said it had not received any request from the museum itself to assist in its funding shortfall, adding it "appears to be the result of a local issue" that is "likely best resolved locally."

McPherson said the district of Tumbler Ridge isn't opposed to funding the museum, but council wants it to first reach a memorandum of understanding with the geopark society as to how the two entities will work together.

Representatives for the museum board and the geopark society said negotiations on that memorandum of understanding are in progress.

Source: www.cbc.ca

Dinosaurs: How Long Did They Live?

Sunday, April 8, 2018

 Predators like Tyrannosaurus rex grew fast and died young. Photograph: Louie Psihoyos/Corbis

Carnivores may have lived to 30 years, herbivores far longer.

It isn't easy to tell from dinosaurs' fossilised remains how long they lived. "Traditional" estimates based on slow, reptilian growth rates, combined with the enormous size of dinosaurs, led scientists to conclude it could be up to several hundred years. However, palaeontologists today believe that dinosaurs grew much more quickly, rather like birds and mammals.

Dinosaur bones grew like those of other vertebrates, by adding new bone matter to the outside of the bone. Because of annual variation in temperature or the availability of food, periodically bone growth would slow down, and a thin layer of avascular bone would form a ring or "growth line" in much the same way that tree trunks do. By taking thin slices of bones, these rings can be viewed under a polarised light source. Counting the rings can give an idea of the dinosaur's age at death.

Growth lines in dinosaur bones were first observed in 1983 in the study of Late Jurassic sauropod bones called Bothriospondylus, possibly from the herbivorous brachiosaur family, which was discovered more than a century earlier. The study caused estimates of its age to be revised, and it is now reckoned to have died at the age of 43, when only half way to attaining its full adult length of 15-20 metres.

According to Dr John Nudds, a palaeontologist at the University of Manchester: "If you compare dinosaurs to present-day animals, we might expect that the very large herbivores - things like brachiosaurs and Diplodocus, which were comparable in size to an elephant - would have lived, therefore, for 70-80 years; maybe a bit more. Whereas the smaller, meat-eating dinosaurs would have been more comparable to some of today's larger birds, to which they are closely related. If you think of something like an eagle or raven, they live for 20-30 years, and that would probably have been the lifespan of a T. rex."

The largest and best-preserved T. rex, in the Field Museum of Chicago, is thought to have lived to almost 29 years, although it would have achieved adult size after 20 years. "Sue" is 12 metres long from head to tail, and estimated to have weighed around seven tonnes, underlining the rapid growth rate of such dinosaurs during their (relatively) short lives.

The growth lines also offer a guide to a dinosaur's growth rate at different stages of its life. It is now understood that most dinosaurs grew for a large part of their lives, with a particularly rapid spurt during adolescence.

Did you know?

In the late 1990s, two adult and one juvenile Camarasaurus specimens were found together in the United States, indicating that these sauropods travelled in family groups and possibly herds. It is thought that some dinosaurs may have migrated significant distances, notably those living near the Earth's poles, where food supplies were seasonal. Suggestions of how far they travelled vary, but one recent study estimated large sauropods might have made an 1,800-mile round trip each year.

Source: www.theguardian.com / 2009

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