nandi's blog

Giant Triassic Ichthyosaur is One of Biggest Animals Ever

Thursday, April 12, 2018

Giant ichthyosaurs Shonisaurus. Image credit: Nobumichi Tamura.

According to a study released this week in the journal PLoS ONE, an isolated bone from the lower jaw of a prehistoric marine reptile found in Somerset, UK, belongs to one of the largest animals ever.

 

Fossil collector Paul de la Salle found the 205-million-year-old (Late Triassic epoch) specimen on the beach at Lilstock, Somerset, in May 2016.

Paleontologists Dean Lomax from the University of Manchester and Professor Judy Massare of SUNY College at Brockport identified it as an incomplete bone — called a surangular — from the lower jaw of a giant ichthyosaur.

The researchers estimate the length of this specimen’s body would have been up to 85 feet (26 m) — almost the size of a blue whale.

They also compared the specimen with several ichthyosaur species, including the largest ichthyosaur known — the shastasaurid Shonisaurus sikanniensis, which is 69 feet (21 m) long.

They found similarities between the new specimen and Shonisaurus sikanniensis which suggest the Lilstock bone belongs to a giant shastasaurid-like ichthyosaur.

“As the specimen is represented only by a large piece of jaw, it is difficult to provide a size estimate, but by using a simple scaling factor and comparing the same bone in Shonisaurus sikanniensis, the Lilstock specimen is about 25% larger,” the paleontologists said.

Other comparisons suggest the Lilstock ichthyosaur was at least 65-82 feet (20-25 m).

“Of course, such estimates are not entirely realistic because of differences between species,” Lomax said.

“Nonetheless, simple scaling is commonly used to estimate size, especially when comparative material is scarce.”

In 1850, a large bone was described from the Late Triassic (208 million years old) of Aust Cliff, Gloucestershire, UK.

Four other similarly incomplete bones were also found and described. Two of them are now missing and presumed destroyed.

They have been identified as the limb bones of several dinosaurs (stegosaurs and sauropods), indeterminate dinosaurs and other reptiles.

However, with the discovery of the Lilstock specimen, this new study refutes previous identifications and also the most recent assertion that the Aust bones represent an early experiment of dinosaur-like gigantism in terrestrial reptiles. They are, in fact, jaw fragments of giant, previously unrecognized ichthyosaurs.

“One of the Aust bones might also be an ichthyosaur surangular. If it is, by comparison with the Lilstock specimen, it might represent a much larger animal,” Lomax said.

“To verify these findings, we need a complete giant Triassic ichthyosaur from the UK — a lot easier said than done.”

_____

D.R. Lomax et al. A giant Late Triassic ichthyosaur from the UK and a reinterpretation of the Aust Cliff ‘dinosaurian’ bones. PLoS ONE 13 (4): e0194742; doi: 10.1371/journal.pone.0194742

Source: www.sci-news.com

Anyone Want to Buy a Dinosaur? Two on Sale in Paris

Wednesday, April 11, 2018

A worker assembles the bones of a diplodocus, one of two dinosaur skeletons being sold at auction in Paris on Wednesday

The skeletons of an Allosaurus and a Diplodocus are up for auction in Paris this week, marketed as hip interior design objects—for those with big enough living rooms.

"The fossil market is no longer just for scientists," said Iacopo Briano of Binoche et Giquello, the auction house that is putting the two dinosaurs under the hammer on Wednesday.

"Dinosaurs have become cool, trendy—real objects of decoration, like paintings," the Italian expert told AFP, citing Hollywood actors Leonardo DiCaprio and Nicolas Cage as fans of such outsize prehistoric ornaments.

Cage, however, did hand back the rare skull of a tyrannosaurus bataar, a close cousin of T. rex, that he bought in 2007 after it was found to have been stolen and illegally taken out of Mongolia.

Dinosaur bones are increasingly gracing collectors' cabinets, with another huge skeleton, that of a theropod, expected to fetch up to 1.5 million euros ($1.84 million) when it goes up for auction in June.

Chinese buyers

"For the last two or three years the Chinese have become interested in palaeontology and have been looking for big specimens of dinosaurs found on their soil, for their museums or even for individuals," Briano said.

The new buyers are now bidding against multinational corporations as well as ultra-rich Europeans and Americans, the "traditional" buyers of dinosaur skeletons, Briano added.

In 1997, McDonald's and Walt Disney were among donors stumping up $8.36 million to buy Sue—the most complete and best preserved Tyrannosaurus rex ever found—for the Field Museum of Natural History in Chicago.

"Millions of people come to see it, it's incredible publicity for companies," said Eric Mickeler, a natural history expert for the Aguttes auction house.

Palaeontologists acknowledge that many fossils that go on the block are of limited scientific interest, but important specimens do go up for auction and can, as in Sue's case, be bought through acts of patronage.

Dinosaur skeletons, including the two being auctioned this week, are increasingly being sought as interior design objects, in particular by Chinese buyers

The market remains small and "isn't for everybody", Mickeler said.

Only around five dinosaurs are put up for auction around the world every year.

'People like the teeth'

The allosaurus which goes on sale Wednesday, among 87 lots of natural artefacts, is considered "small" at 3.8 metres (12.5 feet) long.

It is expected to fetch up to 650,000 euros, while the diplodocus—despite being bigger at 12 metres long from nose to tail—has a guide price of 450,000 to 500,000 euros.

Carnivores like the allosaurus often fetch more than herbivores.

"People like the teeth," Mickeler said.

The price also goes up if the skeleton shows traces of a fight or an incurable illness, as well as if it is considered rare, has a high percentage of verified bones, or a particularly impressive skull.

"We recently sold a very beautiful piece to a Venetian family, they have a magnificent big room in which the dinosaur is perfectly at ease," Briano said.

But Ronan Allain, a palaeontologist at the Natural History Museum of Paris, denounced "completely nonsensical" prices.

"It's the luxury world, it's not for people like us," he said.

"We could decide to buy it pre-emptively, but for the theropod, for example, that would mean shelling out more than a million," he said.

Source: https://phys.org

New Study Resolves the Mystery of an Enigmatic Triassic Reptile

Tuesday, April 10, 2018

Scientists from the University of Bristol have re-examined the fossilised remains of a Triassic reptile, currently housed in two separate collections on each side of the Atlantic, and have discovered it is a brand-new kind of beast.

The remains of the reptile, which lived 200 million-years-ago were discovered some decades ago in a South Gloucestershire quarry.

This species, closely related to the living Tuatara from New Zealand, was originally described as Clevosaurus latidens in 1993 by the British paleontologist Nicholas Fraser, referring it to the genus Clevosaurus, already known by many species in the Late Triassic of the south-west of England and South Wales, and elsewhere in the world.

The conundrum was that other species of Clevosaurus were carnivores, whereas the teeth of this beast showed it ate plants.

However, the key fossils are housed in two different collections in the United States and Scotland, and no attempts had been made to re-examine the fossils until now.

The Late Triassic rhynchocephalian Clevosaurus latidens Fraser, 1993 is known from the fissure deposits of Cromhall Quarry, England. Many studies have questioned its referral to the genus Clevosaurus Swinton, 1939 and some phylogenetic analyses suggest a close relationship with herbivorous rhynchocephalians. We re-examine the type specimens and referred material of C. latidens to elucidate its taxonomic identity. Additionally, we provide new phylogenetic analyses of the Rhynchocephalia using both parsimony and Bayesian approaches. Our taxonomic review and both phylogenetic analyses reveal that C. latidens is not referable to Clevosaurus, but represents a new genus. We reassess C. latidens and provide an amended diagnosis for Fraserosphenodon new genus. Both parsimony and Bayesian analyses recover similar topologies and we propose formal names for two higher clades within Rhynchocephalia: Eusphenodontia new infraorder and Neosphenodontia new clade. UUID: http://zoobank.org/65f29bd1-47e3-4a73-af8c-9181c19319e4

Lead author Jorge Herrera-Flores from the University of Bristol's School of Earth Sciences, said: "The restudy of the fossils confirmed our previous suspicions that this species was not related to the carnivorous Clevosaurus.

"It clearly represents a new genus of herbivorous rhynchocephalian, and we are pleased to call it Fraserosphenodon, in honour of Nick Fraser, who first found it, and is now Head of Natural Sciences at the National Museum of Scotland in Edinburgh."

Co-author, Dr. Tom Stubbs, added: "We confirmed the uniqueness of the species by carrying out various numerical analyses of relationships.

"This showed that Fraserosphenodon is a much more advanced rhynchocephalian than Clevosaurus."

Co-author Armin Elsler said: "These Triassic fossils are of huge interest.

"They are close relatives of the living Tuatara, a kind of living fossil, found today only on some islands around New Zealand. We need to understand more about the evolution of this rare and endangered species."

Professor Mike Benton, Jorge's Ph.D. supervisor, added: "I'm delighted we could name this after Nick Fraser, my old classmate at the University of Aberdeen.

"Nick has done great work on Triassic  reptiles, including the rhynchocephalians, from his time in Aberdeen, but also as curator at the Virginia Museum of Natural History, and now in Edinburgh."

More information: Jorge A. Herrera-Flores et al. Taxonomic reassessment of Clevosaurus latidens Fraser, 1993 (Lepidosauria, Rhynchocephalia) and rhynchocephalian phylogeny based on parsimony and Bayesian inference, Journal of Paleontology (2018). DOI: 10.1017/jpa.2017.136

Provided by: University of Bristol

Source: https://phys.org

Newly Found Fossils Go On Show In Dinosaur Museum In Fukui

Monday, April 9, 2018

A complete skeleton of a Tsintaosaurus is displayed on March 17 at a special exhibition at the Fukui Prefectural Dinosaur Museum in Katsuyama, Fukui Prefecture. (Ryo Kageyama)

For dinosaur buffs wanting to see the latest finds, the Fukui Prefectural Dinosaur Museum here is holding a special exhibition showcasing fossils newly discovered in fiscal 2017.

The special exhibition, titled “Excavation 2017,” started March 17. It will run through May 6.

The museum is displaying new fossils found from April 1, 2017, to the end of March 2018 in the series of the fourth excavation between fiscal 2013 and 2018.

Featured fossils include rocks in which the teeth of ankylosauria and the bone fossils of ornithopods have been concentrated.

In the fiscal 2017 excavation, more than 4,000 fragments of vertebrate animals were found. Of these, more than 100 fossils of dinosaurs have been lined up for the special show.

In addition to the authentic fossils, about six complete skeletons related to fossils discovered in Katsuyama are being shown. They include the plant-eating Fukuisaurus, large ornithopod Tsintaosaurus, and a new kind of ankylosauria, “Jinyunpelta,” which was just named in February and will be put on display from the end of March.

On the same day of the start of the exhibition, a 16-meter-tall monument of Rainbow Saurus, the museum’s icon, was unveiled in front of the museum after repair work on it was completed. It was first displayed in 2000.

The fee for the special exhibition is included with regular museum admission of 260 yen ($2.45) for elementary and junior high school students, 410 yen for high school and college students and 720 yen for adults.

Source: www.asahi.com

Radical Plant Hypothesis Blames Dinosaur Extinction on 'Biotic Revenge'

Saturday, April 7, 2018

A small coelurosaur, a feather-tailed dinosaur that lived 99 million years ago, approaching a resin-coated branch on the forest floor.  CHUNG-TAT CHEUNG

The dinosaurs that reigned between 66 and 247 million years ago were massive — some even heavier the space shuttle Endeavour. It seems fitting that they’d meet their end at the hands of a force as powerful as an asteroid and the catastrophic volcanic activity that followed. But a sneakier, more sinister culprit was already wreaking havoc on the dinosaurs long before that asteroid pummeled into the Yucatan Peninsula, evolutionary psychologists argued on Tuesday. In their radical new study, they place the blame on toxic plants.

In the paper, published in the February edition of Ideas in Ecology and Evolution, the University of Albany’s Gordon Gallup, Ph.D. and the University of Baltimore’s Michael Frederick, Ph.D. assert that food poisoning killed the dinosaurs long before the asteroid hit. They call their idea the “biotic revenge” hypothesis.

“Since the spread of toxic plants occurred slowly, that [the hypothesis] is consistent with recent evidence showing that dinosaurs began to disappear millions of years before the asteroid impact and continued to go extinct for millions of years later,” Gallup, a psychology professor at the University at Albany, tells Inverse. “Thus, dinosaurs may have gone extinct because of a simple psychological deficit.”

According to this hypothesis, large, herbivorous dinosaurs ate huge quantities of plant life, including the first toxic angiosperms, which, in turn, gave the dinosaurs great gastrointestinal distress. But because they hadn’t yet figured out taste aversion — that is, learning not to go back to the heinous place last gave you food poisoning — they continued to eat the toxic plants, eventually consuming harmful and lethal doses. This effect of their psychological deficit, they write, “placed additional stress on the species” and “may have done particular damage to dinosaurs” before the asteroid arrived.

The idea of biotic revenge fits in with the increasingly accepted idea that dinosaurs were already in decline millions of years before their semi-final extinction. The fossil record indicates that, before the end of the Cretaceous Period, there already was a slump in dinosaur populations and an increase in the diversity of birds. When Gallup learned that the first toxic plants appeared in the fossil record at about the same time dinosaurs began to go extinct, it dawned on him that this gradual extinction may be linked to the angiosperms.

“The intriguing feature of evolutionary theory,” says Gallup, “is that it enables you to think about things outside the box.”

To back up this claim, Gallup and Frederick examined studies on development of taste aversion among animals that outlived the dinosaurs. Birds, which are thought to have evolved from small meat-eating dinosaurs like velociraptors. Previous studies have shown that present-day birds are capable of learning food aversions, though they do so by sight rather than taste: For example, birds know bright orange monarch butterflies are filled with milkweed toxins, so they’ve learned to avoid them. Gallup and Frederick argue that this psychological ability may have helped birds avoid the fate of other dinosaurs.

They also reevaluated research on crocodilians — which share a common ancestor with dinosaurs and are the closest living relative of birds — that had been conducted by Gallup in 1987, showing that some species didn’t have the capacity for learned taste aversion. By inducing sickness in a group of caimans to see whether they’d associate illness with certain types of foods, they discovered that the caimans were always willing to eat anything, whether it made them sick or not.

This inability to learn taste aversion is a trait that the study authors think could have been shared by dinosaurs, but a lucky quirk of habitat saved them from extinction. The reason that crocodilians didn’t go extinct, they write, is “that being aquatic carnivores, they never had to cope with the problems posed by consuming toxic terrestrial plants.”

Gallup and Frederick are well aware that this unusual hypothesis may make skeptical paleontologists ask: What do a couple of psychologists know about dinosaur extinction? Rather than scoff at their theory, however, they hope paleontologists will help them evaluate the fossil record further in order to test their hypothesis with empirical evidence.

So did early toxic plants enact a biotic revenge? More evidence is necessary to say so definitively. But if dinosaurs really were munching down toxic plants despite extreme belly pain, it’s theoretically possible that their fatal psychological deficit pushed them toward extinction. The asteroid, says Gallup, “certainly played a factor,” but it’s plants that may have “placed severe strain on the species.”

Source: www.inverse.com

Did You Know “Jurassic Park” only Had 6 Minutes of CGI Runtime?

Friday, April 6, 2018

For all its intensity and impressive showing, the film Jurassic Park only had six total minutes of CGI runtime. When you really think about it though six minutes is an eternity in the scope of a film for any scene to play out. In some scenes you become so invested that an entire half hour or more can pass by without you even knowing about it. But in Jurassic Park, despite the impressive nature of the dinosaurs and their rampage throughout the park, the CGI was kept to a minimum since Steven Spielberg didn’t think that it would hold to intense scrutiny quite as well as the animatronic dinos would.

Most of the models within the film are very real, and were used in more than one scene throughout the movie. Some of them were even conceptualized as suits that would be worn by actors. But the CGI is something that people can look at and discern from the real surroundings since in truth it’s not really happening in real time on the set. If you look behind the scenes on any film that uses CGI, and there are a lot of them, you’ll see that the actors are usually being directed to follow a target with their eyes so as to show that they’re watching something pass by, come closer, and so on and so forth. Creating animatronic versions of everything would be an intense and very costly venture for any film set, but Jurassic Park made it work by integrating the story line with the dinosaurs so well that people were waiting with anticipation to see the creatures come bursting out of the foliage and scare the living daylights out of them.

That meant a lot of build up to the movie, which in turn meant that sound and visual effects could be used quite often to denote such a thing as the T. rex clomping its way forward. The impact tremors that you hear in the movie are not realistic since if you study anything concerning the effect of impact tremors and the likelihood of them traveling that far, you might find out that the T. rex was in fact capable of making such tremors. But given that it’s an early warning system and the T. rex is a hunter, it would be foolish of such a creature to do so. That was put in more for effect than anything, and the idea of not moving and having the T. rex lose them played more to the likelihood that the humans would escape without being chomped in half. In reality, the T. rex has been said to have a very keen sense of smell, so every last one of them would have been eaten if reality had been a factor in this movie.

But it’s for entertainment, so the paleontology lesson took a back seat at times to the wonders of Hollywood magic which is pretty normal. Spielberg did manage to listen to those paleontologists that he consulted with and that’s why the movie was as good as it was.

Source: www.tvovermind.com

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

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