Discover extinct lizard-like reptiles that lived among the dinosaurs 150 million years ago

An extinct reptile that lived among the dinosaurs 150 million years ago has been discovered in the Badlands of Wyoming.

The new species, called Opisthiamimus gregori, measured about 6 inches from nose to tail and would be twisted into the palm of an adult human hand.

They lived alongside dinosaurs like Stegosaurus and Allosaurus in North America 150 million years ago, and likely survived on a diet of insects and other invertebrates, according to researchers from the Smithsonian National Museum of Natural History.

This small creature is believed to belong to the same ancient lineage as the New Zealand tuatara, the last living member of a group that has been almost completely replaced by lizards.

“What’s important about the tuatara is that it represents this enormous evolutionary story that we are fortunate enough to learn about at the very end of it,” said lead author Dr. Matthew Carano, of the Smithsonian Institution.

“Although it looks like a relatively simple lizard, it exemplifies a whole evolutionary saga going back more than 200 million years.”

An artistic interpretation of a newly discovered extinct species of lizard-like reptile belonging to the same ancient lineage as the living tuatara of New Zealand. The newly discovered Opisthiamimus gregori preyed on a now-extinct aquatic insect (Morrisonnepa jurassica), while in the background the predatory dinosaur Allosaurus jimmadseni guards its nest.

The discovery comes from a few specimens–including a very complete and well-preserved fossil skeleton–found near the Allosaurus’ nest in the Morrison Formation of northern Wyoming.

While it looks like a lizard, it’s actually a rhynchocephalian – something that differed from lizards at least 230 million years ago.

At the height of the Jurassic period, rhynchocephalians were found almost all over the world, and they came in large and small sizes, occupying ecological roles ranging from aquatic fishermen to huge plant cutters.

But for reasons that are still not fully understood, both rhynchocephalians disappeared as lizards and snakes grew to become the most common and most diverse reptiles around the world.

Now the only remaining member of this ancient animal order is the New Zealand tuatara, which is about five times longer than Opisthiamimus gregori and looks like a mighty iguana.

Features that distinguish it from lizards include teeth fused to the jawbone, a unique chewing motion that slides the lower jaw back and forth like a saw blade, a lifespan of over 100 years, and endurance of cold climates.

Fossil skeleton of a new lizard-like reptile Opisthiamimus gregori.  The fossil was discovered in the Morrison Formation of the Bighorn Basin, north-central Wyoming, and dates to the late Jurassic period, about 150 million years ago.

Fossil skeleton of a new lizard-like reptile Opisthiamimus gregori. The fossil was discovered in the Morrison Formation of the Bighorn Basin, north-central Wyoming, and dates to the late Jurassic period, about 150 million years ago.

The world’s first gliding reptile evolved 260 million years ago

A new study has found that the world’s first gliding crawler evolved 260 million years ago thanks to changes in the tree’s canopy.

Researchers at the French National Museum of Natural History, Paris, and the Staatliches für Naturkunde Karlsruhe, Germany, have compiled fossils of Coelurosauravus elivensis, an extinct species of reptile with a name meaning ‘hollow grandfather lizard’.

The remains indicate that the species evolved to produce a patagium – a wing-like membrane on each side – to facilitate flight.

This allowed it to adapt from a habitat where trees moved from a densely crowded place to a place where there are more separated trees.

Paleontologists mostly know about Rhynchocephalians from small fragments of their jaw and teeth, because their weak bones were often destroyed either before they were fossilized or as they emerged from an eroded rock formation today.

However, one of the fossils found in the Morrison Formation is almost completely complete, with the exception of the tail and parts of the hind legs, making it exceptionally rare.

The researchers have now performed a cross-sectional survey of the fossil to create a three-dimensional representation of the specimen with a resolution of less than a millimeter.

Then they reassembled the numbered skull bones — some of which had been crushed, misplaced or lost on one side — using software to eventually create a near-complete 3D reconstruction.

The reconstructed skull gave researchers an unprecedented look inside the head of a Jurassic reptile – revealing that it may have eaten hard-shelled prey such as beetles or water bugs as well as insects.

Co-author David Demar, co-researcher, added: “Such a complete specimen has tremendous potential for making comparisons with fossils collected in the future and for identifying or reclassifying specimens already in a museum drawer somewhere.

“With the 3D models that we have, at some point we can also do studies that use software to look at the mechanics of this creature’s decoding.”

Now the only remaining rhynchocephalian species is the New Zealand tuatara (pictured), which is about five times longer than Opisthiamimus gregori and looks a bit like a mighty iguana.

Now the only remaining rhynchocephalian species is the New Zealand tuatara (pictured), which is about five times longer than Opisthiamimus gregori and looks a bit like a mighty iguana.

Opisthiamimus gregori has now been added to the collections of the Smithsonian Museum, where it will remain available for future study.

It may help researchers figure out why tuatara survived all that was left of the rhynchocephalians, while lizards scattered around the planet.

“These animals may have disappeared partly because of competition from lizards but perhaps also because of global changes in climate and habitat change,” Carano said.

“It’s amazing when you have the dominance of one group giving way to another over evolution time, and we still need more evidence to explain exactly what happened, but fossils like this is how we’re going to put it together.”

The researchers named the new species after museum volunteer Joseph Gregor.

He spent hundreds of hours meticulously scraping and sculpting bones from a block of stone that caught the eye of Museum Fossil curator Pete Kroehler in 2010.

Dr Carano said: “Pete is one of those people who has kind of an X-ray vision for this kind of thing.

He noticed two small pieces of bone on the side of this block and marked it to be turned back without any real idea of ​​what was inside. As it turns out, he won the jackpot.

Opisthiamimus is described in the Journal of Systematic Paleontology.

How did dinosaurs span about 66 million years ago

Dinosaurs ruled and dominated the Earth about 66 million years ago, before suddenly becoming extinct.

The third Cretaceous Extinction event is the name given to this mass extinction.

It was believed for many years that the changing climate destroyed the food chain of the mega reptiles.

In the 1980s, paleontologists discovered a layer of iridium.

This is a rare element on Earth but is found in huge quantities in space.

When this date was dated, it precisely coincided with the disappearance of the dinosaurs from the fossil record.

A decade later, scientists discovered the huge Chicxulub Crater at the tip of the Mexican Yucatan Peninsula, which dates back to the period in question.

The scientific consensus now says that these two factors are related, and both may have been caused by a massive asteroid collision with Earth.

With the expected magnitude and speed of impact, the collision would have caused a massive shock wave and likely triggered seismic activity.

The fallout would have created plumes of ash that likely covered the entire planet and made surviving dinosaurs impossible.

Animals and other plant species had a shorter period of time between generations which allowed them to survive.

There are several other theories as to the reason for the demise of these famous animals.

One early theory was that small mammals eat dinosaur eggs and another suggests that poisonous angiosperms (flowering plants) kill them.

Related Posts

Leave a Reply

Your email address will not be published.