Scientists have exposed new clues in a curious fossil in Nevada, a graveyard for dozens of giant marine reptiles. Instead of a mass death as suspected, it may have been an old maternity ward where the creatures came here to give birth.
He is known for his fossils of giant ichthyosaurs, reptiles that ruled the ancient seas and can reach the length of a school bus. The creatures, the so-called means lizard fish, were underwater predators with large paddle-shaped fins and long full jaws. of teeth
Since the Nevada ichthyosaur bones were excavated in the 1950s, many paleontologists have studied how it is possible that all those creatures died together. Now, researchers have proposed another theory in a study published Monday in the journal Current Biology.
The scientists said they would possibly have answered a “question that has disappointed paleontologists for more than half a century. “
“Several pieces of evidence point to an argument here: that this is a position where giant ichthyosaurs came here to give birth,” said co-author Nicholas Pyenson, curator of fossil marine mammals at the Smithsonian National Museum of Natural History.
New through a team of scientists, adding some from the Smithsonian National Museum of Natural History, suggests. . .
Once a tropical sea, the site, a component of Berlin’s Ichthyosaur State Park in Nevada, now sits in a dry, dusty landscape near a deserted mining town, said leader Randy Irmis, a paleontologist at the University of Utah.
To get a better look at the skeletons, which feature plate-sized vertebrae and fin bones as thick as rocks, the researchers used three-dimensional scanning to create a detailed virtual model, Irmis said.
They know fossils of at least 37 ichthyosaurs scattered throughout the region, dating back about 230 million years. The bones were preserved in other layers of rock, suggesting the creatures may have died many thousands of years apart rather than all at once, Pyenson said.
A first break came when researchers detected tiny bones among the large adult fossils and discovered they belonged to embryos and newborns, Pyenson said. The researchers concluded that the creatures visited the site in teams when they gave birth, like today’s sea giants. The fossils are believed to have originated from mothers and calves that died there over the years.
“Finding a position to give birth from a position where you can only feed is not unusual in the modern world: among whales, among sharks,” Pyenson said.
Other clues have some of the past explanations.
Testing of chemicals on earth revealed no symptoms of volcanic eruption or significant changes in the local environment. And geology has shown that reptiles are preserved on the ocean floor quite far from shore, meaning they probably didn’t die in a mass stranding. Irmis said.
The new study offers a credible explanation for a site that has puzzled paleontologists for decades, said Dean Lomax, an ichthyosaur specialist at the University of Manchester in England who was not involved in the study.
The case may not be completely closed yet, but the study “is really helping to know a little bit more about this desirable site,” Lomax said.
Earlier this year, paleontologists in the United Kingdom announced the discovery of the fossilized remains of an “incredibly rare ichthyosaur that is just about 33 feet long and about 180 million years old. The fossil, which researchers say is “very well preserved,” has been called the “paleontological discovery of a lifetime. “