Earth’s oldest ocean giant was a reptile with an eight-foot skull | Smart News

Although ichthyosaurs and whales never existed at the same time, they both evolved from species that walked the land and moved to the sea.
Stephanie Abramowicz, courtesy of Los Angeles County Museum of Natural History

Back when dinosaurs ruled the land, giant marine reptiles called ichthyosaurs ruled the sea. They are known as the planet’s first giants, and they could grow to over 50 feet in length, about the size of modern sperm whales. , reports Vishwam Sankaran for the Independent.

“Since the first discoveries of skeletons in southern England and Germany more than 250 years ago, these ‘fish-saurians’ have been among the first large fossil reptiles known to science, long before the dinosaurs, and they’ve captured the popular imagination ever since,” study author Martin Sander, a paleontologist at the University of Bonn and researcher at the Los Angeles County Museum of Natural History (NHM), says in a Press release.

In 2011, scientists discovered an eight-foot-long ichthyosaur skull in the mountains of Nevada. The creature had a long dolphin snout and conical teeth. It was searched with part of the animal’s spine, fin and shoulder, reports Alexandra Larkin for SCS.

The fossil belongs to a new species named Cymbospondylus youngorum it is estimated to have lived around 246 million years ago, making it the largest fossil from that time ever discovered.

A researcher lies down next to the skull.  The scientist's head is near the end of the snout, and his legs reach part of the jaw, about two feet shorter than the end of the skull.

The skull belonged to a creature from 246 million years ago and is the largest fossil from that time ever found.

Martin Sander, courtesy of Los Angeles County Museum of Natural History

The specimen offers new insights into what the ocean was like millions of years ago and how ichthyosaurs got so big. The scientists reported their findings last month in the journal Science.

Although ichthyosaurs and whales never existed at the same time, they have more in common than their similar body size and shape. They both evolved from land-walking ancestors, and their gigantic bodies made them the largest ocean animals of their time.

Over the vast evolutionary timeline, ichthyosaurs developed their enormity with lightning speed, reports Sabrina Imbler for the New York Times. After their ancestors moved from land to sea, it took only three million years for ichthyosaurs to evolve their gigantic body size. In comparison, it took 45 million years for whales to reach such enormity, the Time reports.

To understand how ichthyosaurs grew so quickly, the team of scientists pieced together their food web at the time. About 252 million years ago, the Permian extinction wiped out about 96% of ocean species, but it left the door open for creatures like ammonites – a type of mollusk – and creatures resembling to eels called conodonts flourish, according to the press release.

Many of the largest modern whales, like humpbacks and blue whales, feed on tiny organisms like plankton, which has helped them grow to such large sizes. But a similar food web was not possible for ichthyosaurs. Plankton were not around in their day and ammonites instead formed the basis of food webs. Reptiles did not feed directly on shellfish, but they ate the critters that ate them, such as fish and squid, Time reports.

Although scientists aren’t sure exactly how ichthyosaurs grew so fast, one reason could be that the boom in ammonites and conodonts filled a gap in the food chain that reptiles could exploit, according to the press release.

“As researchers, we often talk about similarities between ichthyosaurs and [whales and dolphins]but rarely delve into the details,” NHM curator Jorge Velez-Juarbe says in the press release. additional information on changes in body size. within these groups.

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