55-foot-long Triassic sea monster discovered in Nevada

Another sea-dweller during the prehistoric age was discovered, a new species called Cymbospondylus youngorum- this one in Nevada (which was underwater of course, millions of years ago). A bus is usually between 35 and 45 feet long, and this ichthyosaurs (with very sharp teeth) is longer than that! >

The size of the new ichthyosaur is perhaps best illustrated with a human for scale. (Image credit: Photo by Martin Sander)

55-foot-long Triassic sea monster discovered in Nevada 

By Laura Geggel , LIVESCIENCE

 The beast shows that ichthyosaurs grew big really fast.

A sea monster that lived during the early dinosaur age is so unexpectedly colossal, it reveals that its kind grew to gigantic sizes extremely quickly, evolutionarily speaking at least.

The discovery suggests that such ichthyosaurs — a group of fish-shaped marine reptiles that inhabited the dinosaur-era seas — grew to enormous sizes in a span of only 2.5 million years, the new study finds. To put that in context, it took whales about 90% of their 55 million-year history to reach the huge sizes that ichthyosaurs evolved to in the first 1% of their 150 million-year history, the researchers said.

"We have discovered that ichthyosaurs evolved gigantism much faster than whales, in a time where the world was recovering from devastating extinction [at the end of the Permian period]," study senior researcher Lars Schmitz, an associate professor of biology at Scripps College in Claremont, California, told Live Science in an email. "It is a nice glimmer of hope and a sign of the resilience of life — if environmental conditions are right, evolution can happen very fast, and life can bounce back."

Researchers first noticed the ancient ichthyosaur's fossils in 1998, embedded in the rocks of the Augusta Mountains of northwestern Nevada. "Only a few vertebrae were sticking out of the rock, but it was clear the animal was large," Schmitz said. But it wasn't until 2015, with the help of a helicopter, that they were able to fully excavate the individual — whose surviving fossils include a skull, shoulder and flipper-like appendage — and airlift it to the Natural History Museum of Los Angeles County, where it was prepared and analyzed.

Caption: An illustration of Cymbospondylus youngorum in a Triassic ocean teeming with life. Ammonites and squid were abundant in this open ocean environment.  Image credit: Illustration by Stephanie Abramowicz, courtesy of the Natural History Museum of Los Angeles County (NHM).)

The team named the new species Cymbospondylus youngorum, they reported online Thursday (Dec. 23) in the journal Science. This big-jawed marine reptile lived 247 million years ago during the Triassic period. Like other creatures from that time, it was weird. "Imagine a sea-dragon-like animal: streamlined body, quite long, with limbs modified to fins, and a long tail," Schmitz said. With a nearly 6.5-foot-long (2 meters) skull, this full-grown C. youngorum would have measured over 55 feet (17 m), or longer than a semitrailer, the researchers found.

When the 45-ton (41 metric tons) C. youngorum was alive, C. youngorum would have lived in the Panthalassic Ocean, a so-called superocean, off the west coast of North America, Schmitz said. Based on its size and tooth shape, C. youngorum likely ate smaller ichthyosaurs, fish and possibly squid, he added.

WHAT MAKES THIS MORE IMPRESSIVE -

There are many huge beasts that lived during the dinosaur era, but C. youngorum stands out for several reasons. For instance, C. youngorum lived just 5 million years after "the Great Dying," a mass extinction event that occurred 252 million years ago at the end of the Permian period, which killed about 90% of the world's species. That makes the ichthyosaur's huge size all the more impressive, as it took about 9 million years for life on Earth to recover from that extinction, a 2012 study in the journal Nature Geoscience found.