Jurassic Fossil Of Extinct Baby Reptile Has Squid Tentacles In Stomach

Scientists studying the fossil of a newborn reptile from 200 million years ago know what the baby ate for dinner right before it died: squid.

Where the ichthyosaur’s stomach used to be, there were lots of hooks left behind from squid tentacles, which the cephalopods use to grab onto food themselves. The marine animal that ate the squid is the smallest and youngest of its kind ever found, the University of Manchester reported, and has evidence of a different diet from what researchers have previously found.

“It is amazing to think we know what a creature that is nearly 200 million years old ate for its last meal,” paleontologist and ichthyosaur expert Dean Lomax said in the statement. “We found many tiny hook-like structures preserved between the ribs. These are from the arms of prehistoric squid. So, we know this animal’s last meal before it died was squid.”

The newborn ichthyosaur, Ichthyosaurus communis, lived shortly after the time that the Triassic geological period ended and the Jurassic began. Other young fossil specimens from a related species, within the Ichthyosaurus genus, have been found to eat only fish, so the finding that this communis newborn ate squid sets it apart from the others, which lived more recently in Earth’s history.

It was a little more than 2-feet long, which the scientists refer to as “very small” in their study in the journal Historical Biology.

Previously scientists have found pregnant adult fossils from this group and studied the embryos. For comparison, the embryo of an Ichthyosaurus somersetensis that was recently studied was only about 2.5 inches long.

But the relatively tiny creature that is the focus of the new study had already been born.

“It is not an embryo as it is not preserved within an adult specimen and stomach contents are clearly evident,” the authors wrote. “This is therefore the first neonate Ichthyosaurus communis skeleton to be described.”

The communis species was first discovered in the early 1800s, and the first of the marine reptile ichthyosaurs found. They are common fossils in the United Kingdom, although they could be found around the prehistoric world. The ichthyosaurs evolved before the first dinosaurs and, while they looked a bit like porpoises, are closer relatives of modern lizards and snakes.

“There are several small Ichthyosaurus specimens known, but most are incomplete or poorly preserved,” Lomax said. “This specimen is practically complete and is exceptional. It is the first newborn Ichthyosaurus communis to be found, which is surprising considering that the species was first described almost 200 years ago.”

It was being housed at a museum without a record of where and when it was found. But the scientists were able to date the fossil itself, finding that it was between 196 million and 199 million years old.

They did that work by analyzing the other tiny fossils that were also preserved in the rock with the ichthyosaur.

“Many historic ichthyosaur specimens in museums lack any geographic or geological details and are therefore undated,” paleontologist Nigel Larkin, from the University of Cambridge, said in the statement. “This process of looking for microfossils in their host rock might be the key to unlocking the mystery of many specimens.”