Don’t bite any more than you can chew, the saying goes. But an ancient ichthyosaur did that.
The 5-meter-long marine reptile has the body of a 4-meter-long animal in its abdomen, but damages the neck while eating the big meal and died a short time later. The dam is the largest discovered in the abdomen region of a fossil.
Dolphin-like ichthyosaurs thrived about 250 to 90 million years ago. The appearance of their teeth suggests that some of the giantr specimens were prominent predators that fed on giant prey, however, there is little direct evidence of what they ate.
In 2010, a team that added Motani discovered a giant ichthyosaur fossil in a quarry in southwest China, known as belonging to the genus Guizhouichthyosaurus. It took two years to remove the fossil and prepare it, revealing a surprise.
“There’s something in his abdomen that sticks out, ” said Motani.
Researchers continued to search for the site, which has become a museum, as they tried to identify the dam. Seven years later, they have yet published their findings.
The ichthyosaur, which lived in the Middle Triassic, faced another marine reptile called thalattosaur. This lizard-shaped animal is almost as long as ichythysaurium, but much thinner, Motani said. Its mass is probably only one sixth or one-eighth of that of ichthyosaur.
At the time of discovery, this thalattosaur was an unknown species. Since then, some other individuals have been discovered at the same site and the species called Xinpusaurus xingyiensis.
The ichthyosaur bit the head and tail of the talattosaur, shaking it. Then he swallowed the body decapitated and without a tail. “It’s a great piece,” Motani says.
But at some point, maybe the initial attack, the ichthyosaur injured his neck. This injury could possibly have bothered by shaking and swallowing the talattosaur.
“The neck was damaged to the point that he could no longer hold his skull,” Motani explains. “I couldn’t breathe.”
The explanation of why the team thinks this is the maximum likely situation is that, the head of the ichthyosaur separated slightly from the rest of the frame where the neck was injured, the rest of the frame is intact. There is no explanation why to believe, for example, that some other predator attacked the ichthyosaur.
The body of the talattosaur has no symptoms of degradation by digestive juices and its bite tail is discovered just 23 meters in the same layer of rock. This suggests that the ichthyosaur died almost without delay after swallowing it.
The talattosaur may have been unusually large, Motani said. The other individual and similar species of X. xingyiensis are smaller and measure only 1 to 2 meters long. Maybe the ichthyosaur didn’t realize how wonderful its prey was.
There are examples of badly judged predators through their prey, such as the dolphin suffocated by the giant octopus he tried to eat.
It is incredibly uncommon for fossils to give us such a detailed view of the life and death of animals. Only a few examples are known.