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“Our ichthyosaur’s stomach contents weren’t etched by stomach acid, so it must have died quite soon after ingesting this food item”

Ancient marine reptile was a big eater

A 240-million-year-old fossil has revealed that dolphin-like ichthyosaurs could gobble up animals almost as big as themselves. It's the first direct evidence of 'megapredation' — one large animal eating another — in the ancient world. Ichthyosaurs were marine reptiles that lived during the time of the dinosaurs. 'The fossilised ichthyosaur in this new study was uncovered in a quarry in southwestern China. It's an almost complete skeleton, around five metres long, with the bones of another marine reptile called a thalattosaur preserved inside its stomach. The thalattosaur was around four metres long and more lizard-like than the ichthyosaur, with four paddling limbs. The bones found inside the ichthyosaur's stomach correspond to the thalattosaur's middle section, from its front to back limbs. "Our ichthyosaur's stomach contents weren't etched by stomach acid. so it must have died quite soon after ingesting this food item," said study co-author Dr Ryosuke Motani, a palaeobiologist at the University of California, Davis. The researchers don't know for sure whether the ichthyosaur killed the animal itself. or whether it was scavenging another predator's kill. But several pieces of evidence suggest that it was a direct kill, including the fact that the nutritious torso and legs were still intact — this probably wouldn't have been the case if another predator had got there first. The ichthyosaur had relatively small, peg-like teeth, suggesting that, rather than neatly slicing through its victim, it would have gripped it before ripping or tearing it apart. Predators such as orcas, leopard seals and crocodiles use a similar technique. "Now, we can say for sure that [ichthyosaurs] did eat large animals," said Motani. "This also suggests that megapredation was probably more common than we previously thought."