Fossil with Crocodile and Cat Traits

Pakasuchus kapilimai is classified as a crocodile, but if it lived today it probably wouldn’t frighten anyone: its entire head would fit in the palm of your hand. Fossils of the creature were discovered in Tanzania and are described in the journal Nature.

Pakasuchus’s teeth look not like a modern crocodile’s, but instead like a cat’s.

“At first glance, this croc is trying very hard to be a mammal,” joked Patrick O’Connor, the Ohio University anatomist who led the research team. “If you only looked at the teeth, you wouldn’t think this was a crocodile. You would wonder what kind of strange mammal or mammal-like reptile it is.”

That’s because Pakasuchus’s teeth look not like a modern crocodile’s, but instead like a cat’s—more mammalian than reptilian. Specifically, the creature had teeth with shearing edges, a feature previously thought to exist only in mammals. For this and other reasons, the team believes the crocodile would have chewed and swallowed just like a mammal.

According to O’Connor’s team, that fact, along with the animal’s “extremely flexible” backbone, shows that crocodiles were more diverse millions of years ago than they are today. For creationists, the fossils serve to remind that genetic information decreases over time—both in populations and in particular species. Although the diversity of genes expressed may increase (as is the case with dogs; see item ), we often observe the opposite, which is why the fossil record houses many fascinating creatures different from those living today.