In the Middle-Jurassic on Scotland’s Isle of Skye, “dwarf crocodiles” lived among dinosaurs. At this point in time, Skye was a tropical island with rivers, lagoons, and lakes. These provided a more than suitable environment for the semiaquatic Theriosuchus. They also supported a huge diversity of life.
At one foot long, Theriosuchus was a small animal. This was likely due to niche specialization, where a single species evolves to carry out a very specific role in an ecosystem. Specializing in such a way can reduce competition with other animals of similar lifestyles. Alternatively, its small size could have been the result of living on an island isolated from other crocodilian populations. This would have caused Theriosuchus to diverge off of the typical crocodilian evolutionary path.
Although the discovered fossil was merely a fragment of a jaw, researcher Mark Young and his team were able to figure out the the animal’s identity. Theriosuchus is considered to be a member of the group Neosuchia, which includes all living crocodilians as well as their closest fossil relatives.