Deinosuchus is a large alligatoroid from the Late Cretaceous period of North America. It is in the same superfamily, but not an ancestor, of today’s alligators. Its body length is thought to have been up to 12 metres. The remains are incomplete, which makes it hard to accurately measure its length, but it’s possible to compare the bones with those of smaller alligator skeletons to get a rough size. Its maximum weight was said, in the journal Nature in 1999, to be between three and five times the weight of today’s largest crocodilians.