Way cool ancient, gigantic crocodile

This counts as a unicorn chaser, of sorts, for that depressing space travel post of mine.

That big mandible in the picture above belongs to Acherontisuchus guajiraensis, a recently identified species of ancient crocodile, living in what is now Colombia. A. guajiraensis would have been 20 feet long.

Most of the articles out on this find are focusing on the fact that the giant crocodile shared a habitat, and would have competed for food, with Titanoboa—a giant snake that could grow up to 50 feet long. Please make a note: If you invent a time machine, I would like to travel with you. But not to Paleocene South America, OK?

But anthropologist Greg Laden points out something else that's pretty cool about this crocodile: It has some implications for the way we think about evolution.

The most significant part of this find with respect to evolutionary theory is this: When we see a diversity of animals living at the same time, and one form (living or reconstructed) seems to be the basal, primitive, less specialized one, it is easy to assume that this is most like the ancestor to all the other forms. In other words, a generalized form gives rise to many different species, some or many of which are specialize. However, the reconstruction of dyrosaurid evolution prompted by this find suggests that a diversity of specialized forms could arise from a prior also-specialized form. This, of course, could relate to the fact that the dyrosaurids diversified after the K-T boundary extinction event, probably in a world with many empty niches previous occupied by other crocodiles that were wiped out during that event.