When is a dinosaur not a dinosaur?

When it’s a phytosaur or a rauisuchid, that’s when.

In Virginia Tech News today is a story about two important predators who preyed on each other about 210 million years ago. Since one species lived on land and the other lived in the sea, it was thought there was little interaction between the two.

College of Science paleontologists changed that thinking when they came across an unassuming bone in a museum. When they analyzed it, they found a phytosaur tooth lodged in a bone from a rauisuchid. The twain did meet (in the thigh bone, to be specific), despite longstanding ideas about there being no contact between the predators.

Probably the much bigger (more than 25 feet) rauisuchid waded where it shouldn’t have.

For those of you crying for some sort of point, it is this: It is natural to think these animals were dinosaurs, but they actually preceded the dinosaurs.
But when these critters were cruising the creeks, their younger cousins, the dinosaurs, were just getting a start in the world.

Phytosaurs resemble today’s crocodiles and alligators, although the first paleontologists thought they were plant eaters and gave them a name that literally means “plant reptile.” Later, when fossil hunters found teeth, it became obvious these animals weren’t using them to munch on salad.

Now, we know leg of rauisuchid was on the menu.