Size and Weight:
You'd have to be in the know to get the joke, but the person who named Antetonitrus ("before the thunder") was making a coy reference to Brontosaurus ("thunder lizard"), which has since been renamed Apatosaurus. As a matter of fact, this Triassic plant-eater was once thought to be a specimen of Euskelosaurus, until paleontologists took a closer look at the bones and realized they might be looking at the first-ever true sauropod. In fact, Antetonitrus seems to have possessed anatomical characteristics reminiscent of both prosauropods ("before the sauropods"), such as movable toes, and sauropods, such as relatively small feet and long, straight thigh bones. Like its sauropod descendants, this dinosaur was almost certainly limited to a quadrupedal posture.