Aardonyx (Greek for "earth claw"); pronounced ARD-oh-nix
Woodlands of southern Africa
Early Jurassic (195 million years ago)
Size and Weight:
About 20 feet long and 1,000 pounds
Long neck and tail; long, low-slung body
Only "diagnosed" in 2009 based on two juvenile skeletons, Aardonyx was an early example of a prosauropod--the plant-eating precursors of the huge sauropods of the late Jurassic period. What makes Aardonyx important from an evolutionary perspective is that it seemed to pursue a mostly bipedal lifestyle, dropping occasionally to all fours to feed (or perhaps mate). As such, it captures an "intermediate" stage between the lighter, bipedal herbivorous dinosaurs of the early and middle Jurassic periods and the heavier, quadrupedal plant eaters that evolved later.