Lesotho is a remote, mountainous region in southern Africa, where fossilized remains of this dinosaur were first discovered in 1978. Lesothosaurus remains have also been found in South America, which was connected to Africa's west coast at the time. Because of its hot, dry conditions in an area relatively unmolested by man, Lesotho has been a valuable source for dinosaur hunters.
Lesothosaurus is very similar to the previously discovered fabrosaurus. In fact many scientists believe the two were actually the same animal. Remains of fabrosaurus, however, are so poor that it is impossible to say for sure.
Lesothosaurus had hollow bones and a small, light skeleton. Its only defense against a large predator would have been its ability to run away quickly, similar to the behavior of modern gazelles.
This animal shares many features with other ornithischian dinosaurs in addition to the bird-like hipbones. A "predentary" bone links the left and right sides of the lower jaw together. This bone was covered with a horny sheath, giving the animal a beak shaped mouth without the fleshy cheeks of most meat eaters. It also had a bone across its eye and eye socket, similar to those found in modern crocodiles.
It is interesting to note that, although it lived 208-200 milliuon years ago, ages before the first mammals, lesothosaurus had five digits on each hand and five toes on each foot.
For a long time, lesothosaurus was considered a very early ornithischian, related to hadrosaurs (duck-billed dinosaurs) and hypsilophodon. These animals were seperated from each other by more than 80 million years, however, leading one to believe that lesothosaurus actually has no close relative known to modern science. For this reason, it is difficult to classify on the dinosaur family tree.
Was lesothosaurus the mother of all carnivorous dinosaurs, or is the resemblance simply a coincidence?
For my previous posts on dinosaurs, click here.