Walking Around

Two legs or four?Larger, later, thyreophorans are always illustrated as walking on four legs because of their immense size. There are temporary exceptions to this rule, however, as Stegosaurus is often portrayed rearing up up on two legs to get at the leaves on tall fern trees that it appears to have difficulty getting to otherwise. This is not walking, of course, but should be noted as an exception all the same. The basal member Scutellosaurus, like many basal taxa, appears to have had the ability to walk bipedally and could have been facultatively quadrupedal. This is something we commonly see in basal taxa of dinosaur families that eventually reach enormous sizes. There are many reasons that this kind of morphological occurs. Most often, as in this case, it is partly because of the small size of the basal members of the eventually enormous taxa. Scutellosaurus started off as one of those extremely small taxa and this may explain entirely why it appears to have been mostly bipedal. This could also be an artifact of the known skeletal elements.

©Jaime A. Headden