The Tidbits on Hand

A great deal of paleontology is often done, and we have seen this many times over, with fragmentary evidence. Sometimes, as we have seen, little more than a few phalanges are discovered in any one dig and, sometimes, these very few bones are used to identify an entire animal. That is by no means impossible, but some remains' identifications seem quite improbable. Luckily for Staurikosaurus its initial skeletal remains were enough to justify a new species even though they were still fragmentary enough to still have detractors. Both sides of the arguments would make sense if we step back and look at the evidence from each viewpoint. On the one hand we have a fairly clearly early theropod dinosaur that has very few derived characters but enough to justify its classification as a primitive dinosaur rather than just another archosaur. The opposite view, while not popular or even represented to my knowledge at present, would hold that Staurikosaurus is simply an archosaur that lived alongside dinosaurs or just prior to the earliest dinosaurs. The defining line between archosaur and dinosaur sometimes gets fuzzy (depending on the source of the definition), so any confusion of the placement of Staurikosaurus is probably due to this grey area. Just for our purposes, we can treat archosauria as a crown group that contains only extant animals such as crocodiles and birds. Thus Staurikosaurus being considered a dinosaur means that it is not a bird or a crocodile, in the simplest of terms; one can see where the confusion occurs. Regardless, Staurikosaurus possesses some very nice basal dinosaur traits such as its minimal sacral vertebrae (only 2 exist) and elongated cervical vertebrae. Despite being as basal as Staurikosaurus is, it is thought to have evolved in the theropod line after sauropods had already begun to evolve differently in the saurischian branch. Staurikosaurus and its sister taxa (Herrerasaurus chiefly) certainly warrant more investigation than I have given here this week. Hopefully very soon even more material will be discovered (in Argentina or Brazil) and more studies can be conducted. Not really my cup of tea as far as an academic project is concerned though, so it probably will not be my thesis work!