In addition to the mounted skeleton shown yesterday, as usual the Carnegie provided a little extra something. In this case it’s a nearly complete skull of a young Dryosaurus (the label lies in the orbit and it’s facing to the left).
I must confess to knowing little about this ornithischian (also true of many ornithischians I admit) though it helps illustrate one small point. Not that long ago, it was thought that sometime in the Middle to Late Jurassic there was a landbridge from Africa to North America. This was invoked to explain the apparent incredible similarity between the Tendaguru and Morrison faunas. Both had Dryosaurus, and Allosaurus and Brachiosaurus, and both had stegosaurs and diplodocids.
However, better examination of the available material makes the Tendaguru brachiosaur not Brachiosaurus, the allosaur not Allosaurus and the small ornithopod is Dysolotosaurus and not Dryosaurus. In short, there’s no need to invoke a special land-bridge since the two faunas are not identical. Similar sure, with each having representatives of the same families, but that’s hardly surprising – look to the modern world and the two continents feature felids, canids, mustelids, bovids and others and such comparable faunas are quite normal.