FossiLab has been overrun by crocs. Since November, National Museum of Natural History visitors have been watching us create archival storage for the Department of Paleobiology's extensive collection of fossil crocodilians. Ranging from individual teeth to nearly complete skeletons and in age from about 66 million to just a few million years old, the hundreds of fossils in this collection are the fruit of more than 150 years of collecting by Smithsonian staff and their professional and amateur colleagues.
Like most people, we are impressed by fossils with big teeth, but the collection contains less toothy marvels as well. Here are some highlights from our work:
This 10 million year old specimen of Gavialosuchus (USNM 24939) was found nearby in Maryland. The jaws and other skull fragments are shown resting in newly-created archival storage trays.
Sorting through drawers holding a specimen of Boverisuchus vorax (USNM 12957) collected by Charles W. Gilmore in Wyoming in 1930, we found the fragmented and incomplete skull, shown in the foreground of the photo above, left. FossiLab volunteer David Ouderkirk, right, was able to piece many of the skull fragments back together before rehousing it. Boverisuchus (formerly known as Pristichampsus) is noteworthy for its teeth, which are similar to those of predatory dinosaurs. It may have primarily been a land-dwelling predator.
One of the most historically interesting of the storage drawers contained nearly a hundred small boxes of fossils recovered by collectors for the famous 19th century paleontologist O.C. Marsh at a site called Quarry 9 at Como Bluff in Wyoming. This quarry is famous for yielding thousands of fossils of small vertebrates from the Morrison Formation (Late Jurassic), among them mammals, small dinosaurs, amphibians - and crocodilians. The pair of photos above shows the drawer before, left, and after, right, the fossils and their historic labels were cleaned and rehoused.
The crystals that fill this lovely specimen, USNM 12597, makes it appear geode-like, but microscopic analysis of the outer layer reveals structures typical of crocodilian eggshells. The egg was laid during the Eocene, about 45 million years ago, and is one of several collected in present day Wyoming in 1930.
The collection also contains some casts (exact replicas) of croc specimens, and we are improving storage for these as well. But sometimes we have a little fun with them first. The cast above is of the specimen of Gavialosuchus shown in the first photo of this post. Yes, we really are impressed by fossils with big teeth!
This work is part of a long-running effort in the Department of Paleobiology to update storage for all of our fossils. Next up for rehousing in FossiLab is the fossil marine mammal collection.