Jurassic Giants: The Old, The New, and the Obscure

The most famous sauropods -- Apatosaurus, Diplodocus, Camarasaurus, Brachiosaurus, and now Brontosaurus again -- all hail from the Morrison Formation of the western United States, extending from Montana to New Mexico and the end of the Jurassic (roughly 155 to 145 million B.C.E.). These were hardly the first sauropods to evolve or be named, and while some genera from the Cretaceous (like Argentinosaurus and Dreadnoughtus) were even larger, the Late Jurassic is generally regarded as these dinosaurs' heyday, celebrated in documentaries like Walking with Dinosaurs and When Dinosaurs Roamed America.

Some Early Jurassic sauropods, though, do deserve a mention: Barapasaurus, from the Kota Formation in southeastern India, is one of the earliest definitive large sauropods, dating back to between 195 to 180 million B.C.E. It measured about 40 to 45 feet long and around 8 tons -- about the same length and weight as T. rex, and making it one of the largest animals ever to walk the Earth at the point in time. More importantly, however, are its front toes, which retain the large claws of the sauropods' bipedal antecedents, the plateosaurs (or prosauropods), hinting its primitive place. While most of the skeleton has been found, a Barapasaurus head is still unknown. The drawing below is based on a mount at the Indian Statistical Institute in Kolkata, whose staff gave it a very Diplodocus-like head.

Cetiosaurus, the first sauropod ever described, roamed modern England around 165 million B.C.E. On the face of it, it's a rather un-glamorous, undistinguished sauropod, being only about 50 feet long and around 12 tons, though its toes claws are much blunter than Barapasaurus'. Here too, the restored skull is speculative, displaying cranial chambers that characterize Camarasaurus as well as the pencil-like teeth of Apatosaurus and Diplodocus. This drawing is based on the "Rutland sauropod" specimen on display at the New Walk Museum, located in Leicester in central England.

Even some of the Morrison sauropods aren't classic dinosaurs. In 2012, paleontologists Emanuel Tschopp and Octávio Mateus described Kaatedocus, a new diplodocoid from lower (i.e. older) Morrison Formation beds in Wyoming. Earlier this year, same two paleontologists, along with Roger Benson, described Galeamopus, a rechristened former species of Diplodocus.

As with previous sauropod drawings, I've elected to make the sauropod necks the most colorful and intricately-patterned part of the animal for display and identity purposes. For Galeamopus, I actually adapted the calico cat's light orange and inky black fur, only as scales.