Hello everyone. Here are some simple sketches of three Late Jurassic sauropod dinosaurs from the Morrison Formation of western North America: Apatosaurus, Barosaurus, and Diplodocus. All three of these sauropods are members of the family Diplodocidae, which includes the eponymous Diplodocus and any other sauropod that’s more closely related to Diplodocus than to any other sauropod group. The “diplodocids”, as these species are sometimes called, are distinctive for having long peg-like teeth in the fronts of their jaws (good for raking and stripping, but not well-suited for biting), a nares (the hole in the skull that contains your nostril openings) that’s located on the top of the skull, and long tapering whip-like tails.
The first is Apatosaurus louisae, which measured around 75 feet long. Like all diplodocid sauropods, Apatosaurus had a long whip-like tail, but it also had a massive thickly-built neck. Some paleontologists hypothesize that Apatosaurus used its neck in whacking contests during the mating season like modern-day giraffes. You can read more about that here.
Apatosaurus louisae. © Jason R. Abdale. May 11, 2020.
Next is Barosaurus lentus, which measured around 85 feet long. This animal was made famous by the impressive display in the entrance hall of the American Museum of Natural History in New York City. Notice that the neck and the tail are almost the same size; the tail is only slightly longer.
Barosaurus lentus. © Jason R. Abdale. May 11, 2020.
Finally is Diplodocus carnegii, which measured around 90 feet long. For a long time, this animal held the record as the longest dinosaur ever, until it was challenged by Supersaurus, Seismosaurus (which is almost certainly another species of Diplodocus), and various titanosaurid sauropods from South America. Of all of the diplodocid sauropods, Diplodocus itself had the longest tail. Some have speculated that the long ribbon-like tails of Diplodocus and its kind were used like whips, and it was even calculated that they could be cracked like a modern-day bull-whip. In the early 1990s, a partial skeleton of a Diplodocus-like dinosaur was found in Howe Quarry, Wyoming which had preserved skin impressions, including a series of keratin spikes similar to those seen on the back of an iguana lizard. An article was published about this discovery in 1992, which you can read here, although it wasn’t expressly stated within the report that the creature in question was indeed a Diplodocus. However, many paleo-artists ran with the idea anyway, and it was even incorporated into the 1999 BBC television series Walking With Dinosaurs. Since this is the prevailing trend, I decided to outfit my Diplodocus razorback-style as well.
Diplodocus carnegii. © Jason R. Abdale. May 11, 2020.
Next is an image showing a size comparison between Apatosaurus (75 feet), Barosaurus (85 feet), and Diplodocus (90 feet). For some people, it can be difficult to mentally grasp the size and the anatomical differences of these animals just by looking at numbers on a page. Perhaps by looking at this picture, you can truly appreciate the differences in the size proportions. Apatosaurus is a muscular beast. Barosaurus looks like a see-saw with legs. Diplodocus‘ tail measures three-fifths of its whole body length. So, as you can see, not all sauropods are the same.
A size comparison between Apatosaurus (75 feet), Barosaurus (85 feet), and Diplodocus (90 feet). © Jason R. Abdale. May 11, 2020.
Keep your pencils sharp, everyone.