The new Journal of Vertebrate Paleontology can't come out fast enough

One of the most difficult things about writing about fossil whales is that so few of them have been figured in books and papers. There are a few skeletal reconstructions that are reproduced over and over and over again, but in my research some genera are only mentioned by name. Georgiacetus is one such example.

Georgiacetus is one of those neat archaeocetes that exemplifies the transition from land to water among the earliest whales. It was not fully aquatically adapted like Basilosaurus and Dorudon, but at the same time it was proportioned very differently from earlier creatures like Pakicetus and Ichthyolestes. Indeed, while the skull of Georgiacetus was very long and somewhat resembled that of the more aquatically-adapted forms, in general it looked more like its close relative Rodhocetus.

How can I say this? Well, by chance I happened to notice that the Society of Vertebrate Paleontology just issued a press release about a new paper based upon more complete Georgiacetus material that has given us a better look at the animal. Where I had previously envisioned it as being a little more streamlined with stubbier limbs, the reconstruction accompanying the press release presents an animal with a streamlined body but still retained prominent limbs with expanded digits used for paddling.

The species being discussed in the article is Georgiacetus vogtlensis, both the genus and species being described in 1998 (paper here; if someone has access could they please send me a copy? I have now received a copy. Thank you!). The fossils were discovered as a result of excavations for the Vogtl nuclear power plant in the state of Georgia in the U.S. during the 1980's. You can have a look at the specimen yourself here, and it is quite different from how I initially envisioned it. (Indeed, some reconstructions of Protocetus colored my view in the absence of any reconstructions of Georgiacetus.)

In any event, the paper should be interesting as new skeletal material has provided more information about the evolution of whale locomotion. I'll wait to read it before jumping in to such a discussion, but I'll be anxiously awaiting the moment the new paper becomes available.

[As something of an afterthought, it is worth noting that archaeocetes spread to what is now North America before their hind limbs became reduced to the degree seen in Basilosaurus isis from Egypt. While much of early whale evolution occurred in what is now Pakistan, it appears that Rodhocetus-grade archaeocetes made it across the Atlantic before their hind limbs became especially reduced. This is very interesting, suggesting that vertical undulation of the spine (and using the limbs to steer, as the hips of Georgiacetus were separated from the spinal column) was a mode of swimming effective enough to allow for the crossing of oceans before derived caudal flukes evolved!]