A new species of Velociraptor

The type skull of Velociraptor mongoliensis. From Osborn, et al. 1924.

By the summer of 1993 Velociraptor had become a household name. Although Deinonychus had long been my fleet-footed favorite the olive-green “clever girls” of Speilberg’s film soon outshone all of their relatives and gave Tyrannosaurus a run for it’s money.* Velocriaptor is hardly a new dinosaur, however. It was discovered during the famous expeditions to Mongolia made by the AMNH in the 1920’s, the team setting out to find the “birthplace” of all mammals and coming back with loads of new dinosaurs. Velociraptor mongoliensis was officially described, along with Saurornithoides and Oviraptor, in 1924 but was practically invisible to the public until it starred in the movie that would make the “raptor” famous.

Now there’s a new kid in town, a new species of the sickle-clawed predator called Velociraptor osmolskae from Bayan Mandahu in Mongolia. The locality, with deposits between approximately 83 and 70 million years old, presents an array of horned and armored dinosaurs with theropods being relatively rare. Fossils attributed to Velociraptor had been found there in the past but have generally been forgotten, but a pair of jaw bones (the maxillae) discovered in 1999 represented something new. It definitely represented some kind of dromeosaurid, but what kind was it? A few landmarks on the preserved maxillae contained some crucial clues.

Like Velociraptor mongoliensis the specimens had a single row of holes, called neurovascular foramina which contained blood vessels and nerves in life, lining the lateral surface. Furthermore, an opening in the skull called the maxillary fenestra (the large, tear-drop shaped hole on the right in the illustration below) was consistent with that of Velociraptor, the number of teeth in the maxillae also being very similar. There are important differences, however, primarily the absence of a ridge near the neurovascular foramina seen in V. mongoliensis and slight differences in the tooth structure. A comparative chart included in the paper makes it clear; the new specimens are most similar to V. mongoliensis while still presenting some new features. As the researchers themselves note more material is required to lock in this hypothesis but there seems to be enough distinct charcteristics to justify Velociraptor osmolskae.

The left maxilla of Velociraptor osmolskae. From Godefroit, et al. 2008.

The new species also brings up an interesting question of speciation in the fossil record. The area in which V. osmolskae was found is not far from other highly productive fossil sites from about the same time containing very similar groups of animals. Although it cannot be absolutely proven it is possible that there are several deposits from the same time containing nearly the same animals. The faunas from the Bayan Mandahu and Djadokhta formations are similar but are slight differences between them; could V. osmolskae have been derived from a group of Velociraptor isolated from others by a harsh desert or other barrier? Lizards seem to overturn this view, the presence of the same lizards at localities of about the same age from both formations making the idea of an impassable geographic barrier untenable. The most that can be said is that there were regional differences between the faunas of this area, perhaps due to slight age differences or geography.

Velociraptor osmolskae is significant for another reason. It is named after the Polish paleontologist Halszka Osmolska, who passed away this past March. She was one of the members of the Polish-Mongolian teams that explored the deposits of Mongolia from 1965-1970, describing such genera as Homalocephale, Bagaceratops, and Gallimimus. While the AMNH expeditions are often the most publicized and celebrated the work undertaken during the 1960’s and 1970’s during the Polish-Mongolian expeditions added much to our understanding of paleontology and it is good to see Osmolska receiving posthumous recognition for her efforts.

[*As I have mentioned here before the dromeosaurs in the film really were Deinonychus, albeit by a different name. It can all be attributed to a game of pop-science telephone. Michael Crichton read Gregory Paul’s Predatory Dinosaurs of the World in which Paul said Deinonychus should be lumped into Velociraptor, Crichton carrying on this taxonomic reshuffling into his novel which was then translated to film. For whatever reason Jack Horner maintained this change (which has been rightly rejected) in interviews about the Jurassic Park films, saying as late as the third installment that only recently had good skulls of Velociraptor become known despite a wonderfully preserved one being used to describe the genus in 1924. All of this led to even more confusion in the media, paleontologists recognizing that the Velociraptor on film being far too large and the media jumping on the discovery of Utahraptor as a confirmation of the portrayal of big dromeosaurs in the film. What a tangled web we weave…]

References;
Godefroit, P., Currie, P.J., Hong, L., Yong, S.C., Zhi-Ming, D. (2008). A New Species Of Velociraptor (Dinosauria: Dromaeosauridae) From the Upper Cretaceous Of Northern China. Journal of Vertebrate Paleontology, 28(2), 432. DOI: 10.1671/0272-4634(2008)28[432:ANSOVD]2.0.CO;2
Osborn, H.F.; Kaisen, P.C.; Olsen, G. (1924) “Three new Theropoda, Protoceratops zone, central Mongolia.” American Museum Novitates, no. 144, pp. 1-12