Laelaps

A new species of Velociraptor

i-18afb9c023abd67890be4aa543a5fdd2-velociraptorskull.JPG

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

ResearchBlogging.org 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.

i-1e6bd848372e2c02bdf228227a39eb25-newvelocimax.JPG

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

Comments

  1. #1 Hai~Ren
    July 14, 2008

    But what if the lizards are actually different species, and could have only been told apart by differences in coloration or habitat preference? ;-)

    Ah yes, distinguishing species in paleontology is such a muddled mess. But I don’t think it is necessary to have species separated by time or unpassable barriers. They could after all be closely related but still be sympatric.

    The example that always comes to mind is how we have three species of Canis living together in East Africa; all the jackals are the same size, but occupying different niches and different habitat preferences. I’m not sure how readily we can distinguish the skeleton of one jackal species from another.

    I’ve always found it tempting to think of small theropods like dromaeosaurs, compsognathids and troodontids being far more speciose than they appear to be. In my speculative Late Cretaceous world, there are multiple species of Velociraptor, Troodon, or Dromaeosaurus, each occupying a different part of the continent, a la northern and southern species, or separated by habitat preference, like desert or woodland species.

  2. #2 Laelaps
    July 14, 2008

    Hai; Therein lies the rub with figuring out species by skeletal morphology. The general concept of a species is often placed in terms of breeding, but with the fossil record we have no such luck. There are probably were a lot more of what we would call species than we can recognize through skeletons alone. Comparative morphometrics can be useful in figuring some of this out but there’s only so far I can imagine it going if species is often defined in terms of things that don’t fossilize. Still, in the case of this paper, if there are the same lizards everywhere and most species are shared it makes the presence of a barrier dubious. We definitely need some more of the new Velociraptor to figure out just how different it was.

  3. #3 Zach Miller
    July 14, 2008

    Boy, it’s based on a single maxilla? And it’s got more (and larger) neurovascular foramina? I say new GENUS, sir!

    *sarcasm*

  4. #4 Alan
    July 14, 2008

    Very interesting. Is there any idea why they had this row of foramina for blood vessels/nerves along the jaw? Quite a few birds have whiscker/bristle like feathers around the mouth – did Velociraptor have similar whiskers? Whiskers seem to be imporatant for mammals – it would seem logical that dinosaurs might have had similar structures

  5. #5 David Marjanovi?
    July 15, 2008

    did Velociraptor have similar whiskers?

    What about lips?

The site is currently under maintenance and will be back shortly. New comments have been disabled during this time, please check back soon.