STL Science Center

STL Science Center

17 March 2012

3 Species of Tupuxuara

©M. Shiraishi
Tupuxuara as a genus contains three species; T. longicristatus, T. leonardii, and T. deliradamus. All three species have long rear swept crests on top of their heads. Typically, however, the only illustrated models that we see are of T. longicristatus. This species has a high bulbous crest extending behind the skull beginning with a forward attachment site above and forward of the nares on the nasal bone of the skull. These crests swooped backwards at a fairly consistent angle until it was above the shoulders of the pterosaur. The crest then arced back down in a large oval shape to attach again at the rear of the skull on the post occipital. The coloration of such crests is barely if at all known or evident in fossil evidence, and so the illustrations we have could all be completely correct or completely incorrect.

©Tuomas Koivurinne
T. leonardii's crest is slightly different. The crest follows the same general lines of design and formation, however, it is not as smooth as the crest of T. longicristatus. The lower trailing edge of the crest above the shoulders is not as rounded either. The body shape of the three species overall is very similar with the wings very much alike in all lines indicating that the crest was the largest difference in flight mechanics. The crest may not have been really used in flight, but any small head motion in a high wind situation would cause deviation from straight level flight with the crests of these species as they would have diverted airflow. In fact, if the head was used to aid in flight at all, it would have made a very spectacular rudder system.

The last species, T. deliradamus, has the shortest crest by far. The crest actually only truly begins as separate from the regular skull bones in the occipital area but the end of the loop of the crest is the same as the other two species. If the head is indeed used as a rudder in flight then T. deliradamus would have had the flight with the most control at high speeds as only slight movements of the head would be required in order to adjust the flight path of the animals.

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