New From Jeff Martz - Poposaurus in Color; and the Question of Bipedality in Animals with a Crocodile-normal Ankle Type

Jeff Martz has recently colo(u)rized his Poposaurus gracilis reconstruction and here it is in its new glory.

When I see reconstructions of pseudosuchians in a bipedal stance I always reflect upon the question of whether or not it is functionally possible for an animal with a crocodile-normal ankle type to actually be bipedal, especially an obligate biped.  I've perused the literature but have found very little to address this problem. I'm certain that Emma Schachner dealt with this in her recently completed PhD on the new equisitely preserved Poposaurus specimen from the Chinle Formation in Utah, but unfortunately I've not had a chance to borrow and read a copy.  Her 2009 SVP abstract suggests that myological developments differ between bipedal pseudosuchians and bipedal dinosaurs, suggesting that these myological changes compensate for the alternate ankle structures.

What Did Triassic Pseudosuchians Eat? Little Ornithodirans of Course!

Here is another scene from the new mural by Victor Leshyk at the Rainbow Forest Museum at Petrified Forest National Park.  In this scene two silesaurs are chased (and one is caught) by a hungry Postosuchus. I just find it so fitting that the tables are turned and it is the dinosaurians getting their due rather than those cool aetosaurs which are always depicted as prey or dead in most Late Triassic themed murals.

Don't Get Too Close to the Water!

The Rainbow Forest Museum at Petrified Forest National Park has a new mural depicting a scene from the lower part (Blue Mesa Member) of the Chinle Formation.  The mural was completed by Sedona artist Victor Leshyk (who also did the Museum of Northern Arizona's therizinosaur exhibit). The centerpiece of this new mural (at least in my eyes) is this moment when an unwary ornithodiran gets a little to close to the rivers edge and becomes a meal for the true rulers of the North American Triassic. I apologize for the poor lighting in the exhibit room (which isn't completely finished yet), but welcome everyone to check out this new scene when you visit the Park.

New Triassic Critter Reconstruction II

Here is another new Late Triassic critter reconstraction from the Chinle/Dockum courtesy of Jeff Martz. As with the last one I'll leave the ID up to you with discussion to follow.

New Triassic Critter Reconstructions

Not only is Jeff Martz a really good geologist and paleontologist he also is very skilled as an illustrator (check out his M.S. thesis Martz [2002], his skeletal reconstruction of Desmatosuchus [from Parker, 2008], and this link at Discovery News for other examples of his work). Jeff has recently initiated a new series of Late Triassic animal reconstructions from Petrified Forest National Park and has generously offered to let me share some of them on my site rather than showing them on his site. The park has been sorely lacking up-to-date reconstructions of many of its Triassic animals, as most existing reconstructions date from the 1980s and do not include the majority of new finds. This is the first of the series and I won't tell you what taxon this is. Instead I'll leave to you to guess its identity.
These represent slightly different reconstructions of the same animal. It is challenging to try to provide realistic yet thought provoking reconstructions, especially regarding skin color, texture, and soft tissue. The coloration and patterning of most animals fall into a few broad catagories including camouflage, disruptive patterning, and/or sexual display. The animal featured here is most likely a carnivore and thus was provided with more of a disruptive pattern that would allow the animal a mechanism to distract prey by making the body outline hard to see, and thus distance and speed difficult to judge. The upper reconstruction adds hypothesized soft parts including a 'dewlap' and other features which may or may not have been present, and thus are speculative yet feasible for display.

As long as Jeff is willing, I hope to provide more of these new reconstructions in the future.

REFERENCES

Martz, J.W. 2002. The morphology and ontogeny of Typothorax coccinarum (Archosauria, Stagonolepididae) from the upper triassic of the American Southwest. Unpublished M.S. thesis. Texas Tech University, Lubbock.

Parker, W.G. 2008. Description of new material of the aetosaur Desmatosuchus spurensis (Archosauria: Suchia) from the Chinle Formation of Arizona and a revision of the genus Desmatosuchus. PaleoBios , 28:1-40.