Terrific Tetanurae! #1 Kelmayisaurus petrolicus

Time for a new series!

Many of you dinosaur-devotees out there may have heard of the elusive Kelmayisaurus, a large carcharodontosaurid dinosaur from Xinjiang province of western China. You’ve also probably heard that it’s the LARGEST THEROPOD OF ALL FREAKING TIME! Well, I’m going to try to disprove that in this post. Kelmayisaurus is only known from very scant remains, and because of this Kelmayisaurus is thought to be a nomen dubium. The species I will review  in this post is Kelmayisaurus petrolicus, as K.gigantus” is so poorly documented. Kelmayisaurus petrolicus is known from a complete left dentary  and a poorly-preserved piece of the left maxilla. The dentary of K. petrolicus is 523 millimeters in length. By comparing the dentary of the more well documented carcharodontosaurid Acrocanthosaurus atokensis (821 mm for NCSM 14345) to the dentary of Kelmayisaurus, we can make an educated guess about the size of K. petrolicus. From these dentary measurements, we can conclude that the dentary length of K. petrolicus is 63.7% of  the dentary length of A. atokensis. We then find what 63.7%  of 11500mm (estimated length for NCSM 14345) is. We get 7325.5 mm, or 7.3255 meters. For those of you unfamiliar with the metric system, that’s around 24 feet. Of course, this method is flawed in many ways, one of which being that the dentary of A. atokensis is not by any means a perfect scaled-up model of the Kelmayisaurus dentary. This method only gives us a (very) rough estimate of  the size of K. petrolicus. What it does show is that, based on it’s relatives, K. petrolicus was no giant. Rather, it was a medium-sized carcharodontosaurid, and nothing much out of the ordinary.


Kelmayisaurus petrolicus by the author. Pencils on paper, 2015.

Kelmayisaurus petrolicus by the author.


1. Stephen L. Brusatte, Roger B.J. Benson and Xing Xu.2012. “A Reassessment of Kelmayisaurus petrolicus, a Large Theropod Dinosaur from the Early Cretaceous of China”. Bioone.org. Accessed February 10, 2015. http://www.bioone.org/doi/full/10.4202/app.2010.0125

2. Currie, P. J. & Carpenter, K. 2000. “A new specimen of Acrocanthosaurus atokensis (Theropoda, Dinosauria) from the Lower Cretaceous Antlers Formation (Lower Cretaceous, Aptian) of Oklahoma, USA”. Accessed February 10,2015. Geodiversitas 22(2): 207-246.

3. Eddy DR, Clarke JA (2011) New Information on the Cranial Anatomy of Acrocanthosaurus atokensis and Its Implications for the Phylogeny of Allosauroidea (Dinosauria: Theropoda). PLoS ONE 6(3):e17932. doi: 10.1371/journal.pone.0017932

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