A New Species of Daspletosaurus (Theropoda: Tyrannosauridae) from the Campanian of Southern Alberta Represented by a Growth Series of Well-preserved Skulls and Skeletons

MIYASHITA, T.; CURRIE, P. J.; PAULINA CARABAJAL, A.

Los Angeles

Congreso; Society of Vertebrate Paleontology annual meeting; 2013

Los Angeles County Museum y SVP

Many of the tyrannosaurines collected from the Campanian of western North America were identified as Daspletosaurus in the last four decades. In particular, discoveries of nearly a dozen well-preserved skulls and skeletons of Daspletosaurus from the Dinosaur Provincial Park and Oldman formations of Alberta led to the realization that these specimens represent a species distict from the type D. torosus. The new species of Daspletosaurus can be dfined on the basis of a nearly complete, three-dimentionally preserved, disarticulated skull (only missing the vomer) and an associated postcranial skeleton of an adul (Royal Tyrell Museum of Paleontology TMP 2001.36.1). The description is supplemented by information from juvenile and adult skulls and skeletons of th esame species. The new species is distinguished from D. torosus by characters that include the supranarial process of the premaxilla extending posteriorly fro more than half the diameter of the external naris, a lacrimal that is 1.5 times anteroposteriorly longer than dorsoventrally tall, a pronounced temporal margin of the postorbital and a maxillary tooth count greater than 15. The new species is from the Dinosaur Park Formation and the chronologically equivalent part of the Oldman Formation, and lived more recentrly than D. torosus.