Tyrannosaurus rex ancestor discovery in Utah

From PLOS ONE:

Tyrant Dinosaur Evolution Tracks the Rise and Fall of Late Cretaceous Oceans

Mark A. Loewen,

Randall B. Irmis,

Joseph J. W. Sertich,

Philip J. Currie,

Scott D. Sampson

Abstract

The Late Cretaceous (~95–66 million years ago) western North American landmass of Laramidia displayed heightened non-marine vertebrate diversity and intracontinental regionalism relative to other latest Cretaceous Laurasian ecosystems. Processes generating these patterns during this interval remain poorly understood despite their presumed role in the diversification of many clades.

Tyrannosauridae, a clade of large-bodied theropod dinosaurs restricted to the Late Cretaceous of Laramidia and Asia, represents an ideal group for investigating Laramidian patterns of evolution. We use new tyrannosaurid discoveries from Utah—including a new taxon which represents the geologically oldest member of the clade—to investigate the evolution and biogeography of Tyrannosauridae. These data suggest a Laramidian origin for Tyrannosauridae, and implicate sea-level related controls in the isolation, diversification, and dispersal of this and many other Late Cretaceous vertebrate clades. …

Work in the Kaiparowits Basin of southern Utah has recovered abundant new fossils critical for testing such patterns, including the oldest-known tyrannosaurid and the most complete tyrannosaurid specimen discovered from southern Laramidia (Fig. 1). The phylogenetic and biogeographic implications of the new taxon from the Wahweap Formation (~80 Ma), together with a nearly complete skeleton of the poorly understood Teratophoneus curriei [13] from the overlying Kaiparowits Formation (~76 Ma), are examined in the context of the isolation and dispersal of Laramidian vertebrates during the latest Cretaceous.

Related articles

• Tyrannosaurus rex excavation update (dearkitty1.wordpress.com)
• Mongolian dinosaurs’ eggs discovery (dearkitty1.wordpress.com)
• ‘Longhorn’ Dinosaur Fossil Discovered in Utah (livescience.com)
• The Truth About T. Rex (nature.com)
• T. Rex Tooth Found in Dinosaur’s Tail Proves Tyrannosaurus Was a Predator (westerndigs.blogspot.com)
• Tyrannosaurus rex skeleton to the Netherlands (dearkitty1.wordpress.com)
• The Dinosaurs in My Yard (zocalopublicsquare.org)
• Tell-tale toes point to oldest-known fossil bird tracks from Australia (eurekalert.org)
• Meet the ‘big-nosed horned-face’ dinosaur (nbcnews.com)
• It’s Official: T. Rex Was Ferocious Predator, Not Scavenger (livescience.com)

Advertisements