Found On Newcastle Ranch, 'Rex Jr.' Could Be Most Important T. Rex Ever Discovered

Key Points:

• "Rex Junior," a partial but perfectly preserved sub-adult Tyrannosaurus rex skeleton found on Wyoming's Zerbst Ranch, is expected to redefine scientific understanding of T. rex anatomy and physiology, with studies ongoing at the University of Chicago's Fossil Lab.
• Discovered in the 1990s and encased in extremely hard ironstone, Rex Junior includes the only complete T. rex forearm and hand ever found, as well as an articulated wishbone, which has led to revisions in the reconstruction of famous specimens like Sue at the Field Museum.
• The specimen is uniquely three-dimensionally preserved in a lifelike position, leading paleontologist Paul Sereno to propose that Rex Junior was buried alive during a sudden flood, rather than fossilized post-mortem.
• Contrary to expectations of scaly skin, Rex Junior shows no evidence of scales, suggesting new insights into T. rex integument that may align more closely with bird-like features; further details are pending publication.
• Alongside Rex Junior, other remarkable dinosaur mummies from the Zerbst Ranch, including a nearly complete Triceratops named "Lane," form a "triumvirate" of Late Cretaceous specimens that promise to transform knowledge of dinosaur biology and appearance in upcoming research releases.