Unraveling the Mystery: Is it a Young T. rex or a New Species? The 'Duelling Dinosaur' Fossil's 40-Year Debate Resolution
The world of paleontology has long been captivated by the iconic Tyrannosaurus rex, but a recent study has ignited a new debate that could potentially end a 40-year-long discussion.
For decades, scientists have debated the existence of multiple tyrannosaur species in North America during the late Cretaceous period. A pivotal discovery in the 1940s, a small skull believed to belong to a juvenile T. rex, further fueled this controversy.
Now, a groundbreaking analysis of the controversial 'Duelling Dinosaurs' fossil has brought new insights. This fossil, unearthed in 2006, features two dinosaurs: an almost complete Triceratops horridus and a tyrannosaur dubbed 'Bloody Mary'.
The tyrannosaur in question, estimated to be around 5 meters tall and weighing approximately 700 kilograms, has sparked intense debate. Initially thought to be a juvenile T. rex, further examination revealed it to be a different species, Nanotyrannus or 'tiny terrors'.
The study's lead author, Lindsay Zanno, emphasized the controversy surrounding the topic, stating, 'The debate has raged for decades, largely due to the lack of well-preserved skeletons of Nanotyrannus lancensis'.
The 'Duelling Dinosaurs' fossil provides crucial evidence, as it is the first complete skeleton of Nanotyrannus lancensis. This discovery challenges decades of T. rex research, as it significantly differs from the expected characteristics of a juvenile T. rex.
The research team identified multiple reasons why the fossil didn't fit the criteria for a juvenile T. rex. They found growth rings on the dinosaur's femur bone, indicating it was around 20 years old and nearly fully grown when it died. Additionally, the specimen's spine had begun to fuse, which would not occur at the onset of a rapid growth spurt.
The fossil also showcased Nanotyrannus' unique features, such as more teeth and distinct skull nerve and sinus structures, rendering it biologically incompatible with T. rex.
Stephen Poropat, a paleontologist at Curtin University, highlighted the elongated forearms of the Nanotyrannus as a key differentiator. He compared it to a human child having longer arms as a child than as an adult.
This debate is not new, as paleontologist Pete Larson noted in 2013 that the tyrannosaur's arm length and tooth count indicated Nanotyrannus. However, the fossil's private ownership at the time hindered further research.
Now, with the fossil in scientific hands, the study provides a detailed argument supporting the distinction between the two species. Dr. Poropat expressed confidence in the findings, but also acknowledged the possibility of ongoing discussions.
While this study offers a compelling case, Dr. Poropat and Dr. Zanno emphasize the need for further research. With an 'anatomical roadmap' now available, scientists can better identify and study Nanotyrannus fossils, which are already present in US museums. This exciting development promises to shed more light on the biology of these ancient creatures.
