How the Tyrannosaurs Ruled the World – with David Hone

Dave Hone, a paleontologist, expresses his excitement about returning to the Royal Institution. He introduces 'Queenie,' a replica of a Tyrannosaurus specimen from the Smithsonian. Despite being a model, it represents an important paleontological subject. The Tyrannosaurus is a well-studied dinosaur, often chosen as a starting point for new research due to the extensive knowledge already available. This has led to a significant understanding of the species, with many specimens available for study, each showing subtle variations. The lecture aims to explore the depth of knowledge on Tyrannosaurus and the diversity within the species.

The Tyrannosaur family, with about 30 species, is highlighted for its diversity in size and shape. The presenter discusses the range of Tyrannosaurus specimens from various locations, including North America, Asia, and even the UK, emphasizing the global distribution of the group. The talk touches on the difficulty in distinguishing between species from fragmentary fossil records and the potential for undiscovered species. The evolution of Tyrannosaurs is traced from small, early species to the giant T-Rex, showcasing the changes in body structure and adaptations that occurred over millions of years.

Key characteristics that unite Tyrannosaurs as a group are explored, such as the fused nasal bones and the unique 'D-shaped' teeth at the front of the jaw. These features are consistent across all known Tyrannosaurs and distinguish them from other theropods. The strong build of the skull, indicative of a powerful bite, is also discussed. The presenter uses various examples to illustrate the evolutionary changes in Tyrannosaurs, from smaller ancestors with long arms and tails to the massive T-Rex with tiny arms and a robust body.

The Tyrannosaurus's skull is described as having forward-facing eyes, indicating it was a carnivore capable of judging distances—a trait not found in herbivores. The large size of the Tyrannosaurus's eyes suggests excellent vision, even in the dark, surpassing that of any known terrestrial animal. The width of the skull is also noted, with comparisons to other large carnivores, emphasizing the broad head of the Tyrannosaurus as a unique feature.

The presenter discusses the rapid growth of Tyrannosaurus, with a specific growth spurt occurring between 10 to 20 years, resulting in a significant increase in size. The change in shape during growth is also highlighted, with juveniles having a smaller head, longer legs, and a slender body compared to adults. This suggests a change in behavior and ecology as the dinosaur matures. The Tyrannosaurus's foot structure is also explored, with a unique adaptation known as the 'octo-metatarsal' condition, which would have made the dinosaur an efficient long-distance runner.

The Tyrannosaurus's skull and teeth are compared to those of other large carnivores, emphasizing the solid bone structure and the powerful build of the T-Rex. The large size and robustness of the teeth, with serrated edges, are indicative of the dinosaur's immense bite power. Evidence of Tyrannosaurus teeth leaving marks in solid bone is presented, demonstrating the strength and effectiveness of the bite. The lecture also touches on the debate between Tyrannosaurus being a predator or a scavenger, suggesting that it was likely both, based on the available evidence.

The feeding behavior of Tyrannosaurus is discussed, with evidence suggesting that they were selective feeders, targeting specific parts of their prey. The presenter describes a hadrosaur fossil with numerous bite marks from a Tyrannosaur, indicating a feeding event. The pattern of bites suggests that the Tyrannosaurus used its upper teeth to scrape meat off the bone. Another fossil with a Tyrannosaurus tooth embedded in it provides further evidence of predation. The lecture also addresses the scavenging behavior of Tyrannosaurus, with one example showing evidence of the dinosaur scavenging on a dead hadrosaur.

The global distribution and evolutionary history of Tyrannosaurs are summarized, with evidence of their presence on multiple continents and their existence for approximately 100 million years. The presenter mentions recent discoveries of new species and the ongoing research in the field. The adaptations of Tyrannosaurs, including their eyesight, running abilities, and evidence of feathers in some species, are also discussed. The conclusion emphasizes that Tyrannosaurs were opportunistic predators and scavengers, with a complex understanding of their behavior and biology continuing to evolve as new specimens are discovered.

The presence of feathers in early Tyrannosaurs, such as Dilong and Yutyrannus, is discussed. The discovery of feather impressions in these fossils challenges the notion that large dinosaurs like T-Rex would not have had feathers. The presenter suggests that feathers may have been a common feature across the Tyrannosaur lineage, and it is only a matter of time before evidence of feathers in T-Rex is found. The lecture concludes with a summary of the current understanding of Tyrannosaurus, emphasizing their role as model organisms in paleontological research.