Dave Hone: T-Rex, Dinosaurs, Extinction, Evolution, and Jurassic Park | Lex Fridman Podcast #480

At ~12 meters and ~7+ tons with a killer‑whale‑sized body, massive bone‑crushing teeth, powerful tail‑driven locomotion, and energy‑efficient feet, T. rex likely ‘power‑walked’ up to ~20–25 mph and specialized in running down juvenile large herbivores rather than dueling giant adults.

Evidence from bite marks, healed wounds, and stomach contents shows large theropods typically targeted prey around 5–20% of their own mass—naive, poorly defended juveniles—matching patterns seen in modern predators like big cats and crocodiles.

Hone stresses that fossils are altered between death and discovery; interpreting pack hunting, scavenging, or sociality from bone beds or trackways requires testing alternative explanations (e.g., flood transport, predator traps, scavenging) and combining data from anatomy, bite marks, isotopes, and modern ecology.

The films reasonably portray T. rex’s size and gait, but misrepresent raptor size, pack hunting, T. rex vision, and many anatomical features; Hone argues it’s no harder or more expensive to make dinosaurs accurate, and that authenticity could strengthen both art and public understanding.

Independent evidence—crocodile‑like conical teeth, skull mechanics, isotopes, and preserved stomach contents—supports spinosaurs as fish-focused, water‑associated predators, but Hone sees weak support for claims that Spinosaurus was a proficient aquatic diver that could outfight T. rex.

Multiple dinosaur groups (tyrannosaurs, dromaeosaurs, ornithomimosaurs, etc.) show feather impressions back to the Middle Jurassic; birds evolved within theropod dinosaurs, so taxonomically they *are* dinosaurs, and feathers likely began for insulation and/or display before being co‑opted for flight.

Many theropods and ceratopsians sported crests, horns, or sails that likely functioned both in social/sexual signaling and in combat or defense; Hone emphasizes that traits rarely have a single function and that mutual sexual selection (both sexes ornamented) can imply shared parental investment or complex social life.