Tyrannosaurus rex Tooth Progression Partial Dentary Styracosaurus The rock contains the detritus

The rock contains the detritus of shells and corals of species now inhabiting the neighboring sea (some of the coral still retaining the same red color now seen in reefs of living coral which surround the island)

It dates from the late Cretaceous period

The baby teeth are needle sharp for snagging insects

(Homo erectus)

and either simple or forking at outer end

Tyrannosaurus rex Tooth Progression Partial Dentary Styracosaurus The rock contains the detritusAge: Late Cretaceous Maastrichtian ~ 65 MYA Locality: Hell Creek Formation, Harding County, South Dakota This reconstruction, showing Tyrannosaurus rex tooth progression, provides a fascinating look inside the tooth regeneration process of the most fierce predator North America has ever hosted. The exterior of the dentary is intact, while the interior provides an open window to the innermost actions taking place. The Theropod dinosaurs regrew their