Pliosaur tooth, giant marine reptile Troodon The type species is M

The type species is M

Specimens are known to have been made of flint

They were first found and described by John Locke in 1838

Study of the fossils of such animals can provide information on the evolution of humans

The density of specimens in the Aspidella beds suggests levels of benthic biomass in the Neoproterozoic that could rival those of modern marine communities

Pliosaur tooth, giant marine reptile Troodon The type species is MPLIOSAURUS(pronounced PLY oh SAWR us) Pliosaurus (meaning "greater lizard") was a huge, short necked plesiosaur that lived during the middle to late Jurassic period. This carnivore was a flippered marine reptile (a pliosaur and a plesiosaur, but not a dinosaur) with many sharp teeth in large, powerful jaws resembling those of a crocodile; the teeth were three sided in cross section. It was 33 40 ft (10 12 m) long and the skull was 5 6. 6 ft (1. 5 2 m)