Researchers have named the new species Crocodylus lucivenator, or Lucy's hunter.
The poodle-sized reptile that lived over 200 million years ago was among creatures that had features similar to dinosaurs it lived beside.
The "miniscule" new fossil was discovered 500 miles south in Colorado’s Denver Basin.
Ants and other species who lived alongside dinosaurs but preserved in fossilized tree resin reveal a great deal about their roles.
Scientists described the discovery as a "palaeontological Rosetta Stone”.
The "astonishing" first indisputable evidence of a new species of Spinosaurus in over a century was found in a remote desert location.
The discovery shows that ancient vertebrates had a far more complex visual system than previously thought.
Analysis of fossils from South America shows that the tropical snakes reached their maximum size 12.4 million years ago.
