Palaeontologists have uncovered a new Thalattosuchian—an ancient “cousin” of modern-day crocodile—which could be the oldest of its kind ever discovered.
They are colloquially referred to as marine crocodiles orsea crocodiles, though they are not members of Crocodilia and records from Thailand and China suggest that some members lived in freshwater.
The clade contains two major subgroupings, the Teleosauroideaand Metriorhynchoidea. Teleosauroids are not greatly specialised for oceanic life, with back osteoderms similar to other crocodyliformes.
Within Metriorhynchoidea, the Metriorhynchidaedisplayed extreme adaptions for life in the open ocean, including the transformation of limbs into flippers, the development of a tail fluke, and smooth, scaleless skin.
The new discovery:
The newly-discovered fossils of Turnersuchus hingleyae represent the only complete Thalattosuchian of its age and date back to the early Jurassic, Pliensbachian period, which was about 185 million years ago.
The fossils uncovered on the Jurassic Coast in the United Kingdom include part of the head, backbone, and limbs of Turnersuchus hingleyae.
Significance:
The discovery of this new fossil helps fill a gap in the fossil record and suggests that Thalattosuchians and other crocodile-like animals could have originated around 15 million years farther than Turnersuchus.