125 million years ago a small crocodilian was living in our regions alongside the famous iguanodons. Now, the skull of ‘the small Bernissart crocodile’ has been scanned. As a result, palaeontologists place Bernissartia fagesii close to the base of the evolution of modern crocodiles.
From 1878 to 1881 museum workers and miners in Bernissart (province of Hainaut) discovered, besides some thirty iguanodons, an entire ecosystem of 125 million years ago: ferns, conifers, a cicada, fish (3000 specimens), a salamander, six turtles and … four crocodiles. Two big specimens are around two metres long and two tiny specimens are around sixty centimetres long.
Based on a nearly complete specimen, the tiny crocodiles were described and named Bernissartia fagesii by Louis Dollo in 1883. Since then, Bernissartia fossils have been found in Great-Britain, Spain and France. It is one of the smallest crocodiles ever known. The well-preserved specimen is displayed in our Dinosaur Gallery.
A Clearer View
Belgian, French and Italian scientists have CT-scanned the skull of Bernissartia (X-ray radiography). The micro-scanner allowed researchers to look through remains of sediment and thick protective glue, and through the fossils. In this way new details were revealed. After they compared all the details with other fossil crocodilians, the team including our palaeontologist Thierry Smith could determine the place of this animal in the evolutionary tree.
Based on 345 anatomical characters, palaeontologists place this tiny crocodile close to the beginning of the evolution of modern crocodilians (Eusuchia) some 145 million years ago (Early Cretaceous). On the scans, the palaeontologists perceived a mixture of primitive and more derived characters (notably, the choanae, the internal nostrils, appear more like in modern crocodiles). Bernissartia was part of a group of crocodiles presenting a range of characters providing palaeontologists more insight into the origins of extant crocodiles.
Koumpiodontosuchus aprosdokiti is another species among the family Bernissartidae. Adult specimens are also small. It was first described in 2014 based on a skull found on the Isle of Wight. According to this study, those extinct crocodiles were not close relatives of Atoposauridae, Paralligatoridae and Goniopholididae, as opposed to previous findings.
Omnivorous
New details on the teeth confirm that Bernissartia was not picky when it came to food. With its flattened rear teeth, it could crush shellfish such as freshwater snails and mussels, as well as insects and crayfish. With its sharp front teeth, it probably tore up small vertebrates like frogs and lizards. The diet corresponds to what biologists expect from small crocodiles.
The study was published in Journal of Systematic Palaeontology.
