Andrej Čerňanský during his recent fieldwork at Svalbard, a Norwegian archipelago in the Arctic Ocean. He was digging up plants high above the Arctic Circle that grew in forests there more than 55 million years ago. (source: Courtesy of Andrej Čerňanský)
Slovak palaeontologist Andrej Čerňanský from Comenius University in Bratislava is continuing to shed more light on long-extinct animals. Last year he co-authored a study on a new species of gecko representing an archaic lineage that survived the asteroid impact that wiped out the dinosaurs 66 million years ago. Now he's back with another discovery.
A Slovak-Belgian team of scientists has unearthed fossils of a reptile in Belgium that until now was known only to have lived in North America. It probably got into Europe by crossing a land bridge that appeared in the Atlantic Ocean for a few million years.
The Eocene (56 to 34 million years ago) is a very interesting geological epoch and these fossils date from the beginning of this epoch, from the time of the warmest global climate of the past 200 million years. Since we know very little about the early Eocene epoch, which spanned 22 million years, this find offers another piece of the puzzle.
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'A small tank'
The research team, led by Čerňanský, worked with scientists from Royal Belgian Institute of Natural Sciences and reported the fossils from Dormaal, a locality in eastern Belgium, in a recent study.
What is what – and when it was
The Mesozoic Era lasted from about 252 to 66 million years ago. It is comprised of the Triassic (252-201 million years ago), Jurassic (201-145) and Cretaceous (145-66) Periods.
The Mesozoic is followed by the current Cenozoic Era. Its first period is called the Paleogene (66-23), which is comprised of the Paleocene (66-56), followed by the Eocene (56-34) and finally the Oligocene (34-23) epochs.
Among the many reptiles so far found are glyptosaurids, an extinct group of reptiles that looked like small armoured tanks. Their bodies were covered by osteodermal shields, which are bony deposits found on the skin of many reptiles to this day. They have a typical granular structure. Glyptosaurids lived in North America when dinosaurs roamed the planet during the Cretaceous period from 145 to 66 million years ago. It was at the end of the Palaeocene - beginning of the Eocene, subdivisions of the Palaeogene, that they migrated, thanks to the warmer climate at that time, and spread to what is now Europe and Asia.
However, it was assumed that only a few glyptosaurids lived in Europe, in particular the genus Placosaurus, fossils of which have been found, mainly in France. These date from the late Eocene, i.e. from around 38 to 34 million years ago.
