A research team with Austrian participation found a previously unknown representative of the so-called hybodontiform sharks in fossils recovered from the coast of southern England around 20 years ago. The specimen, now baptized Durnonovariaodus maiseyi, swam through the shallow, tropical-subtropical sea around 150 million years ago. Since the skeletons of cartilaginous fish are otherwise rarely well preserved, the relatively comprehensive find is a rarity for the researchers.
The coast of County Dorset is one of the most important fossil sites for fossils such as hybodontiform sharks. This is one of the most species-rich groups of primeval sharks, which are also related to today’s rays and sharks, but disappeared along with the dinosaurs around 66 million years ago. The animals first appeared in the Devonian Age 361 million years ago.
Sebastian Stumpf from the Institute for Paleontology at the University of Vienna has been examining a special collection in the south of England for some time, as he explained to the APA, through a cooperation with English colleagues led by Charles Underwood. In the village of Kimmeridge there is a museum that houses the “Etches Collection”. This is one of the most important collections of fossils in England and the life’s work of the fossil collector Steve Etches, who is also the co-author of the description in the journal “PeerJ”.
Stumpf and colleagues actually came across the new way in the exhibition there. Because of its size, much of the collection has not yet been examined in detail. That Durnonovariaodus maiseyi must be “something completely new” caught the scientist’s eye relatively quickly.
If you usually find remains of primeval sharks, these are often only teeth, as nothing of the soft cartilage of the fish usually lasts for millions of years. Already the shape of the teeth drew the scientists’ attention, but remnants of the skull and parts of the rest of the skeleton were also preserved. Overall, the remains suggest a relatively large animal, perhaps two meters in length. The skeleton has numerous features “from species that are already known to us, but it shows a specific mosaic of different features,” said Stumpf.
In the “Kimmeridge Clay Formation” a comparatively large number of hybodontiform sharks has so far come to light; there was no evidence of the representative now described among the abundant fossils, such as individual teeth. This leads the researchers to speculate that the animal may have lived in deeper waters and that the species may only appear very rarely in the former shallow waters there. “That is, however, very speculative,” emphasized Stumpf.
Even after around 150 years of research, there are still some questions about the evolution of hybodontiform sharks. Stumpf and his British colleagues continue to analyze which findings are still slumbering in the “Etches Collection”. The paleontologist was convinced that further “sensational results” can be expected here.