BPP University paleontologist Matthew Baron has identified a previously unknown carnivorous dinosaur from Dorset, England based on fossils collected in the 1850s.
An artist’s impression of Dornraptor normani. Image credit: Megan Williams.
Dornraptor normani is believed to have lived during the Early Jurassic epoch, around 200 million years ago.
This new species is an averostran, a large group that includes most theropod dinosaurs, namely ceratosaurs and tetanurans.
“Dornraptor normani represents a ‘more derived’ theropod than those already named from the Early Jurassic of England,” Dr. Baron wrote in his paper.
Two partial yet distinctive hindlimbs of Dornraptor normani were discovered in the Blue Lias Formation in Dorset, England.
“Originally this material was referred to the early armored ornithischian taxon Scelidosaurus harrisonii, which had also been recovered from a Lower Jurassic Formation in Southern England,” the paleontologist wrote.
“However, this error in assignment was soon realized and corrected in subsequent works, and the material in question reclassified as an indeterminate theropod.”
“More recent works have suggested possible neotheropod or even tetanuran affinities for at least some of this material, but no consensus has yet been reached about its true phylogenetic and taxonomic affinities.”
“The material has never been formally named, even though the material does appear to display a distinct combination of anatomical characteristics.”
“Our study re-appraises the two specimens, compares, and contrasts them with other known Triassic and Early Jurassic theropods, and tests their possible phylogenetic affinities using three different anatomical datasets: two that are heavily theropod focused and one more general early dinosaur focused.”
“The results of these analyses, in combination with the anatomical comparisons presented herein, suggest that this fragmentary material could represent a distinct, early occurring, and early branching averostran neotheropod.”
According to the study, Dornraptor normani constitutes one of the oldest known theropod dinosaurs from the United Kingdom. Only the early diverging coelophysoid theropod Pendraig milnerae is known from older layers.
“This conclusion therefore adds to our current understanding of early theropod evolution and distribution within the United Kingdom and Europe more broadly and suggests the presence of Averostra in England during the Early Jurassic,” Dr. Baron wrote in the paper.
“This taxon seems to have been a contemporary of other, non-averostran theropods, as well as a numerous other vertebrates, including at least one thyreophoran ornithischian dinosaur, and this picture of Early Jurassic terrestrial fauna is consistent with other localities of a similar age globally.”
“We see a similar combination of early ornithischians/possible thyreophoran ornithischians and early branching averostran theropods in the La Quinta Formation of Venezuela, for example, i.e., Laquintasaura venezuelae and Tachiraptor admirabilis.”
“Finally, our study also emphasizes the benefit of constantly reappraising material housed in historic collections.”
“Our broader understanding of non-avian dinosaur diversity and distribution throughout the Mesozoic can be expanded not just with new discoveries in the field, but also with such reappraisal and fresh analyses of older materials.”
“Hitherto hidden patterns of diversity and disparity within existing collections may continue to be uncovered as more powerful analytic tools and datasets become available and more new taxa named and described for comparison.”
“It is only by constant reappraisal of known material, often in light of new discoveries, that we can ever truly understand the true richness of the global fossil record.”
The paper was published online in the journal Palaeontologia Electronica.
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Matthew G. Baron. 2024. A new name for old bones: A reassessment of Early Jurassic theropod remains from Dorset, England. Palaeontologia Electronica 27 (1): a25; doi: 10.26879/1346
