''Phascolotherium'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of extinct

eutriconodont Eutriconodonta is an order of early mammals. Eutriconodonts existed in Asia, Africa, Europe, North and South America during the Jurassic and the Cretaceous periods. The order was named by Kermack ''et al.'' in 1973 as a replacement name for the p ...

mammal from the Middle Jurassic of the United Kingdom. Found in the Stonesfield Slate, it was one of the first

Mesozoic The Mesozoic Era ( ), also called the Age of Reptiles, the Age of Conifers, and colloquially as the Age of the Dinosaurs is the second-to-last era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Cretace ...

mammals ever found and described, although like the other mammal jaws found at the same time, it was mistakenly thought at first to be a marsupial.Broderip W.J. 1828. Observations on the jaw of a fossil mammiferous animal found in the Stonesfield Slate. Zoological Journal of London 3, 408–412

Discovery

''Phascolotherium'' was one of the first mammals described from

-aged rocks. It is only known from single lower jaws and some isolated teeth. Buckland showed the fossil jaws of Stonesfield to the exceptional comparative anatomist, Georges Cuvier, who incorrectly identified them as marsupials, based on the similarity of the bones to modern marsupials. Blainville also attributed the fossil to his newly erected genus,

Amphitherium ''Amphitherium'' is an extinct genus of stem cladotherian mammal that lived during the Middle Jurassic of England. It was one of the first Mesozoic mammals ever described. A recent phylogenetic study found it to be the sister taxon of ''Palaeoxo ...

. More than one specimen was given to Buckland, and one of these lower jaws was lost, but found again in 1827 by William Broderip, and thought by Charles Lyell to be evidence that mammals dated from the earliest times without having changed. However, British comparative anatomist Richard Owen later recognized the Stonesfield fossils as being distinct from opossums and from another mammal found in the same rocks, named ''

''. The new genus ''Phascolotherium'' was given to ''"D." bucklandi''. A second species, ''P. simpsoni'' was named from specimens from the Kirtlington mammal bed and Watton Cliff, both of the

Forest Marble Formation The Forest Marble is a geological formation in England. Part of the Great Oolite Group, it dates to the late Bathonian stage of the Middle Jurassic.Weishampel, David B; et al. (2004). "Dinosaur distribution (Middle Jurassic, Europe)." In: Weisha ...

in 2016.Percy M. Butler; Denise Sigogneau-Russell (2016). "Diversity of triconodonts in the Middle Jurassic of Great Britain" (PDF). Palaeontologia Polonica. 67: 35–65. doi:10.4202/pp.2016.67_035.

References

Eutriconodonts Bathonian life Middle Jurassic mammals of Europe Jurassic England Fossils of England Fossil taxa described in 1838 Taxa named by Richard Owen Prehistoric mammal genera {{jurassic-mammal-stub