Phascolotherium is a genus of extinct eutriconodont mammal from the Middle Jurassic of the United Kingdom.

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.

[3] More than one specimen was given to Buckland, and one of these lower jaws was lost, but found again in 1827 by William Broderip,[2] and thought by Charles Lyell to be evidence that mammals dated from the earliest times without having changed.

[4] 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 Amphitherium.

[2][5] A second species, P. simpsoni was named from specimens from the Kirtlington mammal bed and Watton Cliff, both of the Forest Marble Formation in 2016.