Peradectes

The genus name is derived from the Greek for “pouch” (pera-) and “biter” (-dectes), indicating a marsupial thought to engage primarily in carnivory. ==Taxonomy and relationships==

The exact placement of Peradectes and its relationships have been uncertain. Some definitions of the group may be polyphyletic, and the extinct genus Thylacodon was thought by some to be synonymous with Peradectes; however, the two are now considered separate genera. It is known to be a metatherian and further a member of the crown clade Marsupialia along with other extinct and extant groups due to distinct marsupial dentition and jaw anatomy. Once thought to be a member of Didelphidae along with modern opossums, it is now classified within a separate family, Peradectidae, due in part to the predilambdodont, rather than true dilambdodont, upper molars. Some classifications recognize a subfamily within Peradectidae, Peradectinae, which includes at least Peradectes, Thylacodon, and Nanodelphys. Though no longer believed to be didelphids, the opossum-like Peradectes and its relatives in Peradectidae may represent a primitive step in the evolution of opossums. A “peradectid or peradectid-like ancestor” may have given rise to didelphids in the Cretaceous. ==Description==

As with other mammals, due to the hardness of the enamel, teeth and jaws make up much of the fossil record of Peradectes. The jaw of the type specimen P. elegans is slender with a medially inflected angle as in other marsupials like opossums, and it possesses simple premolars and comparatively large canine teeth. Some specimens are also described as having a robust skull with a short snout and vertical directed lower incisors. Peradectes fossils tend to be small, with individual teeth for example measuring no larger than 1.5 mm. One particular specimen assigned to Peradectes has postcranial anatomy common to modern arboreal marsupials, including reduced transverse processes of the lumbar vertebrae, a posterior anticlinal vertebra, somewhat short metatarsals, and a comparatively long tail (1.5-2 times the length of the head and body) thought to have been prehensile. ==Distribution==

Fossils of the group Peradectidae, of which Peradectes is a part, have been found primarily in the Northern Hemisphere. ==Palaeoecology==

The skeletal anatomy of Peradectes is consistent with at least a partially arboreal lifestyle. Analyses have also suggested a partially scansorial life mode (climbing but not necessarily living in trees) for at least some Peradectes species, along with frugivorous or insectivorous feeding. ==References==