Pseudictopidae is an extinct family of

mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...

s closely related to

rodent Rodents (from Latin , 'to gnaw') are mammals of the Order (biology), order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and Mandible, lower jaws. About 40% of all mammal specie ...

s and

lagomorph The lagomorphs () are the members of the taxonomic order Lagomorpha, of which there are two living families: the Leporidae (rabbits and hares) and the Ochotonidae ( pikas). There are 110 recent species of lagomorph, of which 109 species in t ...

s. Members of the family are known from

Paleocene The Paleocene ( ), or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), ...

Eocene The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...

deposits in China and Mongolia.

Taxonomic history

The family Pseudictopidae was erected in 1969 by Andrez Sulimsky as a

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unisp ...

family, with '' Pseudictops'' as the type and only genus, though later authors would assign more genera to the family. Sulimsky tentatively assigned Pseudictopidae to

Eutheria Eutheria (from Greek , 'good, right' and , 'beast'; ), also called Pan-Placentalia, is the clade consisting of Placentalia, placental mammals and all therian mammals that are more closely related to placentals than to marsupials. Eutherians ...

incertae sedis or is a term used for a taxonomy (biology), taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertainty ...

'', believing that it and

Anagalidae Anagalidae is an extinct family of mammals closely related to rodents and lagomorphs. Members of the family are known from Paleocene to Oligocene The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Peri ...

were representatives of an unknown order. In 1971, Szalay and McKenna erected the order

Anagalida Anagaloidea is a former order of extinct placental mammals that first appeared during the Paleocene epoch. Taxonomy According to the traditional (morphological) view, Anagaloidea is part of the superorder Anagalida, along with the elephant shrew ...

, to which Pseudictopidae was assigned.

References

Anagaloidea Prehistoric mammal families Paleocene first appearances Eocene extinctions {{Paleo-mammal-stub