Anagaloidea is an extinct order of

placental mammal Placental mammals (infraclass Placentalia ) are one of the three extant subdivisions of the class Mammalia, the other two being Monotremata and Marsupialia. Placentalia contains the vast majority of extant mammals, which are partly distinguishe ...

s that first appeared during the

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), E ...

epoch In chronology and periodization, an epoch or reference epoch is an instant in time chosen as the origin of a particular calendar era. The "epoch" serves as a reference point from which time is measured. The moment of epoch is usually decided by ...

Taxonomy

According to the traditional (morphological) view, Anagaloidea is part of the superorder Anagalida, along with the

elephant shrew Elephant shrews, also called jumping shrews or sengis, are small insectivorous mammals native to Africa, belonging to the family Macroscelididae, in the order Macroscelidea. Their traditional common English name "elephant shrew" comes from a pe ...

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

s and

lagomorph The lagomorphs are the members of the taxonomic order Lagomorpha, of which there are two living families: the Leporidae (hares and rabbits) and the Ochotonidae (pikas). The name of the order is derived from the Ancient Greek ''lagos'' (λαγ� ...

s. However, the Anagalida are considered to be

polyphyletic A polyphyletic group is an assemblage of organisms or other evolving elements that is of mixed evolutionary origin. The term is often applied to groups that share similar features known as homoplasies, which are explained as a result of converg ...

. Genetic studies have shown that the elephant shrews are actually part of a different macro-group of mammals called the

Afrotheria Afrotheria ( from Latin ''Afro-'' "of Africa" + ''theria'' "wild beast") is a clade of mammals, the living members of which belong to groups that are either currently living in Africa or of African origin: golden moles, elephant shrews (also know ...

, while the position of several extinct families of Anagalida is uncertain. The

Zalambdalestidae Zalambdalestidae is a clade of Asian eutherians occurring during the Late Cretaceous. Once classified as Glires, features like epipubic bones and various cranial elements have identified these animals as outside of Placentalia, representing thus ...

are almost certainly unrelated to any of these groups; they probably represent more basal

Eutheria Eutheria (; from Greek , 'good, right' and , 'beast'; ) is the clade consisting of all therian mammals that are more closely related to placentals than to marsupials. Eutherians are distinguished from noneutherians by various phenotypic tra ...

ns and might not even be true Eutherians at all. The

Anagalidae Anagalidae is an extinct family of mammals closely related to rodents and lagomorphs. Members of the family are known from Paleocene The Paleocene, ( ) or Palaeocene, is a geological epoch that lasted from about 66 to 56 million years ago ...

and the Pseudictopidae probably represent a genuine

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

. This clade is known as the Anagaloidea, which seems to be related to the rodents and lagomorphs after all. Together they form the clade

Glires Glires (, Latin ''glīrēs'' 'dormice') is a clade (sometimes ranked as a grandorder) consisting of rodents and lagomorphs (rabbits, hares, and pikas). The hypothesis that these form a monophyletic group has been long debated based on morphologic ...

, often grouped with the

Euarchonta The Euarchonta are a proposed grandorder of mammals: the order Scandentia (treeshrews), and its sister Primatomorpha mirorder, containing the Dermoptera or colugos and the primates (Plesiadapiformes and descendents). The term "Euarchonta" (mea ...

to form the superorder

Euarchontoglires Euarchontoglires (synonymous with Supraprimates) is a clade and a superorder of mammals, the living members of which belong to one of the five following groups: rodents, lagomorphs, treeshrews, colugos, and primates. Evolutionary affinities wit ...

Classification

*Superorder Anagalida * **Order Anagaloidea ***Family

****Genus ''

Anagale ''Anagale'' is an extinct genus of mammal from the early Oligocene of Mongolia. Its closest living relatives are the rodents and lagomorphs. ''Anagale'' was 30 cm (1 ft) long and resembled a rabbit, but with a longer tail. Also, the b ...

'' ***Family Pseudictopidae ***Family

Astigalidae Astigalidae is an extinct family of mammals related to the rodents and lagomorphs. Members of the family are known from the Paleocene and Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago ...

? **Family

? ***Genus ''

Zalambdalestes ''Zalambdalestes'' (meaning ''much-like-lambda robber'') was a eutherian mammal, most likely not a placental due to the presence of an epipubic bone, living during the Upper Cretaceous in Mongolia. ''Zalambdalestes'' was a hopping animal with ...

References

Glires Cretaceous mammals Mammal orders Prehistoric animal orders {{cretaceous-mammal-stub