Echimyini is a tribe of

echimyid Echimyidae is the family of neotropical spiny rats and their fossil relatives. This is the most species-rich family of hystricognath rodents. It is probably also the most ecologically diverse, with members ranging from fully arboreal to terres ...

rodents, proposed in 2016, and containing 13 extant genera: all of the tree rats ''

Echimys ''Echimys'' is a genus of the spiny rats family, the Echimyidae. Members of this genus are collectively called spiny tree-rats. The genus name ''Echimys'', and also its synonym ''Echinomys'', derive from the two Ancient Greek words (), meani ...

'', ''

Phyllomys ''Phyllomys'' is a genus of arboreal spiny rat, geographically restricted to the forests of eastern Brazil. The etymology of the genus name derives from the two ancient greek words (), meaning "plant leaf", and (), meaning "mouse, rat". Phy ...

'', '' Makalata'', ''

Pattonomys ''Pattonomys'' is a genus of rodent in the family Echimyidae Echimyidae is the family of neotropical spiny rats and their fossil relatives. This is the most species-rich family of hystricognath rodents. It is probably also the most ecologi ...

'', '' Toromys'', ''

Diplomys ''Diplomys'' is a genus of rodent in the family Echimyidae. They are found in Costa Rica, Ecuador, Colombia and Panama. Systematics The genus contains the following species: * Colombian soft-furred spiny rat (''Diplomys caniceps'') * Rufous soft ...

'', ''

Santamartamys The red-crested tree-rat or Santa Marta toro (''Santamartamys rufodorsalis'') is a species of tree-rat found in the monotypic genus ''Santamartamys'' in the family Echimyidae. It is nocturnal and is believed to feed on plant matter, and is mainly ...

'', and ''

Isothrix The toros or brush-tailed rats, genus ''Isothrix'', are a group of spiny rats found in tropical South America, particularly in the Amazon Basin.Nowak, Ronald M. 1999. ''Walker's Mammals of the World'', 6th edition. Johns Hopkins University Pres ...

'', the long recognized dactylomines ''

Dactylomys ''Dactylomys'' is the genus of South American bamboo rats They are arboreal members of the family Echimyidae. Systematics The genus name ''Dactylomys'' derives from the two Ancient Greek words (), meaning "finger", and (), meaning "mouse, rat" ...

'', ''

Olallamys ''Olallamys'' is a genus of Andean soft-furred spiny rat that range from Panama through Colombia and Venezuela to northern Ecuador. These species are typically found at elevations above . Systematics ''Olallamys'' is a taxonomic patronym hono ...

'', and '' Kannabateomys'', and the enigmatic and previously classified as eumysopines '' Lonchothrix'' and ''

Mesomys ''Mesomys'' is a genus of South American spiny rats in the family Echimyidae. The genus name ''Mesomys'' derives from the two ancient greek words (), meaning "middle of, between", and (), meaning "mouse, rat". It refers to the fact that this ...

''. All these spiny rats genera are

arboreal Arboreal locomotion is the locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally, but others are exclusively arboreal. The habitats pose nu ...

. Worth of note, the arboreal genus ''

Callistomys The painted tree-rat (''Callistomys pictus'') is a species of spiny rat from Brazil, restricted to north-eastern Bahia in eastern Brazil. It is the only species in the genus ''Callistomys''. Identification With a total length of ca. 30 cm ...

'' – the painted-tree rat – does not belong to the tribe Echimyini. Because it is phylogenetically closer to ''

Myocastor ''Myocastor'' is a genus of rodent that contains the living nutria (or coypu), as well as several fossil species. Taxonomy Due to similar cranial morphology, the nutria was once considered a close relative of the Caribbean hutias and placed toge ...

'', ''

Hoplomys The armored rat (''Hoplomys gymnurus'') is a species of rodent in the family Echimyidae. It is monotypic within the genus ''Hoplomys''. It is found in Latin America, from northern Honduras to northwest Ecuador. It possesses a range of spines on ...

'', ''

Proechimys ''Proechimys'' is a genus of South American spiny rats of the family Echimyidae. All species of the genus are terrestrial. In the lowland Neotropical forests, ''Proechimys'' rodents are often the most abundant non-volant mammals. They are recog ...

'', and ''

Thrichomys ''Thrichomys'' is a genus of South American rodents in the family Echimyidae. It contains at least five species, found in Bolivia, Brazil and Paraguay. They are as follows: * Common punaré (''Thrichomys apereoides'') * Foster's punaré (''Thri ...

'' than to the above-mentioned Echimyini genera, it is classified in the tribe

Myocastorini Myocastorini is a tribe of echimyid rodents, proposed in 2017, and containing the five extant genera '' Callistomys'', '' Hoplomys'', '' Myocastor'', ''Proechimys ''Proechimys'' is a genus of South American spiny rats of the family Echimyida ...

Phylogeny

Five assemblages can be distinguished in the genus-level

cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to ...

of Echimyini: * ''Echimys'' is closely related to ''Phyllomys'', ''Makalata'', ''Pattonomys'' and ''Toromys''. This clade is in accordance with the fact that ''Phyllomys'' was classified within ''Echimys'', and that ''Pattonomys'' and ''Toromys'' were placed in ''Makalata''. * ''Dactylomys'', ''Olallamys'', and ''Kannabateomys'' share unique features, and these South American bamboo rats are grouped under the informal clade name of "Dactylomyines". * ''Diplomys'' and ''Santamartamys'' are sister group, reflecting the fact that the latter genus has been split from the former. * ''Lonchothrix'' and ''Mesomys'' are sister group, and have often been classified within "Eumysopines", a subfamily otherwise shown 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 conver ...

. * ''Isothrix'' occupies an isolated, deep-branching position.

References

{{Taxonbar, from=Q48839418 Echimyidae