Echimyini is a tribe of
echimyid 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 (), meaning ...
'', ''
Phyllomys'', ''
Makalata
''Makalata'' is a genus of rodents in the family Echimyidae.
Systematics
The etymology of this genus name derives from a combination of letters inspired by the Suriname native name ''Maka-alata'' for spiny rats.
This genus contains the followin ...
'', ''
Pattonomys'', ''
Toromys
The giant tree-rat (''Toromys grandis'') is a species in the family Echimyidae, the spiny rats. It is the only species in the monotypic genus ''Toromys''. It is endemic to Brazil, where it occurs in the flooded forest along the banks of the Ama ...
'', ''
Diplomys'', ''
Santamartamys'', and ''
Isothrix'', the long recognized dactylomines ''
Dactylomys'', ''
Olallamys'', and ''
Kannabateomys'', and the enigmatic and previously classified as eumysopines ''
Lonchothrix
The tuft-tailed spiny tree rat (''Lonchothrix emiliae'') is a spiny rat species from Brazil south of the Amazon River, where it has been found in grassland and gallery forest. It is the only species in the genus ''Lonchothrix''.
Very little is ...
'' and ''
Mesomys''.
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 num ...
. Worth of note, the arboreal genus ''
Callistomys'' – the painted-tree rat – does not belong to the tribe Echimyini. Because it is phylogenetically closer to ''
Myocastor'', ''
Hoplomys'', ''
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 recogni ...
'', and ''
Thrichomys'' than to the above-mentioned Echimyini genera, it is classified in the tribe
Myocastorini.
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