''Mesomys'' is a genus of

South American South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

spiny rats 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 ecologically diverse, with members ranging from fully arboreal to terr ...

. The genus name ''Mesomys'' derives from the two

ancient greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic p ...

words (), meaning "middle of, between", and (), meaning "mouse, rat". It refers to the fact that this rodent — literally the "middle mouse" — has been considered as an intermediate form related both to mice and jumping rats.

Extant Species

Phylogeny

''Mesomys'' is a member of the

Echimyini Echimyini is a tribe of echimyid rodents, proposed in 2016, and containing 13 extant genera: all of the tree rats '' Echimys'', '' Phyllomys'', '' Makalata'', ''Pattonomys'', '' Toromys'', '' Diplomys'', '' Santamartamys'', and '' Isothrix'', th ...

clade of

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 ...

Echimyidae rodents. The closest relative of ''Mesomys'' is ''Lonchothrix'', reflecting the fact that these taxa have once been classified in the Eumysopinae, a subfamily now recognized as an artificial assemblage. These two genera share phylogenetic affinities with several taxa and clades: (i) ''Echimys'', ''Phyllomys'', ''Makalata'', ''Pattonomys'', and ''Toromys'' ; (ii) the bamboo rats ''Dactylomys'', ''Olallamys'', ''Kannabateomys'' together with ''Diplomys'' and ''Santamartamys'' ; and (iii) ''Isothrix''.

References

{{Taxonbar, from=Q911378 Rodent genera Taxa named by Johann Andreas Wagner