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 Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

, where it occurs in the

flooded forest Freshwater swamp forests, or flooded forests, are forests which are inundated with freshwater, either permanently or seasonally. They normally occur along the lower reaches of rivers and around freshwater lakes. Freshwater swamp forests are found ...

along the banks of the

Amazon River The Amazon River (, ; es, Río Amazonas, pt, Rio Amazonas) in South America is the largest river by discharge volume of water in the world, and the disputed longest river system in the world in comparison to the Nile. The headwaters of t ...

and its tributaries. This species was formerly considered to be a member of the genera ''Loncheres'' and ''

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 ...

''. In 2005 it was reclassified as the only member of the new genus ''Toromys''. The etymology of the genus name derives from the onomatopoeic Portuguese word , referring to the vocalizations of this rodent, and the

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 peri ...

word (), meaning "mouse, rat".

Phylogeny

''Toromys'' is the sister genus to ''Pattonomys''. These taxa are closely related to ''Echimys'', ''Phyllomys'', and ''Makalata'', reflecting the fact that '' Toromys grandis'' and '' Pattonomys occasius'' have formerly been placed in ''Makalata'' by some authorities. In turn, these five genera share phylogenetic affinities with a clade containing the bamboo rats ''Dactylomys'', ''Olallamys'', ''Kannabateomys'' together with ''Diplomys'' and ''Santamartamys''.

References

Echimyidae Mammals described in 1845 Endemic fauna of Brazil Taxa named by Johann Andreas Wagner {{Echimyidae-stub