Trinomys is a genus of South America

South America

South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...

n spiny rat

Spiny rat

The spiny rats are a group of hystricognath rodents in the family Echimyidae. They are distributed from central Central America through much of South America. They were also found in the West Indies until the 19th century...

s in the family Echimyidae.

Extant species of Trinomys according to Natureserve

Trinomys albispinus	White-spined Atlantic Spiny-rat
Trinomys dimidiatus	Soft-spined Atlantic Spiny-rat
Trinomys eliasi	Elias' Atlantic Spiny-rat
Trinomys gratiosus	Gracile Atlantic Spiny-rat
Trinomys iheringi	Ihering's Atlantic Spiny-rat
Trinomys mirapitanga	Dark-caped Atlantic Spiny-rat
Trinomys moojeni	Moojen's Atlantic Spiny-rat
Trinomys myosuros	Mouse-tailed Atlantic Spiny-rat
Trinomys paratus	Spiked Atlantic Spiny-rat
Trinomys setosus	Hairy Atlantic Spiny-rat
Trinomys yonenagae	Spiked Atlantic Spiny-rat

The species of spiny rats in the genus Trinomys are apparently all Brazilian. In particular many of them are endemic to the Atlantic Forest of southeastern Brazil. Not much is known for certain about their ranges

Range (biology)

In biology, the range or distribution of a species is the geographical area within which that species can be found. Within that range, dispersion is variation in local density.The term is often qualified:...

 however, which still are being investigated, with frequent extensions to the recorded distributions of several species in various ecological classes of forest and dry land. They do not however appear to occur at high altitudes, and several of their ranges appear to be parapatric .