Hairy Atlantic spiny rat

The hairy Atlantic spiny rat is a spiny rat species from South America.

Taxonomy

described it in 1817 as Proechimys setosus. It was moved to Trinomys by Lara and Patton in 2000.

It is a medium-large rat, with a head and body length averaging and a tail. The fur on the back is "brownish-olive to cinnamon", gradually paling to white on the stomach. The tail has a brown base and white tip, with a tuft of hair at the end.
They have 56 pairs of chromosomes. A 2022 genetic analysis found that within Trinomys, T. setosus is most closely related to T. yonengae, and they may have separated approximately 8 million years ago.
The species is endemic to Brazil, and can be found in Sergipe, Bahia, Minas Gerais, Espírito Santo, and Rio [de Janeiro (state)|Rio de Janeiro]. Its habitat includes forest and savanna. It is likely nocturnal.
The IUCN list T. setosus as a species of least concern due to its wide distribution and local abundance.