Ihering's Spiny Rat

Trinomys iheringi is a medium-sized rat, with an average head and body length of 191 millimetres (7.5 in) with a 171 millimetres (6.7 in) tail. They weigh about 209 grams (7.4 oz). The fur on the top of the body is "cinnamon-buff", which lightens to white on the stomach. The tail has a brown base and white tip. Like other spiny rats, the coat is mixed with long stiff furs, or spines, about 21 millimetres (0.83 in) in length along the back. T. iheringi has 30 pairs of standard chromosomes, as well as a variable number of additional "dot-like" supernumerary chromosomes. It is found in Atlantic rainforest in Brazil, near the coasts, in the states of Sao Paulo and Rio de Janeiro. The Rio de Janeiro population, located on the island of Ilha Grande, is genetically distinct, and may represent a separate species. The two populations diverged about 0.6 million years ago, possibly due to glacial cycling occurring at the time. They have unusually large home ranges for rodents of their size, an average of 1.37 hectares (13,700 m2) for males and 0.86 hectares (8,600 m2) for females. The females reach full maturity at approximately eight months, and the lifespan is up to 30 months. They can reproduce year-round, but more commonly do so during the rainy season. …