Wikipedia
Santamartamys is a monotypic genus of rodent in family Echimyidae, containing only the red-crested tree rat (Santamartamys rufodorsalis). It is nocturnal and is believed to feed on plant matter, and is mainly rufous, with young specimens having a grey coat. IUCN list the species as critically endangered: it is affected by feral cats, climate change, and the clearing of forest in its potential range in coastal Colombia.
It is known only from three specimens, a specimen collected in 1898 in Sierra Nevada de Santa Marta and identified by Herbert Huntingdon Smith, a specimen identified by the American ornithologist and entomologist Melbourne Armstrong Carriker in 1913 at the same location, and a further specimen observed in the same location in 2011. Found at altitudes of 700 to 2,000 metres, the species is endemic to Colombia in an isolated area with high levels of biodiversity. The species was initially identified as Isothrix rufodorsalis in 1899, re-classified as Diplomys rufodorsalis in 1935, and the monotypic genus Santamartamys was created in 2005 for the species.