A team of Brazilian and Belgian scientists have discovered one of the rarest species of mammals on the planet. The team, including the VUB and Belgian Royal Institute of Natural Scientists researcher Philippe Kok, has found another Roraima mouse. The Institute made the announcement on Tuesday. This discovery was made a little by accident in November 2009, on the summit of tepui Wei-Assipu in Guyana (Latin America). After catching the animal and doing a DNA analysis, the researchers found the closet species to this very rare little mouse are animals that live in a very different region, thousands of kilometers away. This mouse lives in a very small territory. Only six species of Roraima mouse were known before Philippe Kok’s 2009 discovery. There were all captured in 1927 and 1989, in the same place: the summit of tepui Mount Roraima, on the border between Guyana, Venezuela and Brazil.
The tepuis are enormous table-shaped mountains that loom over Savannas and tropical forests. The fauna in these unique territories is considered quite isolated, therefore its evolution is the subject of vey targeted scientific research. According to current theories, the little mammals that live on the tepuis come from “either populations from the Andes that spread over long distances, or invasions from the higher grounds and plains around the tepuis”, says the institute.
The DNA analysis on the 7th Roraima mouse discovered in 2009, and its genetic comparison with other species, suggests an evolution that doesn’t fit these theories. It would suggest “a connection between the Guyana shelf (where the tepuis are) and the Brazilian shelf”, which “developed 2,47 million years ago”. According to the Belgian and Brazilian researcher’s findings, the closest species genetically to the little tepui mice are two taxa (Thalpomys and Necromys), which live in the Savannas of the Brazilian shelf.
Maria Novak (Source: Belga)