A new study reveals we still don’t know everything about giraffes—and what we don’t know could entirely change how conservationists protect them.

Currently, giraffes are all know as species Giraffa camelopardalis, and up to 11 sub-species are recognized, including the Nubian giraffe (Giraffa camelopardalis camelopardalis). But skin biopsies on 190 giraffes from all around Africa revealed that they are about as genetically distinct as a polar bear is from a black bear, the study’s lead author, Axel Janke, told Chris Woolston for Nature.

The authors of this new study, published last week in Current Biology, suggest that giraffes should be divided into four distinct species: the southern giraffe (G. giraffa); the Masai giraffe (G. tippelskirchi); the reticulated giraffe (G. reticulata); and the northern giraffe (G. camelopardalis). The Nubian giraffe would remain a recognized subspecies. By definition, the four newly defined species cannot breed with each other in the wild.

The big question, Janke told Woolston, is what kept giraffes apart so long that they developed into separate species. He thinks it’s possible that physical barriers like rivers kept populations separated for enough time for new species to arise.

The giraffe has been under-studied, according to Giraffe Conservation Foundation (GCF), receiving less attention than other large African animals like elephants, rhinoceroses, gorillas and lions.

The work of Janke and his colleagues reveals some important conservation concerns for giraffes. If considered under their suggested taxonomic system, an already-small total giraffe population of approximately 80,000 individuals drops to less than 10,000 individuals of two of the new species, Woolston writes.

Dr. Julian Fennessy of GCF is an author on the recent paper. He notes in the GCF release that the northern giraffe has fewer than 4,750 individual giraffes in the wild, while the reticulated giraffe number less than 8,700. “As distinct species, it makes them some of the most endangered large mammals in the world and require doubling of protection efforts to secure these populations,” he says.

The genome of the giraffe was first decoded earlier this year—revealing clues about why the giraffe, the tallest mammal, has such a long neck and long legs. There may still be much more to learn about these majestic beasts lurking in their genes.