Fossils belonging to a previously unknown species of human relative have been discovered in a cave system northwest of Johannesburg, South Africa, an international team of scientists announced Thursday.

The discovery of Homo naledi is expected to shed new light on the human family tree , according to a written statement released by the National Geographic Society, the University of Witwatersrand, and the South African Department of Science and Technology.

What's more, the fossils seem to indicate that H. naledi deposited the bodies of its dead in a remote part of the cave -- a behavior previously believed to have been practiced only by humans . In all, an astonishing 1,550 fossils belonging H. naledi were found in the Rising Star cave system .

"There are over 1,500 hominin fossils and not a single other fossil from a large African mammal. That was the first indication that this locality was unusual and the absence of other fossils is an important piece of evidence that this accumulation of bodies was deliberate," Jeremy DeSilva, an associate professor of anthropology at Dartmouth College in New Hampshire and a co-author of a paper describing the new species, told The Huffington Post in an email. "It was stunning, and an absolute thrill, to work with such a large collection of hominin fossils."

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