Two new specimen have been found in a chamber at the Sterkfontein Caves, Witwatersrand University said on Thursday.

The specimen, a finger bone and a molar, are part of a set of four specimens associated with early stone tools dated to 2.18-million years ago, the institution said.

“The specimens are exciting not only because they are associated with early stone tools, but also because they possess a mixture of intriguing features that raise many more questions than they give answers,” said lead researcher, Dr Dominic Stratford, who is also a lecturer at the University of the Witwatersrand (Wits) School of Geography, Archaeology and Environmental studies.

He added that the first specimen, a very large proximal finger bone, was significantly larger and more robust than any other hand bone yet found in South Africa.

“It is almost complete and shows a really interesting mix of modern and archaic features. For example, the specimen is markedly curved, more curved than Homo Naledi and is similarly curved to the much older species Australopithecus afarensis,” Stratford said.

The other fossil is a relatively small and nearly an complete adult molar tooth. Stratford said it also bears a resemblance of two of the 10 molars in size and shape of the Homo naledi, although further detailed comparisons were needed to verify that.

“The shape of the tooth and particularly the shape and relative sizes of the cones on the surface of the tooth suggest this specimen belonged to an early member of the Homo genus and can be associated with early stone tools dated recently to 2.18-million years ago.”

The Sterkfontein caves, situated at the world heritage site, the Cradle of Humankind in the north west of Johannesburg, are one of the leading palaeoanthropological sites in the world.

Some famous finds included Ms. Ples, Little Foot and more recently, Homo naledi.

Starford said further excavations were planned to find more pieces and to find out who the bones belonged to and how they lived and died on the Sterkfontein hill more than two million years ago.