Many scientists regard these creatures as ancestors of both the lineage that led to modern humans and of another, now-extinct evolutionary lineage known as robust australopithecines.
afarensis evolved into the relatively small-brained, large-jawed robust australopithecines but didn't contribute to the evolution of modern people, says anthropologist Yoel Rak of Tel Aviv University.
Falk argues that the robust australopithecines avoided the hot expanses of savanna and instead frequented wooded areas near lakes and rivers, where they mainly munched nuts and seeds (SN: 7/2/88, p.
Thus, he argues, Falk inappropriately uses only one anatomical feature -- venous drainage patterns--to group Lucy and other Hadar hominids with robust australopithecines.
Connecting the nasal bones, he reported, was a keystone-shaped pattern of sutures that characterizes only robust australopithecines, also known as Paranthropus, as well two other distinct suture patterns marking modern apes and humans.
This configuration of sutures appears to be a normal variation in facial structure and part of the common heritage of hominoids, or apes and humans, and is not confined to robust australopithecines, concludes Eckhardt in the July 23 NATURE.
Various scientists have speculated that the teeth enabled robust australopithecines to eat tough foods, such as nuts, hard fruits, and the seeds of grasses.
5 million years ago, when robust australopithecines thrived.
Researchers usually view the robust australopithecines as a dead-end lineage comprising three species--one in South Africa and two in East Africa--that lived between 2.
Most facial traits of robust australopithecines arose as developmental by-products of their unusual set of teeth, she proposes.
58) and was either related to or a direct ancestor of the later robust australopithecines
Clarke says some of the specimenshave larger teeth and flatter faces and brows, indicating that they were an ancestral stock for both southern and eastern robust australopithecines