Important New Hominid Fossil Described

[UTEOTW]

The journal Nature this week published a description of several new fossils from the raod to humanity.

The fossils are of Australopithecus anamensis. My understanding is this. Fossils of this species had been known before but these are new, in a slightly new area and are well dated. They expand the known range of the species in terms of morphology as well as geographic and temporal. They also highlight a critical time, the evolution of Australopithecus from Ardipithecus. Specifically, they are intermediate between Ar. ramidus and Au. afarensis.

But you do not have to depend on my impressions. Nature was kind enough to put the full text online for us.

http://www.nature.com/nature/journal/v440/n7086/full/nature04629.html

And from the press...

http://www.msnbc.msn.com/id/12286206/

And the abstract

The origin of Australopithecus, the genus widely interpreted as ancestral to Homo, is a central problem in human evolutionary studies. Australopithecus species differ markedly from extant African apes and candidate ancestral hominids such as Ardipithecus, Orrorin and Sahelanthropus. The earliest described Australopithecus species is Au. anamensis, the probable chronospecies ancestor of Au. afarensis. Here we describe newly discovered fossils from the Middle Awash study area that extend the known Au. anamensis range into northeastern Ethiopia. The new fossils are from chronometrically controlled stratigraphic sequences and date to about 4.1–4.2 million years ago. They include diagnostic craniodental remains, the largest hominid canine yet recovered, and the earliest Australopithecus femur. These new fossils are sampled from a woodland context. Temporal and anatomical intermediacy between Ar. ramidus and Au. afarensis suggest a relatively rapid shift from Ardipithecus to Australopithecus in this region of Africa, involving either replacement or accelerated phyletic evolution.

"Asa Issie, Aramis and the origin of Australopithecus," White et al., Nature 440, 883-889 (13 April 2006)