PhysOrg.Com has an interesting item on research presented to the Royal Society on October 20th. The research concerns microwear analysis on australopithecine teeth. The research specifically focuses on Australopithecus afarensis (woohoo, take that Ardipithecus)
Filed under: Australopithecus, Australopithecus afarensis, Hominini, Paleoanthropology | Tagged: Australopithecus afarensis, Australopithecus africanus, Australopithecus anamensis, Paranthropus boisei, Paranthropus robustus | 1 Comment »
I’ve been meaning to mention this ever since the article was published in PLoS One.
Brucellosis is an infectious disease caused by any of several bacilli. It is primarily found in livestock such as cows, horses, pigs, and goats. It has also been found in wild animals such as zebra, eland, waterbuck, and impala. It is primarily transmitted to humans via infected dairy products and meat. In humans the disease appears as a chronic infection of the lungs and recurring fevers. Males are affected more than females. The primary center of skeletal involvement occurs in the spine. Ortner and Putschar define the lesion involved as follows:
The lesion is a lytic cavitation. Grossly and on X-ray, it frequently can be seen penetrating the vertebral end-plate and extending through the nucleus pulposus of the disc into the next vertebral body … The cancellous bone within the focus is destroyed without formation of significant sequestra. The cortex also may be perforated, leading to parosteal abscesses. There is usually very little, if any, reactive bone formation except in the healing phase … In contrast to tuberculosis, which it resembles in several ways, complete collapse of vertebrae with gibbus formation is usually not observed … and paravertebral abscess is rare …
Hyenas are amazing animals. It takes a single hyena less than two minutes to consume an entire Thompson’s gazelle. A pack of 21 hyenas was able to polish off a 220 kg zebra and a 150 kg foal in about 30 minutes. An extinct species of borophagine dog (Borophagus) was probably able to accomplish similar feats as well. Borophagines, being descended from canids, retained post-carnassial molars. This pushed the carnassials forward in the jaw and they are located in the region of maximum bite force production and is what allowed them to crack bones efficiently using their carnassials (the carnassials are composed of a blade-like upper fourth premolar and a somewhat blade-like lower first molar). In hyenas, however, post-carnassial molars underwent a reduction and hyenas crack bones between their upper and lower third premolars not with the carnassials, which are behind the region of maximum bite.