Know Your Hominin: A.L. 666-1

A.L. 666-1 was discovered in 1994 in Hadar, Ethiopia. It dates to ~2·33 MYA and has been attributed to Homo habilis. A number of Oldowan flakes and choppers were found as well.

(From Kimbel et al 1996)

Literature

Kimbel et al 1996 Late Pliocene Homo and Oldowan Tools from the Hadar Formation (Kada Hadar Member), Ethiopia. Journal of Human Evolution 31: 549–561

Kimbel et al 1997 Systematic Assessment of a Maxilla of Homo From Hadar, Ethiopia. AJPA 103:235–262

Know Your Hominin OH-65

OH-65 was found in 1995 in the Upper Bed I at Olduvai Gorge. It dates to 1.942-1.785 mya. OH-65 is a nearly complete maxilla that has been attributed to Homo habilis. It’s morpholoogy is similar to that of KNM-ER 1470 and the authors of the paper announcing the find use that similary to make two arguments.

First:

This overall concordance of the ER 1470 and OH 65 morphologies with that of the type specimen of H. habilis casts doubt on H. rudolfensis as a biologically valid taxon. Consequently, H. rudolfensis (Alexeev) Groves would be a junior synonym for H. habilis Leakey, Tobias, and Napier …

Second:

The architectural similarities between OH-65 and ER 1470 support the judgement that late Pliocene hominids from Olduvai Gorge and East Lake Turkana usually assigned to H. habilis instead represent more than one species…

On the surface these seem to be contradictory arguments unless they are arguing that because H. rudolfensis is a junior synonym for H. habilis the species in the H. rudolfensis group have to be named something else. At any rate, below is a picture of OH-65.
(Picture Source)

Literature Cited

Blumenschine et al 2003 Late Pliocene Homo and Hominid Land Use from Western Olduvai Gorge, Tanzania
Blumenschine et al 2003 Late Pliocene Homo and Hominid Land Use from Western Olduvai Gorge, Tanzania Supplemental Online Material

Begging For Articles: Asian Australopithecines

Can someone with access send me the following articles:

A critical analysis of claims for the existence of Southeast Asian australopithecines, Journal of Human Evolution Volume 26, Issue 1, Pages 3–21 http://dx.doi.org/10.1006/jhev.1994.1002

Meganthropus, australopithecines and hominids, American Journal of Physical Anthropology Volume 11, Issue 1, pages 1–38, DOI: 10.1002/ajpa.1330110112

Further remarks on the relationship between “Meganthropus” and australopithecines, American Journal of Physical Anthropology Volume 13, Issue 3, pages 429–445, DOI: 10.1002/ajpa.1330130304

My email address is on the about page.

Some Random Thoughts About Australopithecus sediba

I am going to be very busy today so I won’t get an in depth post up on Australopithecus sediba until tomorrow. In the meantime three items jumped out at me so I thought I would, briefly, mention them.

Things You Would Like To See

Science Daily has an item concerning the Laetoli foot print study in PLoS One. One bit stands out:

The subjects walked both with normal, erect human gaits and then with crouched, chimpanzee-like gaits.

Film of the latter would be interesting – lord knows we were disappointed with last year’s Ardipithecus special on that score… Speaking of, why is the idea that some of our ancestors were bipedal on the ground but still spent a lot of time in the trees news?

And then there is this (also from Science Daily):

This morphology differs distinctly from our own genus, Homo, who abandoned arboreal life around 2 million years ago and irrevocably committed to human-like bipedalism.

I guess Homo habilis don’t count, eh? I hope the PLoS One article is better (I haven’t read it yet).

Were Crocodiles Responsible For The Stones We Call Tools?

Bob O’H brings an interesting Correspondence item in Nature to our attention. An excerpt is below:

Know Your Anthropology Literature: Ecobotanical Contexts for African Hominids

Ecobotanical Contexts for African Hominids, by O’Brien and Peters, was published in a book edited by J. Desmond Clark entitled Cultural Beginnings: Approaches to Understanding Early Hominid Life-Ways in the African Savanna.
O’Brien and Peters describe the work they are doing on a project called “Survey of the Wild Edible Plants of Africa”. The point of the survey is to assemble as much information as possible on plant species used by baboons, chimpanzees, and humans in Africa. The eventual inclusion of plants used by gorillas was also mentioned.

Evolution of Human Limb Proportions: Part Two

As I mentioned in Part One The OH62 femur plays an important role in any discussion of the evolution of human limb proportions.

Looking at the above picture, several things should be noticed. First, the head and a small portion of the neck are missing. Second, the shaft extends to a little past the nutrient foramen (although you can’t really see this in the picture – for those unfamiliar with osteology the nutrient foramen is an opening for the passage of blood vessels and bone). Third, there is a significant amount of bone exfoliation. In order to determine femur length an estimation needs to be made.

Evolution of Human Limb Proportions: Part One

Humans have interesting limbs. Unlike in the apes, the humerus is shorter than the femur but longer than the radius. In chimps and gorillas the humerus is longer than the femur and radius. In orangutans and gibbons the humerus is longer than the femur but shorter than the radius. There are several measures anthropologists use to make these determinations. One, the humerofemoral index ([humerus x 100]/femur) measures the ratio of humerus to femur. In humans the mean of this index is (approximately) 71, in chimps 101, gorillas 116, orangutans 130 and in the gibbon 116. To compare the humerus and radius the brachial index ([radius x 100]/humerus) is used. Mean values are: humans 74, chimps 92, gorilla 80, orangutan 100 and gibbon 110. Since humans and chimps share a, relatively, recent common ancestor presumably some evolution has occured in limb proportions. We can look at the postcranial skeletons of a few hominids to determine a rough time line. Australopithecus afarensis, for example, has a humerofemoral index of about 84 (largely attributed to a smaller femur) and a brachial index of about 91 (larger radius relative to humerus). In Homo erectus, on the other hand the humerofemoral index is approximately 73 and the brachial index is 79 or roughly the same as in modern humans. So, during the course of human evolution there have been changes in forearm proportions and in femur length. For quite a while this was interpreted as an example of gradualism in hominin evolution. Then, the fly in the ointment was found.