Who likes teeth? Better yet, who doesn't like teeth. Anyway, I should have posted this yesterday when I first saw the pics, but since I am pretty cool like this, I waited until today. Thanks once again to the daily new reports of Archaeology.org for tipping me to this news story.

From the Cleveland Museum of Natural History and Drs. Yohannes Haile-Selassie and Bruce Latimer come a new discovery from this year's field season in the Afar region of Ethiopia. Below is a quote from the press release:

Scientists working in the Woranso-Mille area of the Afar Region, Ethiopia, have recovered fossils that may prove to be a bridge to establishing a relationship between the earlier Australopithecus anamensis (4.2 - 3.9 million years) and the later Australopithecus afarensis (3 - 3.6 million years) early human species. Researchers have hypothesized an ancestor-descendant relationship between these two species based on their similarities. However, until now, there has been no hominid fossil record from the 3.6 - 3.9 million years time frame to determine this relationship. “We recovered fossil hominids that date to between 3.5 and 3.8 million years ago,” said Haile-Selassie. “These specimens sample the right time to look into the relationship between Australopithecus anamensis and Australopithecus afarensis and will play a major role in testing the ancestor-descendant hypothesis.” The project team found isolated teeth from this time frame during its earlier field seasons. However, during the 2007 field season, they recovered more complete jaws that are important to conduct comparative analysis.

This discovery is wonderful on many levels. We (well, not me) have been looking for fossils from the time frame between the two species mentioned above, in the time frame between 3.9 and 3.6 Ma. Fossils in this time frame could prove whether or not the two species are related. Secondly, we have teeth!! At the top of the page are two of the specimens found from the Ale Dora and Leado Dodo'a localities, respectively. Both of those specimens are probably from Australopithecus afarensis and you can click on the images for their normal size. The one of the left side of the screen preserves the mandibular dentition from LP4 through RM3, and they look somewhat unworn except for the incisors. The lateral incisors seem to have broken off due to taphonomic processes and are not present above the cervix. I also do not see any pathologies; the individual was probably younger. Make note of the shape of the premolars, especially the P4's. Very cool, no? The right side picture preserves the maxillary dentition from what looks like RP3 to RM2. Just superior and medial to the rightmost tooth (RP3) in the picture looks like the root of the canine based on the size and canine jugum that would be present there. The rightmost tooth cannot be a canine because there is no canine jugum above it (nor a fossa behind it). The incisors were also broken off of this specimen. So sad. I love mamellons. Anyway, you are probably wondering, what is that large depression above the first molar in this pic? It looks like a nasal aperture, no? I thought the same thing at first glance before looking at the teeth at all. It is the space under the zygomatic process of the maxilla, aka the cheekbone. You can palpitate it on yourself. It was larger in our ancestors. The only pathology I see here is that the first molar is impacted! Very cool.



Here is one of the most complete lower jaws from before 3Ma! Once again, the anterior teeth are all broken off. So sad. Both sides of the mandible preserve the fourth premolar through the third molar. There is some wear there, so probably a young to middle adult. Unfortunately, whoever took the picture did it in sunlight (never a good idea) or had hell of a flash obscuring my view of the right side of the mandible. The first molar looks incomplete, but I cannot tell if that is from pathology or taphonomy. It also looks like we have six cusps on the third molars (tuberculum sextum). Damn, I love teeth!

Jason