The symposium ”The African Human Fossil Record’ took place last 26-27 of September at Toulouse, France. This post summarizes a selection of topics presented in this meeting, in alphabetical order per author. By the way… look at the event logo on the right, really nice!
Beaudet A. et al
Some on-going studies try to determine the chronology of key sites in the Crandle of Humankind:
- Swartkrans (first place where the co-ocurrence of early Homo and Paranthropus was recognized).
- Kroomdraai (which yielded the type specimen of Paranthropus TM 1517).
- Makapansgat (deposits of Australopithecus africanus remains dating to 3.0-2.6 MYA).
The initial results of the study show that Kromdraai dating could be closer to Makapansgat, thus older than previously thought, and that the deposits of Swartkrans are younger than 2 MYA.
Beaudet A. et al
A comparison of various South African hominid endocasts, to illustrate the diversity of traits coming from 3 effects:
- Intra-species variation during hominin radiation.
- Effects of homoplasy (non-phylogenetic-based resemblances).
- The impact of taphonomy on the fossilization process.
The presented results contrast with the expected characteristics of an early Homo endocast, such as: distinct Broca’s area, absence or faint presence of a lunate sulcus positioned posteriorly, unique orbitofrontal morphology, complex configuration of the middle meningeal network.
Bruner E. et al
A comparison between African and Asian endocasts of Homo erectus.
- The Asian samples display slightly larger values of cranial capacity, generally interpreted as a body/brain size increase and not as a process of encephalization.
- The Asian specimens tend to show bulging and projecting occipital lobes.
- No paleoneurological differences between African and Asian specimens were demonstrated in this study.
Crevecoeur I. et al
Analysis of a #Ish25, an upper first molar found in Ishango (Democratic Republic of Congo, Western Rift Valley). The study shows actually a correspondence with Plio-Pleistocene homininis (australopiths & early Homo) rather than post-Lower Pleistocene Homo as was originally assigned to.
This suggests that 2 MYA hominins expanded to the Western Rift Valley, which by then was a woodland to grassland area adjacent to dense lowland forests.
Daver G. et al
The Lower Pleistocene (2.4-1.8 MYA) is marked by the presence of the oldest‐known members of the genus Homo (2.3-2.4) in Eastern Africa and in Eurasia (1.8) at Dmanisi (Georgia), and the co-existence of multiple hominin taxa (Paranthropus, Homo and Australopithecus).
However, very few specimens of postcranial remains were found. One is a set of limb bones in the OMO 323 locality (Southern Omo Valley, Ethiopia) dated 2.14-2.12 MYA. This shows a form of bidepalism (metatarsal), in combination with climbing/suspensory behaviours (radius and phalanx) – which extreme morphologies making unlikely the attribution to Homo but possibly to Paranthropus boisei, due to the previous finding of remains of P. boisei cranium in OMO 323.
Fortes-Lima C.A. et al
Genetic and archaeological discussions on the possibility that the appearance of anatomically modern humans was accompanied by a speciation bottleneck about 190 KYA. Current phylogenetic studies of African mtDNA try to determine the potential contribution of archaic hominids to the modern human gene pool, and tackle the question of where in Africa this genesis took place.
Guy F. and Boisserie J.-R.
A new hominin partial edentulous mandible, OMO 333-10003, dated 2.74-2.58 MYA from the Shungura Formation, Omo Valley (Ethiopia), possibly in the dimensions ranged observed in Parathropus aethiopicus.
Hatala K.G. and Richmond B.G.
A comparison between the 1.5 Ma hominin footprints from Ileret, Kenya and the 3.7 Ma footprints from Laetoli, Tanzania.
The Ileret footprints are closer to modern humans and show morphological differences from the Laetoli ones. Both Ileret and modern humans show deeper impressions beneath the medial metatarsal heads and toes.
Joordens J. et al
Paleomagnetic and paleoenvironmental studies around paleolake Lorenyang in the Turkana Basin, where at least three groups were present: ‘1470 group’, ‘1813 group’ and early African Homo erectus/ergaster.
Patel B.A. et al
Comparison of a hallucal distal phalanx from Dmanisi, Georgia (D2670, dated 1.77 MYA) with a large sample of gorillas, chimps, modern humans and the only described early hallucal distal phalanx (OH10, attributed to Homo erectus).
Both D2670 and OH10 have a mixed morphology showing that early Homo may have had a functionally similar foot to modern humans, but its morphology still retained primitive features and may have differed within and out of Africa.
A contribution to the taxonomic allocation of the specimens of early Homo, a controversial debate since the discovery of the first specimens attributed to Homo habilis in the Olduvai Gorge in 1959 and extended with the finding of new specimens in East Africa (e.g. KNM-ER-62000, ER 62003, OH 65) and as well as the description of new taxa (Kenyanthropus platyops and Australopithecus sediba).
There are 100+ specimens allocated to early Homo, from these sites:
- Ethiopia: Hadar, Omo valley, Fejej.
- Kenya: West and East Turkana (Ileret, Koobi Fora), Chemeron.
- Tanzania: Olduvai.
- Malawi: Uraha.
- Republic of South Africa: Sterkfontein, Swartkrans, Drimolen.
4 hypotheses have been expressed for them:
- All belong to a single species Homo habilis with a high sexual, geographical and temporal variability
- The hypodigm is heterogeneous: 2 species could be defined in that group, Homo habilis sensu stricto (2.34‐1.34 MYA) and Homo rudolfensis (2.45‐1.8).
- They do not belong to Homo but to Australopithecus.
- Specimens of Homo rudolfensis fall into Kenyanthropus.
The study presented was based on the cranial specimens and shows:
- The taxonomical position of Au. Sediba could be debatable.
- The inclusion of the specimens of Homo habilis and Homo rudolfensis into the genus Australopithecus or Kenyanthropus is not supported by this analysis.