Tuesday, September 2, 2008

Chronological Bits - Crania

Quick chronological bits on Anatomically modern human specimens:

East Africa:

Omo I ~ 195, 000 years ago.

Other views of the Omo I specimen: These below give a very good indication of the scope of the missing sections of the actual skull, the remaining fragments of which have been mated to a carefully moulded pieceemulating the contours of the skull fragments where they are fittedto hold the fragments together and provide an intuitive idea of how the complete skull--had it been fully preservedwould have looked:

Below is a diagrammatic comparison between the skulls of Homo heidelbergensis, Omo I and a recent human respectively...

Herto Man ~ 165,000 years ago.


Qafzeh skull ~ 90,000 to 100,000 years ago.

Good link to Paleontology!

East Africa - Nile Valley:

Singa specimen, Sudan ~ anywhere from 100,000 to 150,000 years ago depending on what source a reader picks up [Chris Stringer & Grun (1991) puts the age at ~ 100,000 years ago, McDermott et al. (1996) put it between ~ 140,000 and 150,000 years ago]

The specimen was uncovered in 1924. Note the Singa specimen's extraordinarily broad bi-pareital width near the bosses; several observers [e.g. notably Chris Stringer] describe this condition as one of a pathological one, attributable to absence of bony labyrinth structures in the skull's temporal bone, on the right side; see...

"From Singa in the Sudan, there is another hominin, discovered in 1924. On the basis of U-Th dating of calcrete adhering to the bones, the Singa cranium is >133,000 years old. It has a domed frontal, a relatively high vault, and is very broad at the parietal bosses. Here, the parietals are thickened, mostly because of diploic expansion. Great biparietal width is perhaps related to pathology, because the Singa right temporal lacks structures of the bony labyrinth." - Rightmire (2009), Middle and later Pleistocene hominins in Africa and Southwest Asia.

Some observers in the past [e.g. Woodward (1938) and Wells (1951)] have advocated affinities between KhoiSan cranial trends and the Singa calvaria, and the possible genealogical ties thereof; others, Alan G. Morris (2003) for example, contest such viewpoints, noting that...

Although the skull is difficult to date, the most recent attempts have suggested that it is older than 100 000 years (Grun & Stringer 1991) and has little to do with the direct ancestry of specific recent African populations. - A. G. Morris (2003), The Myth of the East African 'Bushmen'.

As far as Morris is concerned, KhoiSan morphological trends are just as "derived" relatively recently in biohistory as any other recent group...

"The ancestral allelic states identified f rom both mitochondrial and Y-chromosome DNA do indeed reflect ancient roots but the total morphological pattern is as derived from the ancestral form as it is in any other human group. The morphology of populations reflects adaptive patterns that are dynamic responses to sequences of adaptive events in the local environment."

Taramsa-1 specimen ~ 55,000 years BP
A child burial was found at Taramsa-1 dating to this time (c.55,000BP): “The poorly preserved bones were those of a sub-adult ‘anatomically modern human’ similar in appearance to the Mechtoid populations of the north African Epipalaeolithic. The position of the body, as well as the depth of the pit in which it was found . . . suggest that the child had not died in this location but had been deliberately brought here to be buried” (Midant-Reynes 1992/2000 p.37).

Nazlet Khater specimen ~ 30,000 to 38,000 years BP

Wadi Kubanniya specimen ~ 20,000 years BP

Tushka specimens ~ 14,500 +/- 490 years BP [Wendorf 1968, and personal communication per Groves 1999]

Sahaba specimens ~ 13,700 +/- 600 years BP [Wendorf 1968, and personal communication per Groves 1999]

Jebel Sahaba-Wadi Halfa specimens ~ 12,000-6000 years BP [Sahaba specimens ~ 13,700 +/- 300 Wendorf 1968, per Groves 1999]

West Africa:

Jebel Irhoud specimens ~ 160,000/+ years ago, comprising of two adult male skulls (Irhoud 1 and 2) and juvenile's jaw (Irhoud 3) fragment, humerus (Irhoud 4) bone and a pelvis fragment (Irhoud 5)...

Above, we have a sketch of an adult male, and right by that, is the photo of the actual skull. In the image following, is the mandible fragment of a child, along with two subsequent images zeroing in on a tooth from the same specimeni.e."tooth and tooth growth lines of 160,000-year old Homo sapiens child" [courtesy of Natural History Museum].

Irhoud 1 and 2 adult male specimens were uncovered in 1961. Both reportedly have a mix of pleisiomorphic [such as low vault, thick supra-orbital ridges, occipital buns and robusticity] and "modern" traits [such as for example, the level of protrusion of the face and large rectangular orbits]. The same applies to the mandible fragment of what is estimated to be an eight-year old child (Irhoud 3), uncovered in 1968; it is deemed to be considerably robust and its posterior symphysis recalls the "archaic" types of Skhul or Qafzeh. The humerus bone (Irhoud 4)also deemed to that of a child, and uncovered in 1969continues the empirical trend of robusticity. Last but not least, "a fragmentary pelvis encased in breccia" was uncovered at the Jebel Irhoud site, as noted by Stringer and Gamble (1993). Courtesy of Natural History Museum, we are told the following about the mandible piece of an eight-year old child... 

"Tests on remains from a child show it was growing as slowly as an eight-year-old child would today. This is the earliest evidence of a prolonged childhood in our modern human ancestors, Homo sapiens."

"The team of scientists ... looked for molar teeth in the jaw that may not have erupted, an important clue to the development of a child. And a powerful X-ray technique on a fossilised tooth revealed microscopic growth lines hidden inside. This shows the tooth was immature and had grown slowly, the same as an eight-year-old child's would today." 

"Humans have the longest childhood of all primates, and this feature in nature is associated with complex social structures, as the brain has longer to develop during childhood.

More ancient human ancestors grew up much faster. For example Australopithecines , living about 3 million years ago, may have reached adulthood by the age of 12."

"The fossil remains of this child, who was about eight years old, were discovered in the Jebel Irhoud site in Morocco in 1968. 'This is a very important site and has often been neglected in the discussions of modern human origins,' says Chris. 'In my own case, studies of an adult skull from this site over 30 years ago was one of the factors that led me to the view that our species had evolved in Africa.'

'While I think that the Irhoud material is probably less 'modern' overall than do the authors of this paper, nevertheless these fossils could certainly represent populations ancestral to modern humans, and they show that North Africa may well have played a significant part in our origins,' concludes Chris." -
Courtesy of Natural History Museum 

These specimens had been prematurely dismissed as "Neanderthaloids" or "Neanderthal-like", but more recent research have shown that these specimens actually belonged to anatomically modern humans, albeit retaining what some call "pleisiomorphic" cranio-facial tidbits here and there. Furthermore, reactionary attempts to render these specimens as "non-African" fall flat, as they date to time frames earlier than the oldest known examples in both Europe [Upper Paleolithic ~ 30 to 35ky ago] and the so-called "Southwest Asia" [in the Levant ~ 100,000; see Qafzeh above].

Aterian specimens ~ dates ranging from 32,150 +/- 4800 years ago to 41,160 +/- 3500 years ago according to thermoluminesence estimation of an Aterian level wherein a mandible fragment and a piece of canine tooth were recovered; no radiometric age estimation is available for the Dar es-Soltane and Temara specimens at the moment according to E. Trinkaus (2005), who goes onto note that age estimations of Aterian levels, as put forth by Debenath (1994) and Wengler (1997), open up the possibility that the Aterian industry extended well into the late Paleolithic after 30,000 years BP, likely alluding to estimations such as that based off of a radiocarbon date on a "Helix" shellca. 25,580 +/- 130 years ago (Debenath 2000). These age estimates seem to point the stratigraphically upper layers of the Aterian industry, i.e. the latter layers (the Upper Paleolithic), since the complex extends to as far as the middle Paleolithic ~ 90,000 + years ago based on age estimates of the deeper or older layers of the industry.

The Aterian specimens all in all comprise of a partial skull, with the face sans a complete mandiblesave for a hemi-mandible, as shown in the image aboveto the left, a juvenile skull cap, as shown aboveto the right, an adolescent mandible fragment missing the ramus, yet another mandible fragment, and a canine tooth. The first specimens were recovered from the Dar es-Soltane II site in 1975, while the remaining two specimens were recovered from the El Harhoura site in 1977. The aforementioned Aterian "partial skull" (Dar es-Soltane 5) noticeably sports supra-orbital ridges, which some observers may well consider as part of the "pleisiomorphic" elements that accompany the "modern" characteristics; Erik Trinkaus describes the Dar es-Soltane 5 and Temara 1 specimens as follows...

"At about the same time period as the Nazlet Khater remains are the Aterian fossils from Dar-es-Soltane and Temara (Vallois & Roche 1958;Ferembach 1976, 1998;M´enard 1998, 2002). They have dentitions that are reduced relative to the preceding late Middle Pleistocene remains of the region (Hublin & Tillier 1981) but are still moderately large. Temara 2 lacks a supraorbital torus and has a rounded occipital region, and Dar-es-Soltane 5 has some prominence of the tuber symphyseos, reduction of the nasal region, distinct canine fossae, and a high and rounded anterior neurocranium.Yet, Temara 1 lacks a chin, and Dar-es-Soltane 5 has a clear supraorbital torus and a relatively wide mandibular ramus. For their late OIS 3 age, they exhibit an archaic/modern morphological mosaic unusual in Africa." - E. Trinkaus (2005), Early Modern Humans.

Taforalt specimens ~ 10,800 +/- 241 years BP to 12,070 +/- 400 years BP. [Roche 1963, dates per Groves 1999]

Afalou-bou-Rhummel specimens ~ date back to about the same time frame as the Taforalt specimens, although are proclaimed to be "*somewhat* later in date". [no specific dates provided by Groves 1999] 

Mechta-el-Arbi specimens ~ 8,500 years ago. [dates per Groves 1999] 

Gobero Early Holocene (Kiffian) specimens, Niger ~  9,500 to 10,000 years ago

In relation to the Gobero Kiffian remains, Sereno et al. (2008) note...

"Phase 2 peoples are tall in stature, approaching two meters for both males and females. Hyperflexed, supine burial postures predominate, their compact configuration and anatomical articulation suggesting that their bodies were tightly bound with animal skin, ligament or basketry binding, although no trace of these perishable materials are preserved (Figure 4C). Their crania are long and low and are characterized by a distinct occipital bun, flattened sagittal profile, pentagonal posterior outline, broad proportions across the zygoma and interorbital region, broad nasal aperture, and negligible alveolar prognathism (Figure 4D), features that are apparent in juveniles as young as four years of age (Figure 4E) and absent in skulls from mid-Holocene burials [see below, the specifics of the mid-Holocene Gobero specimens]" - Sereno et al. (2008), Lakeside Cemeteries in the Sahara: 5000 Years of Holocene Population and Environmental Change.

Hassi el-Abiod specimens, so-called "Mechtoids" or "Mechta-Afalou" of Mali ~ 4,500 to 7,000 years BP, comprising some 89 individuals according to some sources [see below for details]; 15 individuals were dated at ca. 7,000 years BP, while 46 specimens were dated at ca. 4,500 years BP [B.M. & C. Rothschild, 1996]

Barbara Barich notes about the Hassi el-Abiod burial patterns, that...

"The Hassi el Abiod cemetery in Mali, with its sample of 89 individuals, can be considered a real exception (Petit-Maire, Riser eds. 1983). This human group has been accurately studied and described, and clear inhumation practices have been identified. For example, they maintained a practice of placing the body in a crouched position, on the left or right side, with the head oriented towards the east (Dutour 1989). This also represents a very important anthropological sample, providing an invaluable opportunity for comparison with material from another important cemetery, Jebel Sahaba." - Barbara E. Barich, People, water, and grain: the beginnings of domestication in the Sahara and the Nile Valley, 1998.

Notice how what is ordinarily called "sub-Saharan west Africa" in Eurocentric media circles, is interestingly referred to as the "Sahara" when it comes to discussing certain matter, like in this case, the so-called "Mechtoids" of Hassi el-Abiod, or say, the Tamasheq ("Tuaregs") groups of that same region. In all other occasions, Mali is simply bunched along with, and dismissed as "sub-Saharan" Africa. Barich goes onto provide a schematic of Jebel Sahaba burial practice (below), and therein too, the head of the dead face east, while the bodies are placed in a crouched position, though mostly on their left side.

Asselar specimen from Asselar, Mali ~ 6,400 BP [C.A. Diop, per Chamla (1986), and Boule & Vallos (1932)]

Gobero Mid-Holocene (Tenerean) specimens, Niger ~ 4,800 to 6,700 years ago

"Occupational Interruption (6200–5200 B.C.E)

A harsh arid interval separates early and mid-Holocene populations at Gobero, when the paleolake appears to have dried out and the area abandoned. Although we have no means to directly assess aridity, no terrestrial or aquatic vertebrates or lakebed sediment have been dated to this interval, which lasted approximately one millennium (Figure 3). The only specimens dated within this interval were found in the paleolake deposit and consist of a cluster of the small gastropod Melanoides tuberculata, a species that prefers periodically flooded habitats to permanent water bodies." - Sereno et al. (2008), Lakeside Cemeteries in the Sahara: 5000 Years of Holocene Population and Environmental Change.

The Gobero Tenerean burials surface after this "occupational interruption", and as far as their cranio-morphological particulars go, Sereno et al. tell the reader that...

"Phase 3 humans have more gracile skeletons and shorter stature for both males and females. They are buried most commonly in semi-flexed postures on either left or right sides (Figure 5D, E). Their crania are long, high and narrow, and their faces are taller with considerable alveolar prognathism (Figure 5C). Principal components analysis of craniometric data clearly distinguishes the mid-Holocene population at Gobero (Gob-m) from all other sampled populations, including the early Holocene population at Gobero, Iberomaurusian and Capsian populations from the Maghreb, “Mechtoids” from Mali and Mauritania, as well as much older Aterian samples (Figure 6). The morphological isolation of the mid-Holocene population from Gobero is particularly noteworthy, as several of the other populations sampled (WMC, Mali, Maur) are believed to be mid-Holocene contemporaries." - Sereno et al. (2008), Lakeside Cemeteries in the Sahara: 5000 Years of Holocene Population and Environmental Change.

Haua Fteah mandible specimens ~ 40,000 to 46,000 years ago. These comprise of two ramus fragments attributed to two individuals [Haua Fteah I and 2], between 18 & 25 years of age and between 12 and 17 years of age respectively. Haua Fteah 1 was uncovered in 1952, while Haua Fteah 2 was uncovered in 1955. As with other northwest specimens described above, and northeastern African specimens, these specimens were in the past assumed to belong to "Neanderthal-like" populations, until more recent assessments demonstrated similarities to recent groups, including "sub-Saharan" Africans.

*Click on small-sized images for higher resolution. More to come, as this page gets updated.

Additional reading:

Mechta and Afalou: Do they and the so-called "Mechtoids" constitute a type with the "Cro-Magnon"?