  Site Location in Chad | |
| Location | Borkou-Ennedi-Tibesti Region, Chad |
|---|---|
| Region | North-Central Africa |
| Coordinates | 17°40′01″N17°19′59″E / 17.667°N 17.333°E |
| Type | Archaeological |
| Site notes | |
| Excavation dates | 1961 |
| Archaeologists | Yves Coppens |
Yaho or Yayo [1] is an archeological site 160 kilometers northwest of Koro Toro, Chad. In 1961, Yves Coppens excavated a partial hominin face and erected the taxon Tchadanthropus uxoris. [2] Loxodonta atlantica were also discovered from the site. [3]
It is proposed that the middle of the Angamma delta bore Holocene strata dating to 1000 years in the lowest parts and up to 7300 years at the latest. Other parts of the formation reach up to 10,000 years. [4]
The Angamma Delta is found within the area north of paleolake Megachad. The delta is very well preserved, standing up to 330m tall, as it can be observed sloping into a mudstone and diatomite-filled basin that drops 240m. The delta was fed by a braided fluvial distributary leading from the Tibesti Mountains from the north. They do not cut through the delta, suggesting that the braided rivers dried before the lake did. Delta sediment was visibly disturbed by waves from the lake, and the front was eroded, revealing other sediments within. [4]
Its sediments are very exposed through a series of cliffs and canyons that run perpendicular from the delta. Underneath the delta are volcanic tuffs and breccias overlain with diatomite. The sediment is composed of silts and fine sand interspersed with thin intraformational conglomerates. Strata thicken nearer to the top and have distinct boundaries. It shows evidence of river flooding events that supplied sediment to the delta. [4]
On March 16, 1961, Yves Coppens' wife, Françoise Le Guennec, [5] discovered a hominin fossil at one end of the Angamma cliff, 11 kilometers from the western well of Yayo. Initially, the specimen was assumed to be an australopithecine, but Coppens would later assign it the temporary name Tchadanthropus uxoris [6] based on the country and lake of origin and honoring Le Guennec. The hominin fossil was found in deposits that were also populated with fossils of the proboscid Loxodonta atlantica , which Coppens suggested might place the hominin within the late Lower or early Middle Pleistocene. [3]
In 1965, Marcel Bleustein organized a conference for the discovery, which scientists were very skeptical of. The press, however, were more interested in the implications of the discovery. [7] The discovery of this fossil made Coppens media famous. [8] Tobias (1973) stated that the fossil was likely to be Homo erectus and less than one million years old. [9] In 2010, the specimen was given an updated age estimate of 900-700 kya. [10] According to data proposed by Servant (1983), the specimen may be only 10 ka based on the geology of the site. [11]
The specimen may be a young individual based on the presence of a metopic suture, but this feature was also present in the adult [12] Zhoukoudian XII, so it may be a feature present regardless of age. The face is broad and short, but due to erosion of the upper jaw, its entire height cannot be calculated. The vault is high and intermediate in curvature between Zhoukoudian, Chellean Man, and Australopithecus . Another possible testament to age is slight postorbital constriction. However, the frontal sinus is expanded, indicative of adulthood. The tori are heavier than those of australopiths, but lighter than later hominins. The frontal process bears a posterior obliquity that might signify a high zygomatic root. The sockets are large and rectangular like those of Kabwe. There is substantial prognathism below the nose; however, Wood (2002) notes that this apparent prognathism may be a product of warping caused by winds that inadvertently gave the skull an australopithecine-like appearance, which would support Servant (1983)'s hypothesis that the specimen is only 10 ka old. [13] [11] No teeth were preserved, but the incisor socket suggests that the teeth were small, with no diastema. The nasal anatomy is similar to that of Solo. [3] The brain capacity is difficult to calculate, but it may have been on the smaller end. [14]
Originally, Coppens provisionally correlated the fossil as an australopithecine. In 1966, he suggested that the face bore similarities with early and later hominins, thinking that it either represented a late australopithecine or, more likely in his opinion, an early "pithecanthropine". He also considered attribution to Homo habilis , which was a recent advancement at the time. [6] He assigned the provisional name Tchadanthropus uxoris to the find as a placeholder until greater understanding of human evolution could allow for taxonomic simplification. [3] In 2017, Coppens admitted in an interview that the fossil was closer to H. erectus than an australopithecine. [7] A less popular scientific name for the specimen is Homo uxoris. [10] Most regard the specimen as a member of H. habilis or H. erectus. [15] [16]
| Species | Locality | Notes | References |
|---|---|---|---|
| Heterocypris giesbrechtii | CH38 | Abundant, all life stages | [4] |
| Sarscypridopsis aculeata | One specimen | ||
| Sarscypridopsis cf. bicornis | CH39 | ||
| Darwinula stevensoni | Moderately abundant | ||
| Cytheridella cf. tepida |
| Species | Locality | Notes | References |
|---|---|---|---|
| "Two gastropod species" | CHG59 | [4] | |
| Coelatura aegyptiaca | CHG59, CH60 | Bivalve | |
| Pisidium sp. | |||
| Valvata sp. |
| Species | Locality | Notes | References |
|---|---|---|---|
| Candona cf. neglecta | Possibly a new species of crustacean | [4] | |
| Limnocythere inopinata | CH60 | Moderately abundant crustacean |
| Species | Locality | Notes | References |
|---|---|---|---|
| Homo erectus | 11km west of the Angamma cliff | One hominin face discovered by Françoise Le Guennec, [5] wife of Yves Coppens and variously attributed to various species of hominin. Its true placement is unknown. | [3] |
| Homo habilis | |||
| Homo uxoris | |||
| Tchadanthropus uxoris | |||
| Loxodonta africana [4] | |||
| Loxodonta atlantica | An elephant found in association with hominin remains | ||
| "hippopotamus" | "A small form," no genus mentioned |
Homo habilis is an extinct species of archaic human from the Early Pleistocene of East and South Africa about 2.3 million years ago to 1.65 million years ago (mya). Upon species description in 1964, H. habilis was highly contested, with many researchers recommending it be synonymised with Australopithecus africanus, the only other early hominin known at the time, but H. habilis received more recognition as time went on and more relevant discoveries were made. By the 1980s, H. habilis was proposed to have been a human ancestor, directly evolving into Homo erectus, which directly led to modern humans. This viewpoint is now debated. Several specimens with insecure species identification were assigned to H. habilis, leading to arguments for splitting, namely into "H. rudolfensis" and "H. gautengensis" of which only the former has received wide support.
Kenyanthropus is a genus of extinct hominin identified from the Lomekwi site by Lake Turkana, Kenya, dated to 3.3 to 3.2 million years ago during the Middle Pliocene. It contains one species, K. platyops, but may also include the 2 million year old Homo rudolfensis, or K. rudolfensis. Before its naming in 2001, Australopithecus afarensis was widely regarded as the only australopithecine to exist during the Middle Pliocene, but Kenyanthropus evinces a greater diversity than once acknowledged. Kenyanthropus is most recognisable by an unusually flat face and small teeth for such an early hominin, with values on the extremes or beyond the range of variation for australopithecines in regard to these features. Multiple australopithecine species may have coexisted by foraging for different food items, which may be reason why these apes anatomically differ in features related to chewing.
Orrorin is an extinct genus of primate within Homininae from the Miocene Lukeino Formation and Pliocene Mabaget Formation, both of Kenya.
Australopithecus (, OS-trə-lə-PITH-i-kəs, -loh-; or is a genus of early hominins that existed in Africa during the Pliocene and Early Pleistocene. The genera Homo, Paranthropus, and Kenyanthropus evolved from some Australopithecus species. Australopithecus is a member of the subtribe Australopithecina, which sometimes also includes Ardipithecus, though the term "australopithecine" is sometimes used to refer only to members of Australopithecus. Species include A. garhi, A. africanus, A. sediba, A. afarensis, A. anamensis, A. bahrelghazali, and A. deyiremeda. Debate exists as to whether some Australopithecus species should be reclassified into new genera, or if Paranthropus and Kenyanthropus are synonymous with Australopithecus, in part because of the taxonomic inconsistency.
Homo ergaster is an extinct species or subspecies of archaic humans who lived in Africa in the Early Pleistocene. Whether H. ergaster constitutes a species of its own or should be subsumed into H. erectus is an ongoing and unresolved dispute within palaeoanthropology. Proponents of synonymisation typically designate H. ergaster as "African Homo erectus" or "Homo erectus ergaster". The name Homo ergaster roughly translates to "working man", a reference to the more advanced tools used by the species in comparison to those of their ancestors. The fossil range of H. ergaster mainly covers the period of 1.7 to 1.4 million years ago, though a broader time range is possible. Though fossils are known from across East and Southern Africa, most H. ergaster fossils have been found along the shores of Lake Turkana in Kenya. There are later African fossils, some younger than 1 million years ago, that indicate long-term anatomical continuity, though it is unclear if they can be formally regarded as H. ergaster specimens. As a chronospecies, H. ergaster may have persisted to as late as 600,000 years ago, when new lineages of Homo arose in Africa.
Homo rudolfensis is an extinct species of archaic human from the Early Pleistocene of East Africa about 2 million years ago (mya). Because H. rudolfensis coexisted with several other hominins, it is debated what specimens can be confidently assigned to this species beyond the lectotype skull KNM-ER 1470 and other partial skull aspects. No bodily remains are definitively assigned to H. rudolfensis. Consequently, both its generic classification and validity are debated without any wide consensus, with some recommending the species to actually belong to the genus Australopithecus as A. rudolfensis or Kenyanthropus as K. rudolfensis, or that it is synonymous with the contemporaneous and anatomically similar H. habilis.
The Olduvai Gorge or Oldupai Gorge in Tanzania is one of the most important paleoanthropological localities in the world; the many sites exposed by the gorge have proven invaluable in furthering understanding of early human evolution. A steep-sided ravine in the Great Rift Valley that stretches across East Africa, it is about 48 km long, and is located in the eastern Serengeti Plains within the Ngorongoro Conservation Area in the Olbalbal ward located in Ngorongoro District of Arusha Region, about 45 kilometres from Laetoli, another important archaeological locality of early human occupation. The British/Kenyan paleoanthropologist-archeologist team of Mary and Louis Leakey established excavation and research programs at Olduvai Gorge that achieved great advances in human knowledge. The site is registered as one of the National Historic Sites of Tanzania.
Meganthropus is an extinct genus of non-hominin hominid ape, known from the Pleistocene of Indonesia. It is known from a series of large jaw and skull fragments found at the Sangiran site near Surakarta in Central Java, Indonesia, alongside several isolated teeth. The genus has a long and convoluted taxonomic history. The original fossils were ascribed to a new species, Meganthropus palaeojavanicus, and for a long time was considered invalid, with the genus name being used as an informal name for the fossils.
Homo is a genus of great ape that emerged from the genus Australopithecus and encompasses only a single extant species, Homo sapiens, along with a number of extinct species classified as either ancestral or closely related to modern humans; these include Homo erectus and Homo neanderthalensis. The oldest member of the genus is Homo habilis, with records of just over 2 million years ago. Homo, together with the genus Paranthropus, is probably most closely related to the species Australopithecus africanus within Australopithecus. The closest living relatives of Homo are of the genus Pan, with the ancestors of Pan and Homo estimated to have diverged around 5.7-11 million years ago during the Late Miocene.
Paranthropus aethiopicus is an extinct species of robust australopithecine from the Late Pliocene to Early Pleistocene of East Africa about 2.7–2.3 million years ago. However, it is much debated whether or not Paranthropus is an invalid grouping and is synonymous with Australopithecus, so the species is also often classified as Australopithecus aethiopicus. Whatever the case, it is considered to have been the ancestor of the much more robust P. boisei. It is debated if P. aethiopicus should be subsumed under P. boisei, and the terms P. boisei sensu lato and P. boisei sensu stricto can be used to respectively include and exclude P. aethiopicus from P. boisei.
Australopithecus garhi is a species of australopithecine from the Bouri Formation in the Afar Region of Ethiopia 2.6–2.5 million years ago (mya) during the Early Pleistocene. The first remains were described in 1999 based on several skeletal elements uncovered in the three years preceding. A. garhi was originally considered to have been a direct ancestor to Homo and the human line, but is now thought to have been an offshoot. Like other australopithecines, A. garhi had a brain volume of 450 cc (27 cu in); a jaw which jutted out (prognathism); relatively large molars and premolars; adaptations for both walking on two legs (bipedalism) and grasping while climbing (arboreality); and it is possible that, though unclear if, males were larger than females. One individual, presumed female based on size, may have been 140 cm tall.
Paranthropus boisei is a species of australopithecine from the Early Pleistocene of East Africa about 2.5 to 1.15 million years ago. The holotype specimen, OH 5, was discovered by palaeoanthropologist Mary Leakey in 1959 at Olduvai Gorge, Tanzania and described by her husband Louis a month later. It was originally placed into its own genus as "Zinjanthropus boisei", but is now relegated to Paranthropus along with other robust australopithecines. However, it is also argued that Paranthropus is an invalid grouping and synonymous with Australopithecus, so the species is also often classified as Australopithecus boisei.
Human taxonomy is the classification of the human species within zoological taxonomy. The systematic genus, Homo, is designed to include both anatomically modern humans and extinct varieties of archaic humans. Current humans have been designated as subspecies Homo sapiens sapiens, differentiated, according to some, from the direct ancestor, Homo sapiens idaltu.
Australopithecus bahrelghazali is an extinct species of australopithecine discovered in 1995 at Koro Toro, Bahr el Gazel, Chad, existing around 3.5 million years ago in the Pliocene. It is the first and only australopithecine known from Central Africa, and demonstrates that this group was widely distributed across Africa as opposed to being restricted to East and southern Africa as previously thought. The validity of A. bahrelghazali has not been widely accepted, in favour of classifying the specimens as A. afarensis, a better known Pliocene australopithecine from East Africa, because of the anatomical similarity and the fact that A. bahrelghazali is known only from 3 partial jawbones and an isolated premolar. The specimens inhabited a lakeside grassland environment with sparse tree cover, possibly similar to the modern Okavango Delta, and similarly predominantly ate C4 savanna foods—such as grasses, sedges, storage organs, or rhizomes—and to a lesser degree also C3 forest foods—such as fruits, flowers, pods, or insects. However, the teeth seem ill-equipped to process C4 plants, so its true diet is unclear.
In physical anthropology, post-orbital constriction is the narrowing of the cranium (skull) just behind the eye sockets found in most non-human primates and early hominins. This constriction is very noticeable in non-human primates, slightly less so in Australopithecines, even less in Homo erectus and completely disappears in modern Homo sapiens. Post-orbital constriction index in non-human primates and hominin range in category from increased constriction, intermediate, reduced constriction and disappearance. The post-orbital constriction index is defined by either a ratio of minimum frontal breadth (MFB), behind the supraorbital torus, divided by the maximum upper facial breadth (BFM), bifrontomalare temporale, or as the maximum width behind the orbit of the skull.
Homo erectus is an extinct species of archaic human from the Pleistocene, with its earliest occurrence about 2 million years ago. Its specimens are among the first recognizable members of the genus Homo.
Australopithecus sediba is an extinct species of australopithecine recovered from Malapa Cave, Cradle of Humankind, South Africa. It is known from a partial juvenile skeleton, the holotype MH1, and a partial adult female skeleton, the paratype MH2. They date to about 1.98 million years ago in the Early Pleistocene, and coexisted with Paranthropus robustus and Homo ergaster / Homo erectus. Malapa Cave may have been a natural death trap, the base of a long vertical shaft which creatures could accidentally fall into. A. sediba was initially described as being a potential human ancestor, and perhaps the progenitor of Homo, but this is contested and it could also represent a late-surviving population or sister species of A. africanus which had earlier inhabited the area.
SK 847 is the abbreviated designation for the fossilized fragments of a Homo habilis cranium, discovered in South Africa, which was dated to an age between 1.8 and 1.5 million years. This fossil shares morphological traits with the early African Homo erectus, sometimes known as Homo ergaster.
Changes to the dental morphology and jaw are major elements of hominid evolution. These changes were driven by the types and processing of food eaten. The evolution of the jaw is thought to have facilitated encephalization, speech, and the formation of the uniquely human chin.
The Dmanisi hominins, Dmanisi people, or Dmanisi man were a population of Early Pleistocene hominins whose fossils have been recovered at Dmanisi, Georgia. The fossils and stone tools recovered at Dmanisi range in age from 1.85 to 1.77 million years old, making the Dmanisi hominins the earliest well-dated hominin fossils in Eurasia and the best preserved fossils of early Homo from a single site so early in time, though earlier fossils and artifacts have been found in Asia. Though their precise classification is controversial and disputed, the Dmanisi fossils are highly significant within research on early hominin migrations out of Africa. The Dmanisi hominins are known from over a hundred postcranial fossils and five famous well-preserved skulls, referred to as Dmanisi Skulls 1–5.