Homo rudolfensis

Last updated

Homo rudolfensis
Temporal range: Pleistocene, 2.5/1.9–1.85/1.55  Ma
O
S
D
C
P
T
J
K
Pg
N
KNM ER 1470 (H. rudolfensis).png
Reconstruction of the KNM-ER 1470 skull
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primates
Suborder: Haplorhini
Infraorder: Simiiformes
Family: Hominidae
Subfamily: Homininae
Tribe: Hominini
Genus: Homo (?)
Species:
H. rudolfensis
Binomial name
Homo rudolfensis
(Alekseyev, 1986)
Synonyms

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 .

Contents

H. rudolfensis is distinguished from H. habilis by larger size, but it is also argued that this species actually consists of male H. habilis specimens, assuming that H. habilis was sexually dimorphic and males were much larger than females. Because no bodily remains are definitely identified, body size estimates are largely based on the stature of H. habilis. Using this, male H. rudolfensis may have averaged about 160 cm (5 ft 3 in) in height and 60 kg (130 lb) in weight, and females 150 cm (4 ft 11 in) and 51 kg (112 lb). KNM-ER 1470 had a brain volume of about 750 cc (46 cu in). Like other early Homo, H. rudolfensis had large cheek teeth and thick enamel.

Early Homo species exhibit marked brain growth compared to Australopithecus predecessors, which is typically explained as a change in diet with a calorie-rich food source, namely meat. Though not associated with tools, dental anatomy suggests some processing of plant or meat fiber before consumption, though the mouth could still effectively chew through mechanically challenging food, indicating tool use did not greatly affect diet.

Research history

Reconstruction of H. rudolfensis by Mauricio Anton Homo rudolfensis.png
Reconstruction of H. rudolfensis by Mauricio Antón

The first fossils were discovered in 1972 along Lake Turkana (at the time called Lake Rudolf) in Kenya, and were detailed by Kenyan palaeoanthropologist Richard Leakey the following year. The specimens were: a large and nearly complete skull (KNM-ER 1470, the lectotype) discovered by Bernard Ngeneo, a local; a right femur (KNM-ER 1472) discovered by J. Harris; an upper femur (proximal) fragment (KNM-ER 1475) discovered by fossil collector Kamoya Kimeu; and a complete left femur (KNM-ER 1481) discovered by Harris. However, it is unclear if the femora belong to the same species as the skull. Leakey classified them under the genus Homo because he had reconstructed the skull fragments so that it had a large brain volume and a flat face, but did not assign them to a species. Because the horizon they were discovered in was, at the time, dated to 2.9–2.6 million years ago (mya), Leakey thought these specimens were a very early human ancestor. [1] This challenged the major model of human evolution at the time where Australopithecus africanus gave rise to Homo about 2.5 mya, but if Homo had already existed at this time, it would call for serious revisions. [2] However, the area was redated to about 2 mya in 1977 (the same time period as H. habilis and H. ergaster / H. erectus ), [3] and more precisely to 2.1–1.95 mya in 2012. [4] They were first assigned to the species habilis in 1975 by anthropologists Colin Groves and Vratislav Mazák. In 1978, in a joint paper with Leakey and English anthropologist Alan Walker, Walker suggested the remains belong in Australopithecus (and that the skull was incorrectly reconstructed), but Leakey still believed they belonged to Homo, though they both agreed that the remains could belong to habilis. [5]

KNM-ER 1470 was much larger than the Olduvai remains, so the terms H. habilis sensu lato ("in the broad sense") and H. habilis sensu stricto ("in the strict sense") were used to include or exclude the larger morph, respectively. [6] [7] In 1986, English palaeoanthropologist Bernard Wood first suggested these remains represent a different Homo species, which coexisted with H. habilis and H. ergaster/H. erectus. Coexisting Homo species conflicted with the predominant model of human evolution at the time which was that modern humans evolved in a straight line directly from H. ergaster/H. erectus which evolved directly from H. habilis. [8] In 1986, the remains were placed into a new species, rudolfensis, by Russian anthropologist Valery Alekseyev [9] (but he used the genus Pithecanthropus , which was changed to Homo three years later by Groves). [10] In 1999, Kennedy argued that the name was invalid because Alekseyev had not assigned a holotype. [11] Pointing out that this is in fact not mandatory, Wood the same year nevertheless designated KNM-ER 1470 as the lectotype. [12] However, the validity of this species has also been debated on material grounds, with some arguing that H. habilis was highly sexually dimorphic like modern non-human apes, with the larger skulls classified as "H. rudolfensis" actually representing male H. habilis. [7] [12] In 1999, Wood and biological anthropologist Mark Collard recommended moving rudolfensis and habilis to Australopithecus based on the similarity of dental adaptations. However, they conceded that dental anatomy is highly variable among hominins and not always reliable when formulating family trees. [13]

KNM-ER 1802 Homo rudolfensis KNM-ER 1802 IMG 5634 BMNH.jpg
KNM-ER 1802

In 2003, Australian anthropologist David Cameron concluded that the earlier australopithecine Kenyanthropus platyops was the ancestor of rudolfensis, and reclassified it as K. rudolfensis. He also believed that Kenyanthropus was more closely related to Paranthropus than Homo. [14] In 2008, a re-reconstruction of the skull concluded it was incorrectly restored originally, though agreed with the classification as H. rudolfensis. [15] In 2012, British palaeoanthropologist Meave Leakey described the juvenile partial face KNM-ER 62000 discovered in Koobi Fora, Kenya; noting it shares several similarities to KNM-ER 1470 and is smaller, she assigned it to H. rudolfensis, and, because prepubescent male and female bones should be indistinguishable, differences between juvenile H. rudolfensis and adult H. habilis specimens support species distinction. She also concluded that the jawbone KNM-ER 1802, an important specimen often used in classifying other specimens as H. rudolfensis, actually belongs to a different (possibly undescribed) species, [16] but American palaeoanthropologist Tim D. White believes this to be premature because it is unclear how wide the range of variation is in early hominins. [6] The 2013 discovery of the 1.8 Ma Georgian Dmanisi skulls which exhibit several similarities with early Homo have led to suggestions that all contemporary groups of early Homo in Africa, including H. habilis and H. rudolfensis, are the same species and should be assigned to H. erectus. [17] [18] There is still no wide consensus on how rudolfensis and habilis relate to H. ergaster and descendent species. [19]

Beyond KNM-ER 1470, there is disagreement on which specimens actually belong in H. rudolfensis as it is difficult to assign with accuracy remains that do not preserve the face and jaw. [6] [7] No H. rudolfensis bodily elements have been definitively associated with a skull and thus to the species. [20] Most proposed H. rudolfensis fossils come from Koobi Fora and date to 1.9–1.85 mya. Remains from the Shungura Formation, Ethiopia, and Uraha, Malawi, are dated as far back as 2.5–2.4 mya, which would make it the earliest identified species of Homo. The latest potential specimen is KNM-ER 819 dating to 1.65–1.55 mya. [20] :210

H. habilis

H. rudolfensis

H. ergaster

H. erectus

H. antecessor

H. heidelbergensis

H. neanderthalensis

H. sapiens

Homo family tree showing H. rudolfensis and H. habilis at the base as offshoots of the human line [21]

Nonetheless, H. rudolfensis and H. habilis generally are recognised members of the genus at the base of the family tree, with arguments for synonymisation or removal from the genus not widely adopted. [22] Though it is now largely agreed upon that Homo evolved from Australopithecus, the timing and placement of this split has been much debated, with many Australopithecus species having been proposed as the ancestor. The discovery of LD 350-1, the oldest Homo specimen, dating to 2.8 mya, in the Afar Region of Ethiopia may indicate that the genus evolved from A. afarensis around this time. The species LD 350-1 belongs to could be the ancestor of H. rudolfensis and H. habilis, but this is unclear. [23] Based on 2.1 million year old stone tools from Shangchen, China, possibly an ancestral species to H. rudolfensis and H. habilis dispersed across Asia. [24]

Anatomy

KNM-ER 1470 H. rudolfensis (left) vs KNM-ER 1813 H. habilis (right) Homo rudolfensis (KNM-ER 1470 cast) and Homo habilis (KNM-ER 1813 cast) at Goteborgs Naturhistoriska Museum 8595.jpg
KNM-ER 1470 H. rudolfensis (left) vs KNM-ER 1813 H. habilis (right)

Skull

In 1973, Mr. Leakey had reconstructed the skull KNM-ER 1470 with a flat face and a brain volume of 800 cc (49 cu in). [1] In 1983, American physical anthropologist Ralph Holloway revised the base of the skull and calculated a brain volume of 752–753 cc (45.9–46.0 cu in). [25] For comparison, H. habilis specimens average about 600 cc (37 cu in), and H. ergaster850 cc (52 cu in). [26] Anthropologist Timothy Bromage and colleagues revised the face again at a 5° incline (slightly prognathic) instead of completely flat, but pushed the nasal bone back directly beneath the frontal bones. He then said it was possible to predict brain size based on just the face and (disregarding the braincase) calculated 526 cc (32.1 cu in), and chalked up the errors of Leakey's reconstruction to a lack of research of the biological principles of facial anatomy at the time as well as confirmation bias, as a flat-faced reconstruction of the skull aligned with the predominant model of human evolution at the time. This was refuted by American palaeoanthropologist John D. Hawks because the skull remained more or less unchanged except for the 5° rotation outwards. [27] Bromage and colleagues returned in 2008 with a revised skull reconstruction and brain volume estimate of 700 cc (43 cu in). [15]

UR 501, the oldest H. rudolfensis specimen HPCR-UR 501-01.jpg
UR 501, the oldest H. rudolfensis specimen

Fossils have generally been classified into H. rudolfensis due to large skull size, flatter and broader face, broader cheek teeth, more complex tooth crowns and roots, and thicker enamel compared to H. habilis. [28] Early Homo are characterised by larger teeth compared to later Homo. The cheek teeth of KNM-ER 60000, a jawbone, in terms of size are on the lower end for early Homo, except for the third molar which is within range. The molars increase in size towards the back of the mouth. The tooth rows of KNM-ER 1470, KNM-ER 60000, and KNM-ER 62000 are rectangular, whereas the tooth row of KNM-ER 1802 is U-shaped, which may indicate that these two morphs represent different species, [16] or demonstrate the normal range of variation for H. rudolfensis jaws. [6] In UR 501 from Uraha, Malawi—the oldest H. rudolfensis specimen dating to 2.5–2.3 mya—the tooth enamel thickness is the same as in other early Homo, but the enamel on the molars is almost as thick as Paranthropus molars (which have some of the thickest enamel of any hominin). Such a wide variation in enamel thickness across the cheek teeth is not exhibited in KNM-ER 1802, which may indicate regional differences among H. rudolfensis populations. [28] [29]

Build

Body size estimates of H. rudolfensis and H. habilis typically conclude a small size comparable to australopithecines. These largely depend on the H. habilis partial skeleton OH 62 estimated at 100–120 cm (3 ft 3 in – 3 ft 11 in) in height and 20–37 kg (44–82 lb) in weight. H. rudolfensis is thought to be bigger than H. habilis, but it is unclear how big this species was as no bodily elements have been definitively associated with a skull. [30] Based on just the KNM-ER 1470 skull, male H. rudolfensis were estimated to have been 160 cm (5 ft 3 in) in height and 60 kg (130 lb) in weight, and females 150 cm (4 ft 11 in) and 51 kg (112 lb). [26]

For specimens that might be H. rudolfensis: the femur KNM-ER 1472 which may also be H. habilis or H. ergaster was estimated at 155.9 cm (5 ft 1 in) and 41.8 kg (92 lb), the humerus KNM-ER 1473 162.9 cm (5 ft 4 in) and 47.1 kg (104 lb), the partial leg KNM-ER 1481 which may also be H. ergaster156.7 cm (5 ft 2 in) and 41.8 kg (92 lb), the pelvis KNM-ER 3228 which may also be H. ergaster165.8 cm (5 ft 5 in) and 47.2 kg (104 lb), and the femur KNM-ER 3728 which may be H. habilis or P. boisei 153.3 cm (5 ft) and 40.3 kg (89 lb). [30] It is generally assumed that pre-H. ergaster hominins, including H. rudolfensis and H. habilis, exhibited sexual dimorphism with males markedly bigger than females. However, relative female body mass is unknown in either species. [20]

Early hominins, including H. rudolfensis, are thought to have had thick body hair coverage like modern non-human apes because they appear to have inhabited cooler regions and are thought to have had a less active lifestyle than (presumed hairless) post-ergaster species, and so probably required thick body hair to stay warm. [31] The juvenile specimen KNM-ER 62000, a partial face, has the same age landmarks as a 13 to 14 year old modern human, but more likely died at around 8 years of age due to the presumed faster growth rate among early hominins based on dental development rate. [16]

Culture

It is typically thought that the diets of early Homo had a greater proportion of meat than Australopithecus, and that this led to brain growth. The main hypotheses regarding this are: meat is energy- and nutrient-rich and put evolutionary pressure on developing enhanced cognitive skills to facilitate strategic scavenging and monopolise fresh carcasses, or meat allowed the large and calorie-expensive ape gut to decrease in size allowing this energy to be diverted to brain growth. Alternatively, it is also suggested that early Homo, in a drying climate with scarcer food options, relied primarily on underground storage organs (such as tubers) and food sharing, which facilitated social bonding among both male and female group members. However, unlike what is presumed for H. ergaster and later Homo, short-statured early Homo were likely incapable of endurance running and hunting, and the long and Australopithecus-like forearm of H. habilis could indicate early Homo were still arboreal to a degree. Also, organised hunting and gathering is thought to have emerged in H. ergaster. Nonetheless, the proposed food-gathering models to explain large brain growth necessitate increased daily travel distance. [32] Large incisor size in H. rudolfensis and H. habilis compared to Australopithecus predecessors implies these two species relied on incisors more. The large, Australopithecus-like molars could indicate more mechanically challenging food compared to later Homo. The bodies of the mandibles of H. rudolfensis and other early Homo are thicker than those of modern humans and all living apes, more comparable to Australopithecus. The mandibular body resists torsion from the bite force or chewing, meaning their jaws could produce unusually powerful stresses while eating. [20]

Reconstruction of KNM-ER 1470 skull and jaw KNM-ER 1470 with jaw.jpg
Reconstruction of KNM-ER 1470 skull and jaw

H. rudolfensis is not associated with any tools. However, the greater molar cusp relief in H. rudolfensis and H. habilis compared to Australopithecus suggests the former two used tools to fracture tough foods (such as pliable plant parts or meat), otherwise the cusps would have been more worn down. Nonetheless, the jaw adaptations for processing mechanically challenging food indicates technological advancement did not greatly affect their diet. Large concentrations of stone tools are known from Koobi Fora. Because these aggregations are coincident with the emergence of H. ergaster, it is probable H. ergaster manufactured them, though it is not possible to definitively attribute the tools to a species because H. rudolfensis, H. habilis, and P. boisei are also well known from the area. [20] The oldest specimen of Homo, LD 350-1, is associated with the Oldowan stone tool industry, meaning this tradition had been in use by the genus since near its emergence. [33]

Early H. rudolfensis and Paranthropus have exceptionally thick molars for hominins, and the emergence of these two coincides with a cooling and aridity trend in Africa about 2.5 mya. This could mean they evolved due to climate change. Nonetheless, in East Africa, tropical forests and woodlands still persisted through periods of drought. [28] H. rudolfensis coexisted with H. habilis, H. ergaster, and P. boisei. [20]

See also

Related Research Articles

<i>Homo habilis</i> Archaic human species from 2.1 to 1.5 mya

Homo habilis is an extinct species of archaic human from the Early Pleistocene of East and South Africa about 2.31 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.

<i>Kenyanthropus</i> Oldest-known tool-making hominin

Kenyanthropus is a hominin genus 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.

<i>Paranthropus</i> Contested extinct genus of hominins

Paranthropus is a genus of extinct hominin which contains two widely accepted species: P. robustus and P. boisei. However, the validity of Paranthropus is contested, and it is sometimes considered to be synonymous with Australopithecus. They are also referred to as the robust australopithecines. They lived between approximately 2.9 and 1.2 million years ago (mya) from the end of the Pliocene to the Middle Pleistocene.

<i>Homo ergaster</i> Extinct species or subspecies of archaic human

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.

<i>Homo</i> Genus of hominins that includes humans and their closest extinct relatives

Homo is the genus that emerged in the genus Australopithecus that encompasses the extant species Homo sapiens, along with several extinct species classified as either ancestral to or closely related to modern humans, including Homo erectus and Homo neanderthalensis. The oldest member of Homo is Homo habilis with records of just over 2 million years ago. Homo, together with the genus Paranthropus, is probably sister to Australopithecus africanus, which itself had previously split from the lineage of Pan, the chimpanzees.

Paleoanthropology or paleo-anthropology is a branch of paleontology and anthropology which seeks to understand the early development of anatomically modern humans, a process known as hominization, through the reconstruction of evolutionary kinship lines within the family Hominidae, working from biological evidence and cultural evidence.

<i>Paranthropus aethiopicus</i> Extinct species of hominin of East Africa

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.

<i>Australopithecus garhi</i> Extinct hominid from the Afar Region of Ethiopia 2.6–2.5 million years ago

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.

<i>Paranthropus robustus</i> Extinct species of hominin of South Africa

Paranthropus robustus is a species of robust australopithecine from the Early and possibly Middle Pleistocene of the Cradle of Humankind, South Africa, about 2.27 to 0.87 million years ago. It has been identified in Kromdraai, Swartkrans, Sterkfontein, Gondolin, Cooper's, and Drimolen Caves. Discovered in 1938, it was among the first early hominins described, and became the type species for the genus Paranthropus. However, it has been argued by some that Paranthropus is an invalid grouping and synonymous with Australopithecus, so the species is also often classified as Australopithecus robustus.

<i>Paranthropus boisei</i> Extinct species of hominin of East Africa

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, 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.

<span class="mw-page-title-main">Koobi Fora</span> Kenyan archeological site

Koobi Fora refers primarily to a region around Koobi Fora Ridge, located on the eastern shore of Lake Turkana in the territory of the nomadic Gabbra people. According to the National Museums of Kenya, the name comes from the Gabbra language:

In the language of the Gabbra people who live near the site, the term Koobi Fora means a place of the commiphora and the source of myrrh...

<span class="mw-page-title-main">KNM-ER 1813</span> Hominin fossil

KNM ER 1813 is a skull of the species Homo habilis. It was discovered in Koobi Fora, Kenya by Kamoya Kimeu in 1973, and is estimated to be 1.9 million years old.

<span class="mw-page-title-main">OH 24</span> Hominin fossil

OH 24 is a fossilized skull of the species Homo habilis. It was discovered in Olduvai Gorge, Tanzania by Peter Nzube in 1968. The skull was found crushed almost flat and was therefore named after the famously skinny model of the time Twiggy. Estimated at 1.8 mya, the cranium was found crushed flat and cemented together with a mass coating of limestone. It is now a Smithsonian exhibit item.

KNM ER 406 is an almost complete fossilized skull of the species Paranthropus boisei. It was discovered in Koobi Fora, Kenya by Richard Leakey and H. Mutua in 1969. This species is grouped with the Australopitecine genus, Paranthropus boisei because of the robusticity of the skull and the prominent characteristics. This species was found well preserved with a complete cranium but lacking dentition. He was known for his robust cranial features that showed the signs of adaptation of the ecological niches. The big chewing muscles attached to the sagittal crest are traits of this adaptation.

<i>Homo erectus</i> Extinct species of archaic human

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.

<i>Australopithecus sediba</i> Two-million-year-old hominin from the Cradle of Humankind

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 is interpreted as having 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.

<i>Homo gautengensis</i> Name proposed for an extinct species of hominin from South Africa

Homo gautengensis is a species name proposed by anthropologist Darren Curnoe in 2010 for South African hominin fossils otherwise attributed to H. habilis, H. ergaster, or, in some cases, Australopithecus or Paranthropus. The fossils assigned to the species by Curnoe cover a vast temporal range, from about 1.8 million years ago to potentially as late as 0.8 million years ago, meaning that if the species is considered valid, H. gautengensis would be both one of the earliest and one of the longest lived species of Homo.

<span class="mw-page-title-main">LD 350-1</span> Earliest known specimen of the genus Homo

LD 350-1 is the earliest known specimen of the genus Homo, dating to 2.8–2.75 million years ago (mya), found in the Ledi-Geraru site in the Afar Region of Ethiopia. The specimen was discovered in silts 10 m (33 ft) above the Gurumaha Tuff section of the site by Ethiopian palaeoanthropologist Chalachew Seyoum on 29 January 2013. It is currently unassigned to a species, and it is unclear if it represents the ancestor to H. habilis and H. rudolfensis which evolved around 2.4 mya.

<span class="mw-page-title-main">Dmanisi hominins</span> Hominid species or subspecies discovered in Dmanisi, Georgia

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 1.85–1.77 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.

References

  1. 1 2 Leakey, R. E. F. (1973). "Evidence for an Advanced Plio-Pleistocene Hominid from East Rudolf, Kenya". Nature. 242 (5398): 447–450. Bibcode:1973Natur.242..447L. doi:10.1038/242447a0. PMID   4700897. S2CID   4294312.
  2. Tobias, P. V. (1980). ""Australopithecus afarensis" and A. africanus: Critique and an alternative hypothesis". Palaeontologica Africana. 23: 3–4. hdl:10539/16335.
  3. White, T. D.; Harris, J. M. (1977). "Suid Evolution and Correlation of African Hominid Localities". Science. 198 (4312): 20. Bibcode:1977Sci...198...13W. doi:10.1126/science.331477. JSTOR   1744153. PMID   331477. S2CID   26551330.
  4. Mcdougall, I.; Brown, F. H.; Vasconcelos, P. M.; Cohen, B. E. (2012). "New single crystal 40Ar/39Ar ages improve time scale for deposition of the Omo Group, Omo-Turkana Basin, East Africa". Journal of the Geological Society. 169 (2): 213–226. Bibcode:2012JGSoc.169..213M. doi:10.1144/0016-76492010-188. S2CID   128606182.
  5. Walker, A.; Leakey, R. E. F. (1978). "The Hominids of East Turkana". Scientific American. 239 (2): 64–65. Bibcode:1978SciAm.239b..54W. doi:10.1038/scientificamerican0878-54. JSTOR   24960354. PMID   98842.
  6. 1 2 3 4 Kaplan, M. (2012). "Fossils point to a big family for human ancestors". Nature News. doi:10.1038/nature.2012.11144. S2CID   87482930.
  7. 1 2 3 Argue, D. (2017). "Homo rudolfensis". Encyclopedia of Evolutionary Psychological Science. Springer International Publishing. pp. 1–4. doi:10.1007/978-3-319-16999-6_3434-2. ISBN   978-3-319-16999-6.
  8. Wood, B. (1985). "Early Homo in Kenya, systematic relationships". In Delson, E. (ed.). Ancestors: The hard evidence. Alan R. Liss. ISBN   978-0-8451-0249-7.
  9. Valerii P. Alexeev, 1986, The Origin of the Human Race. Progress Publishers, Moskou
  10. Groves, C.P. 1989. A Theory of Human and Primate Evolution, Clarendon Press, Oxford
  11. Kennedy G.E. 1999. "Is 'Homo rudolfensis' a valid species?" Journal of Human Evolution36: 119-121
  12. 1 2 Wood, B. (1999). "Homo rudolfensis Alexeev, 1986: Fact or phantom?". Journal of Human Evolution. 36 (1): 115–118. doi:10.1006/jhev.1998.0246. PMID   9924136.
  13. Wood, B.; Collard, M. (1999). "The Human Genus". Science. 284 (5411): 65–71. Bibcode:1999Sci...284...65.. doi:10.1126/science.284.5411.65. PMID   10102822.
  14. Cameron, D. W. (2003). "Early hominin speciation at the Plio/Pleistocene transition". HOMO. 54 (1): 1–28. doi:10.1078/0018-442X-00057. PMID   12968420.
  15. 1 2 Bromage, T. G.; McMahon, J. M.; Thackeray, J. F.; Kullmer, O.; Hogg, R.; Rosenberger, A. L.; Schrenk, F.; Enlow, D. H. (2008). "Craniofacial architectural constraints and their importance for reconstructing the early Homo skull KNM-ER 1470". The Journal of Clinical Pediatric Dentistry. 33 (1): 43–54. doi:10.17796/jcpd.33.1.8168115j12103nut. PMID   19093651.
  16. 1 2 3 Leakey, M.; Spoor, F.; Dean, M. Christopher; Feibel, Craig S.; Antón, Susan C.; Kiarie, Christopher; Leakey, Louise N. (2012). "New fossils from Koobi Fora in northern Kenya confirm taxonomic diversity in early Homo". Nature. 488 (7410): 201–204. Bibcode:2012Natur.488..201L. doi:10.1038/nature11322. PMID   22874966. S2CID   4431262.
  17. Margvelashvili, A.; Zollikofer, C. P. E.; Lordkipanidze, D.; Peltomäki, T.; Ponce de León, M. S. (2013). "Tooth wear and dentoalveolar remodeling are key factors of morphological variation in the Dmanisi mandibles". Proceedings of the National Academy of Sciences. 110 (43): 17278–83. Bibcode:2013PNAS..11017278M. doi: 10.1073/pnas.1316052110 . ISSN   0027-8424. PMC   3808665 . PMID   24101504.
  18. Lordkipanidze, D.; Ponce de León, M. S.; Margvelashvili, A.; Rak, Y.; Rightmire, G. P.; Vekua, A.; Zollikofer, C. P. E. (2013). "A Complete Skull from Dmanisi, Georgia, and the Evolutionary Biology of Early Homo". Science. 342 (6156): 326–331. Bibcode:2013Sci...342..326L. doi:10.1126/science.1238484. ISSN   0036-8075. PMID   24136960. S2CID   20435482.
  19. Tattersall, I. (2001). "Classification and phylogeny in human evolution". Ludus Vitalis. 9 (15): 139–140. Archived from the original on 2021-04-15. Retrieved 2020-06-08.
  20. 1 2 3 4 5 6 Ungar, P. S.; Grine, F. E. (2006). "Diet in Early Homo: A Review of the Evidence and a New Model of Adaptive Versatility". Annual Review of Anthropology. 35: 208–228. doi:10.1146/annurev.anthro.35.081705.123153.
  21. Strait, D.; Grine, F.; Fleagle, J. G. (2015). "Analyzing Hominin Hominin Phylogeny: Cladistic Approach" (PDF). In Henke, W.; Tattersall, I. (eds.). Handbook of Paleoanthropology (2nd ed.). Springer. p. 2006. doi:10.1007/978-3-642-39979-4_58. ISBN   978-3-642-39979-4. Archived from the original (PDF) on 2020-06-12. Retrieved 2020-06-15.
  22. Strait, D.; Grine, F. E.; Fleagle, J. G. (2014). "Analyzing Hominin Phylogeny: Cladistic Approach". Handbook of Paleoanthropology (2nd ed.). Springer. pp. 2005–2006. ISBN   978-3-642-39979-4.
  23. Villmoare, B.; Kimbel, W. H.; Seyoum, C.; et al. (2015). "Early Homo at 2.8 Ma from Ledi-Geraru, Afar, Ethiopia". Science. 347 (6228): 1352–1355. Bibcode:2015Sci...347.1352V. doi: 10.1126/science.aaa1343 . PMID   25739410.
  24. Zhu, Z.; Dennell, R.; Huang, W.; Wu, Y.; Qiu, S.; Yang, S.; Rao, Z.; Hou, Y.; Xie, J.; Han, J.; Ouyang, T. (2018). "Hominin occupation of the Chinese Loess Plateau since about 2.1 million years ago". Nature. 559 (7715): 608–612. Bibcode:2018Natur.559..608Z. doi:10.1038/s41586-018-0299-4. PMID   29995848. S2CID   49670311.
  25. Holloway, R. L. (1983). "Human Paleontological Evidence Relevant to Language Behavior". Human Neurobiology. 2 (3): 109–110. PMID   6421780.
  26. 1 2 McHenry, H. M.; Coffing, K. (2000). "Australopithecus to Homo: Transformations in Body and Mind". Annual Review of Anthropology. 29: 125–146. doi:10.1146/annurev.anthro.29.1.125.
  27. Hawk, J. D. (31 March 2007). "KNM-ER 1470 is not a microcephalic". John Hawks Weblog. Retrieved 6 June 2020.
  28. 1 2 3 4 Wood, B. (1993). "Rift on the record". Nature. 365 (6449): 789–790. Bibcode:1993Natur.365..789W. doi: 10.1038/365789a0 . PMID   8413663. S2CID   4345234.
  29. 1 2 Schrenk, F. (1997). "UR 501, the Plio-Pleistocene hominid from Malawi. Analysis of the microanatomy of the enamel". Comptes Rendus de l'Académie des Sciences, Série IIA. 325 (3): 231–234. Bibcode:1997CRASE.325..231R. doi:10.1016/S1251-8050(97)88294-8.
  30. 1 2 Will, M.; Stock, J. T. (2015). "Spatial and temporal variation of body size among early Homo". Journal of Human Evolution. 82: 15–33. doi: 10.1016/j.jhevol.2015.02.009 . PMID   25818180.
  31. Dávid-Berrett, T.; Dunbar, R. I. M. (2016). "Bipedality and hair loss in human evolution revisited: The impact of altitude and activity scheduling". Journal of Human Evolution. 94: 72–82. doi:10.1016/j.jhevol.2016.02.006. PMC   4874949 . PMID   27178459.
  32. Pontzer, H. (2012). "Ecological Energetics in Early Homo". Current Anthropology. 56 (6): 346–358. doi:10.1086/667402. S2CID   31461168.
  33. Braun, D. R.; Aldeias, V.; Archer, W.; et al. (2019). "Earliest known Oldowan artifacts at >2.58 Ma from Ledi-Geraru, Ethiopia, highlight early technological diversity". Proceedings of the National Academy of Sciences. 116 (24): 11712–11717. Bibcode:2019PNAS..11611712B. doi: 10.1073/pnas.1820177116 . PMC   6575601 . PMID   31160451.