Homo habilis

The Homo habilis -from Latin homo , ‘man’, and habilis , ‘hábil’- is a hominid extinct that lived in Africa at the beginning and middle of the Pleistocene , between 2.5 and 1.5 million years ago. The discovery of this species is due to Mary and Louis Leakey , who found the fossils in Tanzania ( Africa ), between 1962 and 1964. When it was discovered it was considered the oldest species of the genus Homo , a position later occupied by Homo rudolfensis . [one]

Summary

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  • 1 Description
  • 2 Physical characteristics
    • 1 Differences with australopithecines
    • Homo habilisand Homo erectus
  • 3 Main deposits and fossil remains
    • 1 Kada Hadar (Ethiopia)
    • 2 Shungura, and Lower Omo Valley (Ethiopia)
    • 3 Chemeeron (Kenya)
    • 4 Koobi Fora (Kenya)
    • 5 Olduvai Gorge (Tanzania)
    • 6 Sterkfontein (South Africa)
    • 7 Swartkrans (South Africa)
  • 4 See also
  • 5 Sources

Description

His name means ‘skillful man’ and refers to the discovery of lithic instruments probably made by him. [2] Detailed studies of the skeletal remains of his hands have been carried out to verify if it really would be possible that this Homo had made them. The scientists concluded that it was capable of grasping to carry out the necessary manipulations in the manufacture of stone utensils; probably, it was an opportunistic carnivore , that is, a scavenger , but it is an extreme that we do not know yet. [one]

An important increase in brain size is observed in them with respect to Australopithecus , which has been calculated between 510 cm³ and 600 cm³. [3]

Most of the remains have been found in Kenya , in the town of Koobi Fora and in Tanzania , in the well-known “Olduvai gorge”. [4]

Some authors [5] question its belonging to Homo , according to a restrictive interpretation of the diagnosis of the genus , and assign it either to Australopithecus or propose that a new genus be defined for this species in which it also includes the Homo rudolfensis .

Physical characteristics

The main characteristics are the following: [6]

  • More rounded skull.
  • Face less prognathic than australopithecines .
  • Incisors larger than australopithecines.
  • Spadiform incisors (sword-shaped, pointed).
  • Large molars with thick enamel.
  • Absence of diastema .
  • The foramen magnum ( occipital hollow ) is located more towards the center.
  • Short face.
  • Curvedfingers and toes, indicating that they were still using the trees.
  • The bipedal position in females causes a reduction of the pelvis that has as a consequence an earlier parturition (which implies prematurity of the neonate, a longer time dedicated to rearing and thus the need to maintain strong social ties that potentially contribute to development of a culture ).
  • Greater cranial capacity (600 cm³).

Differences with Australopithecines

Analyzing some of the recovered bone remains, it can be recognized that it is a species with a much more human aspect than that found in australopithecines . The head of the femur is larger, shorter and more rounded. Also the pelvis has a more modern look.

Its height was similar to that of Australopithecus africanus , about 1.3  m and an average weight of 52 kg for males and 32 kg for females. [7]

Homo habilis and Homo erectus

Findings made in northeast Africa ( Lake Turkana area ) by Louise and Meave Leakey (daughters of Louis and Mary Leakey ) published in 2007 approximate the existence of Homo habilis to more recent dates: up to at least 1.44 Ma (millions of years ) Before the present, such dating implies that Homo habilis and Homo erectus coexisted in the same territories for at least 500,000 years , the researchers believe that initially there should not have been major conflicts between the two species, however population growth of Homo erectusit would have ended with a struggle for resources from which Homo erectus would have emerged successfully . That same finding casts doubt – on the other hand – a direct affiliation between the two species. Although there are authors such as Erik Trinkaus who believe that coexistence does not rule out that Homo habilis was a direct ancestor of H. erectus . [8]

Main deposits and fossil remains

Kada Hadar ( Ethiopia )

  • AL 666-1: Part of the skull with teeth 2.33 Ma (million years) old. It would be the oldest skill if confirmed, since there are doubts in the attribution. [9]

Shungura, and Lower Omo Valley ( Ethiopia )

  • OMO 75-14: Upper jaw with part of the teeth and some parts of the skull from 2.12 Ma (millions of years) ago. Its usual attribution is to Homo rudolfensis although it is in doubt. [9]
  • L894-I: Partial skull, more graceful than OMO 75-14, but also with attribution doubts. Dated at 1.88 Ma (millions of years).

Chemeeron ( Kenya )

  • KNM-BC 1or Chemeeron temporal: Part of a temporal bone from a skull dated 2.4 Ma (million years). [10] Doubts of attribution between Homo habilis , Homo rudolfensis or Homo [11] [12]

Koobi Fora ( Kenya )

  • KNM-ER 1805: Three skull fragments of an adult individual, dated at 1.74 Ma (millions of years); [13] [14] [4]
  • KNM-ER 1813: Quite complete skull of 510 cm³ capacity and dated at 1.78 Ma (millions of years). Discovered by Kamoya Kimeu in 1973. [15] [16] [17]
  • KNM-ER 1470or Rudy , initially interpreted as Homo habilis , is currently assigned to a different species, Homo rudolfensis . [18]

Throat Olduvai ( Tanzania )

  • OH 7: Lower jaw with 13 teeth, one lower molar, two parietals and 21 bones of the fingers, left hand and wrist. This set of fossils is the holotype of the species. The cranial capacity has been estimated by different researchers between 363 and 710 cm³. The remains belonged to a young male, 12 or 13 years old and have been dated at 1.75 Ma (millions of years). They were discovered by Jonathan Leakey | Jonathan and Mary Leakey in 1960. Homo habilis was described on the basis of these remains in 1964 by Leakey, Tobias, and Napier. [19] [20]
  • OH 8: Most of the bones of a foot of 1.75 Ma (million years). It could probably be related to OH 10 and, with more doubts, to OH 35. [21] [22]
  • OH 13or Cinderella: Fragments of the jaw, maxilla and teeth of a possible female, dated at 1.7 Ma (millions of years). Discovered by N. Mbuika in 1963. [23] [24] [25]
  • OH 16or George: Calota of a skill of 1.7 Ma (million years). [26]
  • OH 24or Twiggy: A skull, which was found very deformed. After restoration, a capacity of just under 600 cm³ has been estimated. It was located by Peter Nzube in 1968. [27] [28]
  • OH 35: Tibia 1.8 million years old. OH 35 could be part of the same individual as other fossils, OH 8 and OH 10, although there are more doubts than in the relationship between them. [21] [22] [29]
  • OH 62or hominid Dik-Dik: Set of fossil remains that includes upper and lower limbs, discovered by Donald Johanson and Tim White in 1986. [30]
  • OH 65: Upper jaw with most teeth, found by Amy Cushing and Agustino Venance in 1995. [31] [32] [33]

Sterkfontein ( South Africa )

  • StW 53: A skull, located at “Member 5” and dated at 1.8 Ma (millions of years) and whose attribution to the habilis is doubtful. It has also been classified as a Homo habilis sensu lato, a holotype of Homo gautengensis, or simply unclassified.

Swartkrans ( South Africa )

  • SK 847: A partial skull that includes left part of the face and temporal bone, part of the upper jaw. It shows characteristics of  ergaster and others of Homo habilis , which have led it to be classified as a Homo habilis sensu lato, an unclassified Homo , and, even at first, a Paranthropus robustus (Austrolapithecus robustus) . [34] This fossil has made it possible, along with others, to study the evolution of the ear (Spoor et al. , 1994). [34] [35

 

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