Homo ergaster

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Homo ergaster
Fossil range: Pleistocene
Homo ergaster reconstruction. Museum of Man, San Diego, California.
Homo ergaster reconstruction. Museum of Man, San Diego, California.
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primates
Family: Hominidae
Tribe: Hominini
Genus: Homo
Species: H. ergaster
Binomial name
†Homo ergaster
Groves & Mazak, 1975

Homo ergaster ("working man") is an extinct hominid species (or subspecies, according to some authorities) which lived throughout eastern and southern Africa between 1.9 to 1.4 million years ago with the advent of the lower Pleistocene and the cooling of the global climate.

H. ergaster is sometimes categorized as a subspecies of Homo erectus. H. ergaster may be distinguished from H. erectus by its thinner skull bones and lack of an obvious sulcus. Derived features include reduced sexual dimorphism; a smaller, more orthognathic (straight jawed) face; a smaller dental arcade; and a larger (700 and 850 cm³) cranial capacity. It is estimated that H. ergaster stood at 1.9 m (6ft3) tall with relatively less sexual dimorphism in comparison to earlier hominins. Remains have been found in Tanzania, Ethiopia, Kenya, and South Africa.

Homo ergaster skull reconstruction. Museum of Man, San Diego, California.
Homo ergaster skull reconstruction. Museum of Man, San Diego, California.

The most complete Homo ergaster skeleton known was discovered at Lake Turkana, Kenya in 1984. Paleanthropologists Richard Leakey, Kamoya Kimeu and Tim White dubbed the 1.6 million year old specimen as KNM-WT 15000 (nicknamed "Turkana Boy").

The type specimen of H. ergaster is KNM ER 992[1]; the species was named by Groves and Mazak in 1975.

The species name originates from the Greek ergaster meaning "Workman". This name was chosen due to the discovery of various tools such as hand-axes and cleavers near the skeletal remains of H. ergaster. This is one of the reasons that it is sometimes set apart distinctly from other human ancestors. Its use of advanced (rather than simple) tools was unique to this species; H. ergaster tool use belongs to the Acheulean industry. H. ergaster first began using these tools 1.6 million years ago. Charred animal bones in fossil deposits and traces of camps suggest that the species made creative use of fire. Another notable characteristic of H. ergaster is that it was the first hominid to have the same body proportions (longer legs and shorter arms) as modern H. sapiens.[2]

Contents

[edit] Notable fossils

[edit] See also

[edit] References

  • Tattersall, Ian and Schwartz, Jeffrey. "Extinct Humans". Westview Press, Boulder, Colorado and Cumnor Hill, Oxford, 2000. ISBN 0-8133-3482-9 (hc)

[edit] External links

[edit] Footnote

  1. ^ KNM-ER 992 is short for: Kenya National Museum (where it is housed); East Rudolf (where it was found); and 992 (the museum acquisition number)
  2. ^ Standford,C.,Allen,J.S.,and Anton, S.C. "Biological Anthropology". Pearson Education, Upper Saddle River,New Jersey, 2006
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Part of the series on Human evolution

Sahelanthropus tchadensis • Orrorin tugenensis • Ardipithecus • Kenyanthropus platyops

Australopithecus: A. anamensis • A. afarensis • A. bahrelghazali • A. africanus • A. garhi Paranthropus: P. aethiopicus • P. boisei • P. robustus

Humans and Proto-humans

Homo: H. habilis • H. rudolfensis • H. georgicus • H. ergaster • H. erectus (H. e. lantianensis • H. e. palaeojavanicus • H. e. pekinensis • H. e. soloensis) • H. cepranensis • H. antecessor • H. heidelbergensis • H. neanderthalensis • H. rhodesiensis • H. floresiensis • H. sapiens (H. s. idaltu • H. s. sapiens)