Homo antecessor

Homo antecessor Fossil range: Pleistocene
File:Homo antecessor.jpg
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Primates Family: Hominidae Subfamily: Homininae Genus: Homo Species: H. antecessor
Binomial name
†Homo antecessor Bermudez de Castro et al., 1997

Homo antecessor is an extinct hominin and a potential distinct species that was discovered by E. Carbonell, J. L. Arsuaga and J. M. Bermúdez de Castro. They are one of the earliest known hominins in Europe, with those from the site of Dmanisi being older. The best preserved fossil is a maxilla which belonged to a 10 year old individual found in Spain. Based on palaeomagnetic measurements, it is thought to be older than 780-857 ka (Falguères et al., 1999:351). The average brain was 1000cc in volume. In 1994 and 1995, 80 fossils of six individuals that may have belonged to the species were found in Atapuerca, Spain. At the site were numerous examples of cuts on the bones, which indicates that H. antecessor could have practised cannibalism. Many anthropologists believe that Homo antecessor is either the same species or direct antecedent to Homo heidelbergensis, who inhabited Europe from 600,000 to 250,000 years ago in the Pleistocene. It is suggested that this is the last common ancestor of Homo neanderthalensis and Homo sapiens. No specimens of the species have yet been found in Africa.

Findings

Gran Dolina

Archaeologist Eudald Carbonell i Roura of the Universidad Rovira i Virgili in Tarragona, Spain and paleanthropologist Juan Luis Arsuaga Ferreras of the Universidad Complutense in Madrid, Spain discovered Homo anteccesor remains at a site in Northern Spain known as Gran Dolina in the Atapuerca Hills (near Burgos). Over 80 bone fragments from six individuals were uncovered in 1994 and 1995. The site had also included roughly 200 stone tools and about 300 animal bones. Stone tools including a stone carved knife were found along with the ancient hominin remains. All these remains were dated as being at least 780,000 years old. The best preserved remains are a maxilla (upper jawbone) and a frontal bone of an individual who died at 10-11 years old.

Atapuerca: The Oldest Human Fossils in Europe

The Sierra de Atapuerca site is located to the east of the city of Burgos. In this small hill is the evidence for the presence of early hominids which date over the course of the last one million years. Several archaeological and palaeontological sites have been found in the Atapuerca hills, some of them appeared during the construction of a railway trench (Gran Dolina, Galería, Elefante) and another one is located deep in the cave, "Sima de los Huesos" (Pit of the Bones). The Homo antecessor remains have been found in the level 6 of the Gran Dolina site (also called level TD6). Caves in the area have yielded stone artefacts and remains of the earliest known examples of hominids in Europe.

In the Sima de los Huesos the same team located more than 4,000 human bones with an age of 350,000 years old. Homo anteccesor is considered as one of the earliest hominids in Europe; the oldest discovery is Homo georgicus from the Republic of Georgia at 1.8 and 1.6 million years old. The fossil pit bones include a complete cranium and fragments of other craniums, mandibles, teeth, a lot of postcranial bones (femurs, hand and foot bones, vertebrae, ribs, etc.) and a complete pelvis. The pit contains fossils of perhaps 28 individuals together with remains of bears and other carnivores. Some scientists include this species as a portion of Homo heidelbergensis, a direct ancestor of Homo neanderthalensis ("Neanderthal Man") in Europe.

On 29 June 2007, Spanish researchers working at the Atapuerca Sierra site announced that they had recovered what is believed to be the oldest human fossil ever found in Europe.[1] Co-director of the research site, Jose Maria Bermudez de Castro, estimated that the molar discovered could be 1.2 million years old. "Since [the molar] is an isolated fossil...it is not possible...to confirm which Homo species this tooth belongs to, [however] first analyses allow that [it] is an ancestor of Homo antecessor (pioneer)," read a statement released by the Atapuerca Foundation. In 1994 at Gran Dolina, a site close to the Atapuerca Sierra site, H. antecessor, fossils approximately 800,000 years old were retrieved. Discoveries following the latter have supported the plus-800,000 B.P. date. Before this discovery, fossils of bison, deer, bear and other animals had been uncovered.

The molar was discovered in the Sima del Elefante section of the Atapuerca site. Bermudez de Castro, a paleontologist, described the fossil as "well worn" and from an individual between 20 and 25 years of age. While the fossil awaits further testing, "the geological level [strata] where the tooth was found make it the oldest European to date," he said further.

Recent discoveries at the Atapuerca site have unearthed human remains spanning time periods from early humans, to the Bronze Age as well as modern man (Homo sapiens sapiens).

Physiology

Homo antecessor was about 5 and a half to 6 feet tall, and males weighed roughly 200 pounds (91 kilograms). Their brain sizes were roughly 1000-1150cc, smaller than the 1350cc average of modern humans. Due to its scarcity, very little more is known about the physiology of Homo antecessor, yet it was likely to have been more robust than H. heidelbergensis. According to Juan Luis Arsuaga, one of the co-directors of the excavation in Burgos, the Homo antecessor might be right-handed which makes him different from the rest of apes. The hypothesis is based on tomography techniques. Arsuaga also claims that the frequency range of audition is similar to Homo sapiens' which makes him believe that Homo antecessor used a symbolic language and was able to reason [1]. Arsuaga's team is currently pursuing a DNA map of Homo antecessor after elucidating that of a bear that lived in northern Spain some 500,000 years ago.

Basing on teeth eruption pattern, the researchers think that Homo antecessor had the same development stages as Homo sapiens, though probably at a faster pace. Other features acquired by the species are a protruding occipital bun, a low forehead and a lack of a chin. Some of the remains are almost indistinguishable from the fossil attributable to KNM-WT 15000 (Turkana Boy) belonging to Homo ergaster.

References

• [1] El Mundo newspaper (in Spanish)
• BBC - Dawn of Man (2000) by Robin Mckie ISBN 0-7894-6262-1
• http://www.jqjacobs.net/anthro/paleo/antecessor.html
• http://www.mnh.si.edu/anthro/humanorigins/ha/a_tree.html
• http://www.geocities.com/palaeoanthropology/Hheidelbergensis.html