Homo antecessor

Replica of a skull residue

• Spain ( Burgos province )

As Homo antecessor fossils of the genus Homo are referred to, which were discovered in northern Spain in up to 900,000 -year-old finds from the Pleistocene layers. According to its discoverers, the facial bones of the finds relatively "modern" features, while the crowns and roots still show "primitive" features, which was not observed in this combination at approximately equal old Homo heidelbergensis.

The classification of Homo antecessor as an independent species, as well as the relationship with other species of the genus Homo is controversial.

Naming

The name of the genus Homo is derived from the Latin homo [ hɔmo ː ] "man." The epithet antecessor also comes from Latin and means approximately precursor, explorers, pioneers, early settlers. Homo antecessor thus means something like " forerunner of anatomically modern humans ".

Locality

The Sierra de Atapuerca, located 14 km east of Burgos, is a karst landscape in the Cretaceous dolomite were formed numerous caves. These caves were later gradually filled with Pleistocene deposits and were known that you could find in them fossilized bones for a long time. 1976 where she discovered the Spanish paleontologist Trinidad Torres in search of fossil bear bones the first fossil members of the genus Homo. The Karst Hills of Atapuerca turned out rapidly as the world's most important repository of fossils from the Middle Pleistocene and were initially dated to the period 780000-125000 years before present. Alone from one of these caves, the Sima de los Huesos ( " bone pit " ), more than 1,300 fossils were up to 1993 have been recovered, which could be assigned to the genus Homo.

The finds are kept in the Museo Nacional de Ciencias Naturales in Madrid and an archaeological collection in Burgos.

First description

Near the Sima de los Huesos several caves were raised in 1900 during the construction of a now disused mine - railway, was where also dug since 1978. In this in one of these caves in 1990 - called Gran Dolina ( " Large sinkhole " ) - discovered by Juan Luis Arsuaga stone tools, in layers, whose age has been dated to nearly a million years. This contradicted the previously valid assumption that Europe was populated only 500,000 years ago Homo.

Began in 1993 under the direction of Eudald Carbonell in the Gran Dolina cave, systematically remove a six -square-meter, 18 -meter-thick deposit. In July 1994, the genus Homo attributable to bone fragments and teeth as well as around 100 stone tools were unearthed in the layer known as the TD6 - T36 -43. On the basis of associated finds (including various rodent species), the shape of the stone tools and paleomagnetic measurements, the fossils of the TD6 layer were initially estimated at an age of 780,000 years, since this layer under the datable at this age Matuyama - Brunhes boundary ( also: Brunhes - Matuyama magnetic reversal) is. At the same time the discovery indicated that they had assigned to any of the established species of the genus Homo, the finds. They explained that they could keep the fossils for " a primitive form of Homo heidelbergensis ", maybe you 'll call but also a new way, if other findings, this could seem appropriate.

Indeed, in May 1997 in the journal Science, the first description of a new species, Homo antecessor of published. Usually, however, quite small - - ​​Finds of at least six individuals " may last common ancestor of Neanderthals and modern humans " known as the remains of the and now - in it the now almost 80 were significantly different from the original dating - an age of " about 650,000 years " appreciated. Then but was again resorted to the original age of "at least 780,000 years," 1999. Dated 2008, a review article the fossils in the period 780000-500000 years before today. A recent dating in 2013 then even yielded an age of 900,000 years.

As holotype fragment of a right mandibular molars with the M1, M2 and M3 ( archive number ATD6 -5), the upper jaw fragment ATD6 -13 and another 12 the same individual attributed teeth was defined in the original description. Given the nature of the teeth (including premolars with multiple roots ) and the fragments found skulls of several factors (modern -looking face, but " primitive " pine and browridges ) was Homo ergaster considered as ancestors of the Gran Dolina - findings into consideration.

The Spanish researchers therefore decided to - controversial in the scientific world - interpretation of their findings as a new Chrono species: Homo ergaster from the African had developed in Spain, the European Homo antecessor and Homo heidelbergensis from this. Many other European paleoanthropologists, however, order the Asian hominin fossils of Altpleistozäns ( approximately 1.8 to 0.8 million years ago ) with those from Africa and Europe consistently the Homo erectus, so that - according to this reading - Homo erectus from Africa coming spread in Europe and developed here to Homo heidelbergensis; the Spanish fossils are from this point of view, therefore, - as, for example, barely younger southern France Homo erectus tautavelensis - to a local group of Homo erectus.

Further finds

In March 2008, a lower jaw was presented in Nature (archive number ATE9 -1), which was recovered in June 2007 from the Sima del Elefante and also - though explicitly "tentative " - Homo antecessor was attributed. This find was dated at 1.2 to 1.1 years, and would Mio., dating should be correct, the oldest find of individuals of the Hominini in Europe. 2011, the allocation to Homo antecessor was revoked and the fossil restrained than Homo spec. explicitly associated with a particular kind; the age has now been specified at 1.3 million years ago.

Homo antecessor may be able to also fossils from a quarry are assigned to Terni Fine ( Tighenif ) near Muaskar, Algeria: three lower jaw, a skull fragment and some teeth that had been found there in 1954 by French paleontologists Camille Arambourg. In the first publication of the finds have been designated as Atlanthropus mauritanicus, while today they are mostly referred to as Homo erectus mauritanicus.

Similarly old as Homo antecessor is known as finds a process called Homo cepranensis skull roof fragment was recovered in March 1994 in Italy and Homo antecessor " may " is near.

Researchers led by Chris Stringer laid in May 2013 at Happisburgh in East of England fossil footprints free, which they dated to an age of 800,000 years, Homo antecessor zuordneten under this age, as this species is the only one so far described in that era in Europe.

Controversy

The classification of Homo antecessor as a separate species, which is represented by Spanish paleoanthropologists from the start was - between so-called Lumpern and splinters - controversial. Already in 1997, criticized the French paleoanthropologist Jean -Jacques Hublin from the Centre national de la recherche scientifique in Science that the new type has been defined based on facial bones of a young person, especially; also the lower jaw fragment ATD6 -96 probably originates from a young woman. That a further gradation of species ipso facto, not a, - From the period between 1.8 million and 500,000 years ago, today we know so few homo- fossils from Europe, towards other researchers - for example, Philip Rightmire of the State University of New York was appropriate; also you hardly know youthful face skull from other sites, so that comparisons with the fossil ATD6 -5 are hardly possible.

In many cases, the Homo antecessor be attributed to Homo erectus fossils therefore assigned or interpreted as earlier Homo heidelbergensis. Even Eudald Carbonell, the longtime excavation director in Atapuerca, 2008 acknowledged, for example, that the lower jaw from the Sima del Elefante both the younger resemble Homo heidelbergensis and the Dmanisi fossils. According to his hypothesis, the fossils from Atapuerca are descended from the Dmanisi people who are said to have spread to Spain; a contrary speculation states that the population described as Homo antecessor as a candidate for the last common ancestor of humans and Dmanisi Homo heidelbergensis could come into question.

In a review article on the origin of Homo sapiens Jeffrey H. Schwartz and Ian Tattersall questioned in 2010 the theory that Homo antecessor was the last common ancestor of Neanderthals and humans by pointing out that the two younger species to a few anatomical features with the alleged Vorläuferart divided, as that this hypothesis is plausible enough. At the same time, they pointed out that the dentition of the lower jaw finds from Spain and Algeria a very similar construction ( "detailed similarities " ) having. If both belong to the same species, would have the older term Atlanthropus mauritanicus priority; Homo antecessor would have to take place - today's conventions, according to - the species name Homo erectus or mauritanicus mauritanicus be used.

Maybe those referred to as Homo antecessor fossils of the document are for an early settlement in the region of Atapuerca by a population that is later died out again.