human skull 1.8 million years ago and superbly preserved today in the light emerges officially for direct entry to the history of paleontology. It has been found in Dmanisi, Georgia, a site which unearthed from the past two decades the fossils of the earliest hominids far beyond Africa. It is a grown man’s skull with a small brain, very primitive, arches protruding forehead, large jaw with good teeth and bulky muscles of mastication, the individual would be short in stature but his body would have already proportions of modern man, with long legs and short arms. He suffered arthritis in the jaw and has a fractured and healed area, who knows if an accident or a fight. Scientists, after five years of exhaustive study of the skull, the number 5 of Dmanisi and still no nickname to recognize easily say it is a very primitive form of early Homo, of the same species as those found in Africa just over Two million years. Some respected paleontologists who have seen him qualify him as the “fossil” icon. Because of his age (almost twice as many years, for example, that older individuals Atapuerca) and their characteristics, the number 5 of Dmanisi is located right in the vortex of the debate on the evolutionary origin of the genus Homo.
discovery authors, led by David Lordkipanidze, claim it is the first skull of the world until now completely preserved adult hominid such antiquity, those 1.8 million years, which shows that early Homo dispersed outside Africa shortly afterwards (in paleontological times) of its emergence and that the hitherto classified as human species that period are actually one. “It’s a fantastic specimen, great no matter how you classify it, this skull and other Dmanisi are among the best evidence we have about how, where, when and why humans evolved,” summarizes the American paleoanthropologist Tim White on a Comment Science , which discloses the skull.
Dmanisi is a small medieval town situated on top of a hill 80 km from the Georgian capital, Tbilisi. “30 years ago, during an excavation, discovered a sediment containing animal bones: after ancient stone tools appeared and hominid fossils”, recapitulates Lordkipanidze, director of the National Museum of Georgia. Already found remains of at least five individuals: an adult male aged and toothless, two other adult males, one female and a teenager whose sex has not been determined.
Number 5 was discovered in two stages of excavation: 2000 jaw and skull in five years, but scientists are confident that they fit perfectly, they are the same individual, despite the surprise of finding a very primitive small skull (the brain was about 450 cubic centimeters, compared to 1,350 in the current human species) and a more modern face, but with the nose protruding. It would measure between 1.46 and 1.66 meters tall and weigh between 47 and 50 kilos.
is a “fossil” icon, scientists say they have already seen
At the site, which is still digging, have appeared lithic pieces of human remote those used to fleshing animals, and many fossil remains of plants and wildlife, “including terrible saber-toothed tigers and cheetah Giant extinct, “said Ann Gibbons in Science . “The confrontation with the beasts would be running … and dangerous,” he adds. The five Dmaniasi hominids were found in underground cavities that could be holes to which animals would drag their prey. The area, 1.8 million years ago, enjoyed a mild and moderately wet.
Dmanisi researchers, given the characteristics of the fossils, had proposed a new species for these hominids: Homo georgicus . However, change of interpretation by presenting the skull No. 5, which agitate the international scientific debate about the first species of the genus Homo. They claim, first, that among the five Dmanisi individuals appreciate the differences are no greater than those between five current and five chimpanzees.
would an individual of small stature and brain still small
But also propose that the Georgian town is not fundamentally different from contemporary African-or shortly before, which until now have been classified as different species ( Homo habilis and Homo Homo rudolfensis erectu s) within the genus Homo. “This implies the existence of a single evolutionary lineage of early Homo,” say Lordkipanidze and colleagues, they encompass all these forms in a single species, H. erectus , including the Georgian population.
“This new skull confirms that Dmanisi fossils are what they seem: an early form of H. erectus , or rather, his oldest African variant, which some call Homo ergaster “, pointsThere class=”texto_grande”>
Thus the number 5 Dmanisi skull suggests that more than several ecologically specialized species of Homo, there is only able to function in different ecosystems.
is a controversial proposal and a team of scientists, Philip Rightmire (Harvard University) is described as “small bomb,” according to Gibbons. The truth is that even seems to be agreement among scientists about whether the five individuals of Dmanisi are a single species or not, so the great skull No. 5 is released by opening a good controversy.
“An important conclusion of the proposed Homo erectus as a single species is that the evolutionary pattern at that time is linear and unbranched,” said Arsuaga. “That is, there has only been an evolutionary line within the genus Homo, not two. I think it remains to be seen.” In any case, he continues, “the number 5 Dmanisi skull is a spectacular fossil, only full no other equally (or even more) in the fossil record: the skull No. 5 [to the name matches] of the Pit of Bones Atapuerca “.
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