Three have turned into five. Laetoli’s area in the north of Tanzania are a site of the cult ancient marks left here about 3,6 million years ago. Then three representatives of a species of the known primacy of Australopithecus afarensis – the ancient ancestor of the person — crossed this area big steps. But recently one more discovery has been made: scientists have found traces of two more individuals.
14 more prints of legs have been added to earlier found 70 traces. Opening was so surprising that “we couldn’t utter words”, Marco Cherin from the Italian University of Perugia says.
New finds of prints of feet can cardinally change idea of scientists of Laetoli’s area and of social life of A. afarensis. Besides, they can tell even about style of walking of ancient primacies and their ideas of family life.
For the first time traces on Laetoli’s site have been found in 1976. Nothing to researchers was possible to find similar before – the most ancient traces гоминин. The most ancient they remain and today. Scientists have christened that site “the place of G”.
Prints of feet have remained absolutely in a random way as many years ago the A. afarensis group passed on a damp volcanic ash which remained that very short time and has soon turned into a firm tufa (light, hardpan, porous rock). “Geophysics say what hardening process, has to be, occurred in only several hours” — Cherin says.
New opening (as it often happens) was made absolutely accidentally. Local authorities wanted to construct near Laetoli the museum for involvement of tourists therefore officials asked the researcher Fidelis Masao to study from University of Dar es Salaam what impact construction works will make on the valuable land area.
It and his colleagues dug out about 65 holes better to estimate amount of a layer of a volcanic ash in which traces also were found. However specialists found new traces in one hole. As a result archeologists including Cherin, started their studying.
“It is surprising that nearly four decades later after the first opening new traces in the same places were found. They could be left on the same day millions years ago” — William Jungers from University of New York in Hundred-uni – Brook says.
New “set” of traces belonged to two individuals. Prints were found in the place which anthropologists christened “site S”. It is approximately in 150 meters to the South from those traces which were found earlier. New traces are surrounded by dozens of others, left various animals – rhinoceroses, giraffes and horses. But what is interesting: the marks of A. afarensis found recently, most likely, were left on the same surface and at the same time, as the first prints. Also all this group in one direction and with an identical speed moved.
The analysis of all traces assumes that males and females of the died-out type of A. afarensis could differ significantly by the size. The similar difference, in turn, assumes that this type probably in the course had a polygamy – males had several females, scientists note.
The matter is that the previous researches showed: polygamy leads to the high competition between males that also promotes appearance of larger men. The last can cope with the rivals much better.
“It seems to me that such opening can be very useful for a fossiliya – knowledge which can be used for the solution of many questions concerning various aspects of life of prehistoric people” — Masao says.
Researchers have studied each new print and distance between traces — these data allow to estimate the size and weight of ancient primacies. Possibly, the male was growth in 1,65 meters, and weighed no more than 45 kilograms. The similar characteristic makes him the largest representative of A. afarensis among those whose remains or traces have been found earlier.
Other trace belonged to a female who was growth in 1,46 meters, and weighed no more than 40 kilograms, experts note. By the way, the last was three-four centimeters higher, than other female representatives, whose traces have been found in Laetoli earlier, experts say. Also she on the whole 30 centimeters was higher than famous Lucie.
And if to compare new traces with found earlier, then it is possible says that “several ancient orthograde гоминин moved as a part of group on this area”, scientists add.
It is previously possible to draw a conclusion that the group consisted of one male and two or three females, and also one or two cubs. Possibly, Cherin, a male says (therefore, and other males of this look) could have the whole harem from several females.
Such opinion differs markedly from conclusions of the previous researches which assumed that males of A. afarensis were monogamous. However, Cherin considers that, of course, new conclusions still should be checked carefully.
Future researches will be directed to excavation of new traces which, perhaps, will help to understand better life of the Australopithecus Afar.