The first australopithecine 2,500 kilometres west of the Rift Valley (Chad), Nature, 1995, 378, pp. 273-275.
Australopithecus bahrelghazali, une nouvelle espèce d'Hominidé ancien de la région de Koro Toro (Tchad). Comptes rendus des séances de l'Académie des Sciences, 1996, vol. 322, pp. 907-913.
Australopithecus bahrelghazali ('Abel) discovered at KT12 by Mamelbaye Tomalta, January 23, 1995 (Alain Beauvilain, photographs of January 26, 1995, after the original), dated around 3.5 million years.
- The dark brown color of teeth is due to the minerals present in the geological layer that stained enamel during fossilization.
- The size of canine, barely longer than the adjacent teeth, and the absence of diastema (space existing in all monkeys between canines and bicuspids for receiving the protruding portion of the opposite canine) are criteria humanization. The incisor of quasi-human form and the profile of the mandibular symphysis is almost vertical, as is the chin in humans, indicating a relatively flat surface. On the other hands, the presence of three roots of the premolars (one in man today, sometimes two, rarely three) is rather a primitive character.
- The wear facets of teeth indicate permanent teeth of a young adult. The horizontal stripes visible on the base of the teeth are dysplasias due to a defect in the mineralization of enamel during the growth of the teeth due to a dietary deficiency or disease. Abel would have had such problems at least twice as evidenced by the two canine dysplasia. Given the context, Abel would there have been hunger during droughts?
- X-rays revealed a thick enamel, human nature, while in monkeys, it is thinner.
In January 1994, the National Center for Research Support (CNAR) organizes for Professor Michel Brunet, a paleontologist at the University of Poitiers, a paleontology mission in the Chadian desert. Participants include Michel Brunet, Alain Beauvilain, geographer to the service of CNAR as head of the "Project Support to scientific research in Chad'' of the Fund for Aid and Cooperation of the French Republic, Augustin Deat, geological engineer at the Centre of Geological and Mining Research (CRGM) of Garoua (Cameroon), Sergio Scarpa Falce, tour operator who provided the logistics of this mission, François Beauvilain, Ali Hamit Moutaye, geological engineer at the Mining Project of the Directorate of geological and mining Researches (DRGM), project funded by the United Nations Development Programme (UNDP), Darnan Darnass, botanist at the Faculty of Exact and Applied Sciences of N'Djamena, Mahamat Oueddey, guide in Kouba Olanga.
On the basis of information provided to Alain Beauvilain by Louis Authosserre, hydrogeologist, and with the collaboration of his guide, Mahamat Oueddey, guide in Kouba Olanga, mammals' eleven sites (KT1 to KT 11) are recognized at the East Koro Toro. They indicate a range of time of 3 to 4 million years. At the beginning, the paleontological surveys will widely appeal to the"hydrogeological map of recognition to 1 / 500,000. Explanatory's sheet Pays Bas - Largeau. Map establishes by Jean-Louis Schneider and publishes by the BRGM in 1968.
In January 1995, a second mission was organized with the objective, much further north, to recognize the cliff of Angamma (literally "The graves outside"), region where in 1961 the team of paleontologist Yves Coppens had unearthed a hominid fossil, the 'Tchadanthropus uxoris', the "Chad's man of the wife" (the fossil had been found by the cook of the mission who give it to the wife of Yves Coppens). Thus Sunday, January 22, 1995 around 15 pm, two vehicles are stop at about forty-five kilometers east of Koro Toro. They come back from the cliff of Angamma in the north of the Nether Lands of the Chad basin that passengers had to leave due to extremely high winds (over 100 km / h recorded at Faya). They had traveled more than 3000 km since leaving N'Djamena. They formed a team consisting of:
- Michel Brunet, Professor of Paleontology at the Poitiers' University;
- Ali Hamit Moutaye, Geological Engineer at the the Mining Project, a project that has loaned a vehicle;
- Alain Beauvilain, geographer, leader of the "Project Support to the Chadian scientific research";
- Najia Beauvilain, steward of this mission;
- Mamelbaye Tomalta, driver at the Mining Project;
- Mahamat Oueddey, guide atKouba Olanga;
- end Mahamat, trader by profession, who had asked to be transported from Faya to N'Djamena.
The team was on the way back without having found what Michel Brunettry to find in Chad since the previous year, hominid. Fort disappointed, he was eager to return to Cameroon to monitor the work of her team and said. However, he had accepted the proposal of Alain Beauvilain to go to the fossils sites recognized last year in order to see the work of erosion agents (winds and rains) since one year, the rains in 1994 having been abundant to the heart of the desert. Michel Brunet's life will be upset forever.
Indeed, so, from the top of a well-marked sand bar (whose name, "Goz Kerki" just means "sand bar") which limited here's 10.000-6.000 years the shores of a Mégatchad, the driver of the first vehicle, Alain Beauvilain, sees from afar dark masses laid on stretches of white sandstone. These are the fossilized bones of large animals that lived here there are three to four million years: ancestors of modern elephants, hippos, rhinos, giraffes, horses, gazelles, ... but also crocodiles, turtles, fish, .. .. This new site is only a few hundred meters from recognized sites the previous year!
The end of this afternoon is devoted to the collection of large pieces while Alain Beauvilain sets up a carroyage. A pig mandible already gives a first emotion to Professor Brunet ... but this is only a pig.
Kolpochoerus afarensis (Suidae) unearthed the 22 January 1995 on the site of KT12. Exceptionnaly fossil in situ on the site of KT12. 'this is only a pig...' but his presence on a site is often a harbinger of the presence of hominids. (photograph Alain Beauvilain).
Early on January 23, under the gaze of nomads came observe the activities of the curious visitor activities, each team member moves square by square by carefully observing each element contrasting with the more or less regular soil surface. Mamelbaye Tomalta, who was ill, joins to the work to 8:45 and almost immediately calls Professor Brunet to report him a fossil returned in the sand.
'Abel' on the site of its discovery 23 January 1995 between 8 am 45 and 9 am. Mandible appeared only the mandibular symphysis. This was the only part subject to erosion while, immersed in the sandy deposit, teeth were protected. Michel Brunet immediately began cleaning the sand grains embedded in the interstices (photographs Alain Beauvilain).
An important discovery in the History of Science has been done: the discovery of the mandible of Australopithecus in the sands of the Chadian desert, more than 2,500 kilometers from the nearest comparable discovery. In the enthusiasm of its discovery, hardly arrived in N'Djamena, mandible in hand, Michel Brunet gives an interview nearly a half hour to TéléTchad, national television. Should be notified to the Chadian population in the quality of fossil unearthed, especially if the fossil will long to Poitiers. President Idriss Deby will fetch Abel in Poitiers in February 2010.
In 1996, the discovery of two new fossils will enrich our knowledge of the Australopithecus bahrelgazali: in January 1996 at the sweeping on the same site, called KT12, Alain Beauvilain discovers an upper premolar belonging to a second individual of the same species; January 16, 1996 on the site of KT13, Mahamat Kasser, geological engineer at the Mining Project, discovers a fragment of left maxillary of another individual.
It must wait the mission of July 2000, authorised by Mr. Baba El Hadj Mallah, Director of CNAR, and with funding from the French Cooperation, for that Fanoné Gongdibé, an engineer at the Department of Mines and Geology, in service in CNAR, unearths, July 18, 2000, on the site of KT40, the mandible of another hominid.
These discoveries have been performed on the eight kilometers separating the three sites of KT12 and KT 40, KT13 being at 4500 meters of KT12 and 3500 meters of KT40. The topographical position of the three sites is almost identical. They are located at the foot of the Goz Kerki. KT12 (16 ° 00 '21 "N, 18 ° 52' 24" E) is immediately at the foot of this sand cord, KT40 (15 ° 56 '14 "N, 18 ° 52' 16" E) to fifty meters. KT13 (15 ° 58 '09 "N, 18 ° 52' 10" E) is little more distant, the fossil was collected in the sand on the sandstone about 200 meters of the cord (GPS coordinates are those of the fossil sites already indicated in scientific articles. Note that, on Google Earth, the geographic coordinates of the discovery of ‘Abel’, easily identifiable on the satellite image, indicate a difference of 360 meters with the location's reality).
Reflecting the obstinacy of researchers, the first and third discoveries occurred while the mission was on the way back ...
The discovery of Abel weakens the scenario called "East Side Story" which limited the origins of mankind in Eastern Africa and in Southern Africa, east of the Rift Valley. It allows the creation in 1996 of the Paleoanthropological Franco-Chadian Mission (MPFT), a scientific cooperation between the National Centre for Research Support (CNAR) and the University of N'Djamena, both agencies of the Ministry of Higher Education of the Republic of Chad, and the University of Poitiers.
This fossil was named informally 'Abel' in homage to Abel Brillanceau, geologist at the National School of Engineers of Poitiers and close friend of Michel Brunet, died the February 27, 1989 of a resistant malaria on the tarmac of the Garoua airport (Cameroon) inside the medical aircraft that should have him bring back in France. He participated the field missions of the PIRCAOC project (international research program in the West African Cenozoic and Cameroon) in the Benue’s basin.