The Skull of Quadruped and Bipedal Vertebrates. Djillali Hadjouis

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The Skull of Quadruped and Bipedal Vertebrates - Djillali Hadjouis

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Essonne, Seine-et-Marne and Val-d’Oise, most of which were cleared during the 19th and 20th centuries as a result of quarrying on the outskirts of Paris. The latter also had its share of discoveries, sometimes complete skeletons, such as that of the Montholon Square near the Montmartre cemetery. In the department of Val-de-Marne, several bony and dental remains of woolly mammoths (M. primigenius) have been found since the end of the 19th century on the banks of the Seine and its confluence with the Marne (Ardouin et al. 2009; Hadjouis 2020a). Thanks to the land development of the last 40 years carried out along the river banks, preventive archeological operations have brought to light new discoveries in well-dated biostratigraphic contexts.

      Although the remains of ancient mammoths and elephants unearthed in this small department of south-eastern Paris have been numerous (remains preserved at the Muséum national d’Histoire naturelle, Musée de Saint-Maur-des-Fossés and Musée d’antiquités nationales), most of them were transported and deposited on the banks of the Seine or in the loop of the Marne (Le Perreux, Nogent-sur-Marne, Saint-Maur-des-Fossés, Créteil, Valenton, etc.) without great chronostratigraphic precision.

      Appearing in Eastern Siberia around 800,000 years ago, the woolly mammoth’s existence was known in Western Europe 200,000 years ago in chronocultural contexts of the Middle Paleolithic. With the exception of some spectacular specimens, it is mainly mandibles, cranial portions or isolated teeth that are found during archeological excavations or chance discoveries. Among the fossils recently dated by radiometric methods (uranium/thorium and carbon 14), two stand out: the young mammoth from Maisons-Alfort and the skull from Bonneuil-sur-Marne.

      Usually, the attribution of Proboscidian species (Elephas, Loxodonta and Mammuthus) is based on complete third molars. It is indeed this last molar which delivers the greatest number of distinctive dental criteria (tooth shape, number of blade teeth and their index, enamel character and their plicature, sinus morphology, etc.). The milk tooth of the Maisons-Alfort baby mammoth was an incomplete lower third milky premolar (D3) with four blades (length: 36.2 mm; height: 44.6 mm).

      The inventory of Vertebrate faunas carried out at the request of the director of the Val-de-Marne Departmental Archaeology Laboratory, Philippe Andrieux, in the 1990s included a fossil, which exceeded in volume and significance all other bone and dental remains. The skull without mandible of a woolly mammoth, perfectly preserved, had been waiting to be studied since 1923.

      Without the short note Les gros blocs quaternaires du port de Bonneuil by Paul Lemoine and Teilhard de Chardin published in the journal La Nature in 1923, no one would know the exact origin of this Propboscidian. The authors describe the work carried out on Barbière Island, a commune of Bonneuil, located between the Marne and Morbras rivers, in order to dig the future coal port of Paris. The dredging of alluvium and blocks of local origin (coarse limestone with ceriths, Champigny limestone, Brie millstone and Fontainebleau sandstone) had yielded the fossil remains of M. primigenius and Bos. The woolly mammoth skull discovered during these dredging operations was not described in this note, but was obviously part of the port works.

      Another individual was found in the same conditions in Bonneuil-sur-Marne, notably a tusk with traces of anthropogenic cutting.

      As mentioned above, the Bonneuil-sur-Marne fossil was not found in welldocumented stratigraphic levels or in a chronocultural context of the Paris Basin. However, its fortuitous discovery during the dredging of the coal port works in 1923 does not in any way detract from its exceptional character. The 45,000 year dating corresponds to a period of cold and dry climate in the Middle Paleolithic. Anthropic indications found on this skull without a mandible suggest hunting practices or the recovery of tusks from a dead animal.

      The skull without its mandible, but especially without its tusks, is neither accidental nor a phenomenon of taphocenosis. The very careful cutting of the alveolar banks that surround the tusks testifies to their intentional recovery. Indeed, the posterior paired parts of the alveoli of the tusks were carefully and deeply cut out so as to be able to recover the ivory teeth in their totality.

      This practice could only have been carried out by hunters or scavengers in two periods: either the individuals were contemporaries or they were post-Neanderthals. In any case, they recovered the tusks from the carcass of the slaughtered or naturally dead animal to transform ivory materials or for any kind of development.

      The most evolved Proboscidians of the genera Elephas and Mammuthus adopt/adopted a horizontal type of dental eruption of the jugal teeth, different from the other groups of the Mammalian class whose vertical eruption first concerns the deciduous teeth, replaced by the permanent teeth. In the woolly mammoth (M. primigenius), whose life expectancy was around 60 years, a second tooth eruption would not have been sufficient during its lifetime and all the teeth would have been worn down to the root, causing a final fall of the last stumps. Only the upper incisors called tusks saw two permanent and milky dentitions. To meet the biological longevity of the Elephantidae,

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