The Skull of Quadruped and Bipedal Vertebrates. Djillali Hadjouis

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СКАЧАТЬ 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.

1.3. A young mammoth in Maisons-Alfort

The development operations of the Seine-Marne confluence, which began in the 1980s as part of the Seine-Amont project, have highlighted major sites such as Alfort 1 in Maisons-Alfort, located on the left bank of the Marne, a few hundred meters from its confluence with the Seine. One of the plots excavated in 1995 revealed a Neanderthal occupation of the Middle Paleolithic within the alluvial formations (Durbet et al. 1997). The association of identified animal species (aurochs, bison, red deer, Mosbach horse, wolf, mammoth) and the presence of a lithic industry shaped by Neanderthals allowed the reconstruction of paleoenvironments suggesting a cold and dry glacial climate. Several datings on fossil remains ranging from 160,000 to 200,000 years BCE give an image of a glacial environment in the Paris region inhabited by both humans and animals.

      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).

1.4. A woolly mammoth skull in the reserves

      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.

It was in the 2000s that we studied it, starting with radiocarbon dating. C14 analyses of the radiocarbon laboratory of Villeurbanne gave dates around 45,000 years BCE, the Middle Paleolithic period. Although more recent than the dates of the Middle Paleolithic site of Alfort 1 (190,000 BC), which also yielded mammoth remains, the fact remains that the skull of Bonneuil figures as a spectacular piece within the Quaternary bestiary of Île-de-France. Although it shows traces of anthropic activity that suggest human intervention, there is nothing to distinguish between hunting and natural death. Similarly, the intervention on its carcass must have taken place in two stages after death.

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

1.5. A mammoth skull with removed tusks

      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 morphological criteria found on the maxillary teeth show the typical characters of the woolly mammoth (weak enamel with sinuous sinuses, high hypsodontia index and strongly folded enamel ribbons (Hadjouis 2016b)). The age given to this animal at the time of death is estimated to be between 22 and 34 years. It is based on criteria such as the partial wear of the molars, the clearing of their roots and the absence of wear of the last molar, some of whose distal blade teeth were still embedded in the alveolus. Three jugal teeth were still active on their maxillary medium: the second molars on both sides and the right third molar (Figure 1.2). The two anterior molars were in the process of being replaced.

      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.

Figure 1.2. Lower view of a mammoth skull (Mammuthus primigenius), found in the gravel of Bonneuil Port, showing the replacement of the jugal teeth (© Hadjouis)

1.6. A particular tooth eruption

      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, СКАЧАТЬ