Two of the authors (A.F. and P.M.) thank Frédéric Lacombat for allowing them to participate in the 5^th International Conference on Mammoths and their relatives at Puy-en-Velay. We thank Louise Byrne for corrections and for reviewing the English version of the manuscript. We would also like to thank all of the people who helped us throughout the field activities. Special thanks to Mr and Mrs Pueo who generously offered the specimen to the Musée des Dinosaures and for allowing us to excavate on their property. Finally, the authors would like to thank P. Tassy and J.-C. Miskovsky, for interesting and constructive comments that contributed to improve the first version of the manuscript.

1 - Introduction

1Discoveries of Mammuthus are common in the south of France in the Pyrenean piedmont especially those of M. primigenius in Upper Pleistocene sequences. Remains attributed to this species have been found as isolated finds (tusks, teeth, and skeletal parts) or more complete animals, which were preserved in alluvial formations or in karstic contexts. Along the Pyrenees, more than fifty sites have yielded Proboscidea remains (more details of these sites and their location in Clot & Duranthon (1990). These sites are essentially located in the central and western parts of the piedmont. They are rare in its oriental part where only four sites yield evidence of the presence of this Proboscidean (fig. 1). Two occurrences come from open-air sites. The first one is located close to Narbonne (Ambert, 1991, Larue, 2001) where the species is not specified but should correspond to M. intermedius or M. trogontherii according to the “Mindel ou Riss ancien” age attributed to the surrounding formation, i.e. Marine Isotopic Stage (MIS) 12 to 8 in Larue (2001). The second one comes from the Tuchan basin, 40 km east of Fourcaud, and was found in association with Coelodonta antiquitatis and attributed to M. primigenius (Casteras et al., 1967). The other two sites are Bize Tournal cave (Bize-Minervois, Aude) and Canecaude cave (Villardonnel, Aude) respectively located 70 km north-east and 50 km north of Fourcaud. Bize Tournal cave yielded four remains of Mammuthus, in the archaeological level F, corresponding to the Aurignacian period (Patou-Mathis, 1994). In Canecaude cave, no Proboscidean remains have been found, but a spear thrower, discovered in a level dated to 14,230 ± 160 BP (Magdalenian), is adorned with a mammoth (Sacchi, 1986). Even though the engraving is not very realistic, the tusks being positioned as if they were horns, this could indicate that mammoths were known in this area during MIS 3 and MIS 2.

2This isolated tusk from the alluviums of the Aude River corresponds to one of the southernmost discoveries of the Mammuthus intermedius-primigenius lineage in the Pyrenees piedmont.

2 - Discovery

3The tusk was discovered at the locality named “la Fourcaud” (42°53’06’’ N and 02°11’45’’ E, altitude ca. 300 m a.s.l.), close to the town of Quillan, during excavation works on privately owned land in July 2010. Further to this discovery, one of us (J.L.L.) was requested to extract the fossil. On July 21^st a team from the Centre Européen de Recherches Préhistoriques (CERP) of Tautavel took part in the excavation of the tusk with the crew from the Musée des Dinosaures. Currently, the tusk is kept in the collections of the Musée des Dinosaures of Espéraza (MDE-M19).

3 - Geological context

4Fourcaud is situated at the end of the first third of the Aude River course, which flows from south to north, drains a mountainous area (Capcir and Corbières) and runs through a narrow valley before slightly widening in the Quillan basin. The Pleistocene formations are not well defined in this area. Some work has been carried out on the Quaternary formations of the lower Aude River and some of its tributaries (Larue, 2001, 2007), but not much on the Quillan basin. Bessière et al. (1989), in the booklet of the Quillan geological map (Crochet et al., 1989), acknowledges that no distinction was made in the chronology of the fluvial deposits, since most of them represent recent sprayings, noted Fz (fig. 2). However, in the older version of the Quillan geological map by Casteras et al. (1967), Fourcaud is situated on the edge of ancient alluvium outcrop, noted a^1e (dotted line superposed on the Crochet et al. map in fig. 2), corresponding, according to the booklet, to a terrace at a relative altitude of 20 to 30 meters above the river.

5The Fourcaud site located ca. 25 m above the present level of the Aude River, corresponds to this higher fluvial terrace. The WNW-ESE topographic profile of the valley (fig. 2 bottom) clearly shows the position of the site on this little terrace preserved to the east of and above the main and more recent alluvial deposits of the Aude.

6At the Fourcaud site, the Albian marls, representing the substratum, are covered by two main Quaternary deposits: ca. 1 m thick alluviums covered by ca. 5 m thick slope deposits (fig. 3). The alluviums begin with a 50 cm thick gravely layer, mainly located to the south of the discovery. These gravels are covered by a 50 cm thick sandy layer including gravel lenses. The tusk was lying above the gravely layer, at the base of the sandy layer. The sand beside the tusk is coarse, well-sorted, and dominated by quartz with fragments of angular to rounded sandstone, limestone, shale and mica. The source material is multiple, as for the Aude river (Bessière et al., 1989). It does not correspond to the alluviums of the Saint-Bertrand stream (fig. 2), as the latter should be made up of highly monotonous deposits, given that the stream only drains Lower Cretaceous black shales (n6b-7a formations on fig. 2). The grading curves of the Fourcaud samples are unimodal, narrow, centered around 650 microns and fairly symmetrical. This well-sorted coarse sand size distribution of grains thus reflects quite a strong aqueous current, but not turbulent.

7According to the local topography and to the relative position of the alluviums above the river level, the terrace does not correspond to the Upper Pleistocene spreading, usually situated around 15 to 20 m above the river level in the region. In the Limoux basin, 25 km downstream from Fourcaud, three main alluvial terraces, Fz, Fy and Fx, have been recognized and distinguished on the geological map (Bessière et al., 1978), situated respectively below 20 m, between 20 and 45 m and between 45 to 80 m above the river level. The Fourcaud terrace can be correlated to the “mid-Quaternary” deposits, i.e. one of the middle terraces recorded between 20 and 30 m above the rivers, and probably to the lower middle terrace. Since the three most recent alluvial deposits correspond to glacial phases in the region (Calvet, 1994), the Fourcaud site may be provisionally correlated to MIS 6 or, less probably MIS 8.

4 - Results

4.1 - Systematics

8Order: Proboscidea Illiger, 1811.

9Family: Elephantidae Gray, 1821.

10Genus: Mammuthus Brookes, 1828.

11Species: Mammuthus intermedius Jourdan, 1861.

4.2 - Description

12The tusk may have been complete but the distal end was broken before we began our excavations and only the proximal end (root) is well preserved. The coloration of the ivory surface is white-grayish, with some oxidation marks on the surface.

13The tusk fragment is approximately 195 cm long along the outside curve and 160 cm along the inside curve. The tusk diameter is approximately 160 mm near the proximal end, and 110 mm near the distal end. The girth measured at the lip is about 50 cm. The specimen exhibits moderate curvature and moderate torsion. The cross section is sub-circular. Significant sexual dimorphism is visible on extant Elephants and Mammuthus tusks. In Elephants, the second upper incisor shows variations in size and curvature based on gender but also during the ontogeny of the animal. In the Mammoth population, female tusks are slender, straight and gracile with a diameter near the root of less than 90 mm whereas male tusks are much larger and more massive with a base diameter close to 200 mm (Averianov, 1996; Haynes, 1991). The diameter and the curvature of the Fourcaud tusk enable us to attribute it to a male animal. The internal coloration is white and although the tusk does not present a perfect transverse section, the Schreger (1800) pattern is clearly visible on the tusk section. The Schreger pattern can be observed from tusks of extant Elephants (Elephas and Loxodonta), and in a wide variety of extinct Proboscideans like Mammuthus, Mammut, Gomphotherium, Anancus and Stegodon (Daubenton, 1754; Owen, 1845; Espinoza & Mann, 1991; Palombo & Villa, 2001; Trapani & Fischer, 2003; Ábelová, 2008). Their tusks consist of a series of dentine cones, radially crossed by bundles of tubules. A tusk cross section, cutting the tubules, produces a pattern (the Schreger pattern) of two sets of lines that radiate clockwise and anticlockwise. They form a characteristic rhomboidal network. Various orientations of tubules can be observed from the tip (apex) to the base (circles with a maximum radius) of the tusk. Therefore, the angle of the rhomboidal structures increases from the center to the periphery of the tusk. The Schreger pattern can be a valid basis for the taxonomic identification of Elephantinae genera, (Espinoza & Mann, 1991; Palombo & Villa, 2001). Schreger angle measurements were carried out on photographs taken perpendicular to the broken transverse sections of the tusk, parallel to the tusk axis.

14In the transverse section, the Fourcaud tusk exhibits a pattern of crossing lines similar to the typical pattern characterizing Mammuthus. The Schreger angle values range from 105-115° with a ‘C’ pattern near the Cement Dentine Junction (CDJ) to 82-96° with a V pattern around 2 cm from the tusk surface. These values are consistent with the values observed for other mammoth tusks (Palombo & Villa, 2001; Trapani & Fischer, 2003; Ábelová, 2008). Due to the wide ranging values of the Schreger angle in this lineage (Palombo & Villa, 2001), the specific attribution must be considered with caution without other more characteristic dental elements such as the last molar (Labe & Guérin, 2005).

4.3 - Taphonomy

15The tusk is not in anatomical connection (not in the cranium alveoli), indicating that the carcass of the mammoth remained exposed to the elements for a long time. Skeletal elements were certainly transported by the current and buried some time after the death of the animal but the tusk was probably not transported by the current over a long distance, given its size and the sedimentological results. The accumulation of gravel on one side of the tusk indicates the direction of the Paleo-Aude current and does not correspond to the weaker competence of the Saint-Bertrand stream. This tusk is the only remain found in the sandy lens; neither the second tusk, nor other skeletal elements of the animal were associated. This depositional environment can transport quite large fresh bones, but seems incompatible with the displacement of a tusk of more than one meter. It is therefore likely that this specimen was deposited above the gravels and covered by sands. This fossil does not seem to be linked to anthropic activity.

5 - Conclusion

16Since the description by Jourdan (1861) of intermediary species between M. trogontherii and M. primigenius, defined from specimens discovered in the Lyon region (France), this taxon had been somewhat forgotten and rarely recognized. During the last decades only Osborn (1942) and Aguirre (1968-1969) identified and validated this taxon. Recently Labe and Guérin (2005) suggested that Mammuthus intermedius was a valid taxon and established a neotype for this species. However, M. intermedius remains have often been described as evolved Mammuthus trogontherii or primitive Mammuthus primigenius (Labe & Guérin, 2005). For Paupe et al. (2010) M. intermedius designates a form ensuring the morphological and temporal transition between M. trongontherii and M. primigenius. The diagnosis of this species is based on the cheek teeth which show an intermediary morphology between M. trogontherii and M. primigenius, a lamellar frequency ranging between 6 and 7.5 and the thickness of the enamel between 1.5 and 2.4 mm on the last molar (Labe & Guérin, 2005). M. intermedius is smaller than M. trogontherii but as big as the largest known M. primigenius, and bears tusks with a more pronounced curvature than the former (Paupe et al., 2010). Most of the material identified as Mammuthus intermedius has been found in sites near Lyon (Labe, 1999; Labe & Guérin, 2005), in the swallow hole of Romain-la-Roche (Paupe et al., 2010), but also in different European countries like Great Britain, Switzerland, Germany, Italy, Hungary and Russia (Aguirre, 1968-1969). The chronology of these sites corresponds to the penultimate glaciation (MIS 6-8), between 300,000 and 130,000 years (Bassinot et al., 1994). M. intermedius is characteristic of the biozone MNQ24 (Guérin, 1980, 1982).

17The analysis of the morphology and the Schreger pattern of the Fourcaud tusk, confirms the attribution of this find to Mammuthus. The identification of a species based on an isolated tusk is not easy. Yet size, shape and curvature of this tusk are closer to later mammoths such as M. trongontherii, M. intermedius and M. primigenius, than earlier ones such as M. meridionalis and allied primitive species. Due to the lack of more characteristic dental and skeletal elements, this tusk is cautiously assigned to Mammuthus cf. intermedius. The main reason is the alleged stratigraphical position. The relative age given for the terrace, where the tusk is embedded is correlated with the penultimate glaciation, corresponding to MIS 6-8. During this period, the great majority of Mammuthus are identified as M. intermedius. Thus, this new discovery is probably the southernmost specimen of Mammuthus intermedius in France, and confirms the large distribution of this taxon.

18The discovery of such mammals in a fluvial context is rare in this part of the Pyrenean massif. This preliminary study will be completed by dating analyses of the tusk, and field surveys, in order to improve our knowledge of the distribution of Quaternary deposits in the Upper Aude Valley.