ARGANT Alain

The big cats of the fossil site Château Breccia Northern Section (Saône-et-Loire, Burgundy, France): stratigraphy, palaeoenvironment, ethology and biochronological dating With 13 figs, 7 tabs A b s t r a c t The Château site, known since 1863, was rediscovered in 1968 and new excavations were carried out there between 1997 and 2006. Bear remains largely dominated the Château Breccia fossil assemblage, but the characteristic peculiarity of this site was the abundance of big cats. The old karstic system, including the Château Breccia fossil site, has been completely destroyed, primarily by erosion, but later by quarrying. During the Pleistocene the cave served as hibernation dens for bears. This was most likely also the birthplace for bear cubs. These bear cubs, whether alive or dead, could be a significant source of food for big cats during the winter. The stratigraphy of the infill (Northern Section) reveals successive phases of occupation. The two main fossiliferous layers were labelled Breccia 4 (Br. 4) and Breccia 2 (Br. 2), the former being the earliest. In both cases, we noticed different, though equivalent, animal associations: a bear (Ursus deningeri), a big cat (Panthera gombaszoegensis, Panthera spelaea fossilis), a canid (Canis lupus mosbachensis), and constantly Arvicola cantianus (= A. mosbachensis). Palynological analysis indicates a milieu of moderately cold temperatures for the two breccias. It suggests an open landscape with grassy areas and a forest of pine, fir, oak and other broadleaved trees. Thus far, all attempts to obtain absolute dates for the Northern Section of the site have been unsuccessful: 14 C and thermoluminescence cannot be used, U/Th and Uranium series dating has failed up to now and ESR is not possible because of the absence of herbivore molars with thick enamel. Therefore, only Ursus deningeri, Panthera gombaszoegensis, Panthera spelaea fossilis, lagomorphs and microfauna with Arvicola cantianus biochronologies allow us to suggest an early Middle Pleistocene age for Breccia 4 and a mid Middle Pleistocene age for Breccia 2. The Château Breccia stratigraphy permits biochronologic dating but also the reliable reconstruction of the evolution of two big cats. Panthera gombaszoegensis is found in the Breccia 4 sediments, the oldest from the site. P. spelaea fossilis and P. gombaszoegensis probably coexisted in Breccia 3. Breccia 2 contains only P. spelaea fossilis, which conforms exactly to what is known about its first appearance in Europe.

The Grotte aux Ours of CHÂTEAUBOURG (Ardèche, France): Synthesis on a site discovered 150 years ago

Discovered in 1860 and well known to prehistorians since the end of the 19th century, the Grotte aux Ours of Châteaubourg
was located in a very large quarry which opened on to the Gorges de la Goule, on the right bank of the Rhône River. In July 1995,
quarrying work exposed a pocket of clay and sand. The median layer was very rich in well preserved cave bear (Ursus spelaeus) and
hyena (Crocuta spelaea) bones as well as those of Panthera (Leo) spelaea, Panthera pardus and Canis lupus. They were collected by
B. Gély and G. dal Pra during the course of a salvage excavation carried out with some urgency in 1996. Equus sp. and Capra ibex
were found respectively in layers B1 and B2. flint tools had also been previously collected by several prehistorians. These tools were
very few in number but remarkably homogeneous and relate to a Middle Palaeolithic facies designated as “Micromousterian”.

At present, numerous sites from Europe and Asia have yielded up remains of Panthera gombaszogensis (= gombaszoegensis). It is without doubt the one Felid most similar to Panthera onca but it is an ancestor, not the present day jaguar. Palaeogenetics estimates the divergence between the lion and the jaguar to 2 Myrs. Obviously, jaguars originate from Africa and they spread in Europe between 1.95 et 1.77 Myrs during the time of Olduvai polarity subchron. Recently Hemmer et al. (2010) demonstrated that the semi-mandible of Dmanissi (Georgia) corresponds with a new taxon Panthera onca georgica ssp. nov., the earliest known Asian member of the species. This taxon spread out through Asia and got to  North America during a glacial period between 0.99 and 0.78 Myrs (between the Jaramillo polarity subchron and the end of the Matuyama magnetochron), and finally reached South America not before the Rancholabrean. The Château Breccia (Saône-et-Loire, France) has given an abundant paleontological material of Panthera gombaszogensis (about 400 remains, with a minimum of 6 individuals). It is the mid Middle Pleistocene European form. The pollen analysis indicates temperate climatic conditions but cooler than today and sometimes even quite cold. The landscape was open with grasses spread over the uplands, while woodlands of pine and fir, but also some broadleaved trees were found in the valley. The Château Breccia largely contributes to the story of Panthera gombaszogensis. It demonstrates that the species was  at least adapted to a cold temperate climate and to a biotope highly different from that of the today's jaguar. It shows also the replacement of Panthera gombaszogensis by Panthera spelaea fossilis about 0.6 Myrs ago,  after a period of coexistence of these two Felids.