A propos de l'Eusmilus (Eusmilus bidentatus ringeadei Ringeade et Michel, 1994) de Soumailles, lieu-dit de la commune de Pardaillan, Canton de Duras (Lot et Garonne, France) : étude descriptive - article ; n°1 ; vol.6, pg 5-37

Michel Ringeade, Patrick Michel

Description

Paléo - Année 1994 - Volume 6 - Numéro 1 - Pages 5-37
The well known site of Soumailles (Richard, 1946 ; Ringeade, 1967a and b, 1987) (a place near Pardaillan in Lot-et-Garonne, France) is stratigraphically situated just above the Grande Coupure of Sthelin (1909), at the base of the Lower Oligocene. The parts studied in this work from the almost complete skeleton belong to the genus Eusmilus (Carnivora Feliformia, Feloidea, Nimravidae - Martin, 1989 ; Wozencraft 1989 a and b-) which is one of the leaders of a new migration in Europe at that time. This Eusmilus from Soumailles is the oldest known in Europe for the genus. It presents many characters less progressive than the Eusmilus bidentatus from Villebramar (Brunet, 1972, 1979) or the Phosphorites ot Quercy (Piveteau, 1932) as well as the Eusmilus sicanus from North America (Scott and Jepsen, 1936). The Eusmilus from the Eocene of Lushih (Chow, 1958) is more primitive than the one from Soumailles and that seems to confirm the asiatic origin for the group. For these différents reasons and in wiew of its great stratigraphical age this specimen was attributed to a new subspecies : Eusmilus bidentatus ringeadei (Ringeade and Michel, 1994). Diagnosis : In order to simplify the Systematic classification we are keeping the bidentatus species name even though the Eusmilus from Soumailles has three upper incisors and three lower incisors. In comparison with the European Eusmilus, the specimen from Soumailles has : - a skull with a longer face and a foramen magnum placed higher, - a lower jaw with a flange process less high and not as short a massetenc fossa towards the front. Dentition : 3/3 I, 1/1 C, 3/1 P. 1/1 M Tree upper incisors and three lower incisors, upper canines smaller, narrower in the antero-posteriorly sense and less curved than those of the Eusmilus bidentatus from Villebramar or the Phosphorites of Quercy, there is an atrophied P2 (a lacteal tooth which could be present during all the animal's life time) The lower canine fang does not look like an 13. The Eusmilus from Soumailles is more plantigrade or less fleet of foot than all the actual big cats with retractiles claws. Type : An almost complete skeleton (vertebral column, ribs, fore and hind limbs) in anatomic order, with also : - One anterior fragment of a skull with right II, 12. 13. C. P2, P3, left alveoli of 12. 13. C. P2 and the left P3. - Posterior fragment of a skull, right P4 ; right lower jaw (with II, 12, 13, C, P4 et Ml ) and left lower jaw (with II, 12, 13 et C) ; -and, fragments of the left lower jaw with Ml and P4 ; Denvatio nominis : named Eusmilus bidentatus ringeadei nov. ssp. in homage to Mister Ringeade who excavated the site of Soumailles and discovered this Nimravidae. Locus typicus Soumailles (Lot-et-Garonne, France) stratigraphically situated just above the Grande coupure at the base of the Lower Oligocene (MP 21).
Du célèbre gisement de Soumailles (Lot et Garonne - France) stratigraphiquement situé au-dessus de la grande coupure de Stehlin (base de l'Oligocène inférieur - MP 21) provient, de fouilles effectuées par M. Ringeade, un magnifique squelette quasi-complet, en connexion anatomique, d'un Feloidea du Genre Eusmilus. De par sa position stratigraphique et de par ses particularités morphologiques (moins progressif que les Eusmilus bidentatus des Phosphorites du Quercy ou de Villebramar) nous l'avons attribué à une nouvelle sous-espèce, à savoir Eusmilus bidentatus ringeadei.
33 pages
Source : Persée ; Ministère de la jeunesse, de l’éducation nationale et de la recherche, Direction de l’enseignement supérieur, Sous-direction des bibliothèques et de la documentation.

Sujets

• Sciences et techniques

Informations

• Publié par: PALEORIENT
• Publié le: 01 janvier 1994
• Nombre de lectures: 13
• Langue: Français
• Poids de l'ouvrage: 4 Mo

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