SERPENTES Linnaeus, 1758

Rage, Jean-Claude & Bailon, Salvador, 2005, Amphibians and squamate reptiles from the late early Miocene (MN 4) of Béon 1 (Montréal-du-Gers, southwestern France), Geodiversitas 27 (3), pp. 413-441 : 427

SERPENTES Linnaeus, 1758 Infraorder SCOLECOPHIDIA Duméril & Bibron, 1844

Indeterminate scolecophidian

MATERIAL EXAMINED. — 1 trunk vertebra (Béon 2004 LT 58).

COMMENTS

A tiny, incomplete vertebra represents a scolecophidian (length from prezygapophysis to postzygapophysis: 1.2 mm). It displays a combination of characters that is characteristic of the group: vertebra depressed; long axis of prezygapophyseal facet clearly oriented anteriorly but prezygapophyseal process directed more transversely (as shown by its preserved base); paradi- a p o p h y s e s b l o c k y a n d l a c k i n g a n y t r a c e o f subdivision; posterior median notch in the neural arch absent (inferred from the preserved part of the neural arch).

The vertebral morphology is very homogeneous within the group and identification is impossible, even at family level. Only one extinct species was d e s c r i b e d f r o m E u r o p e: T y p h l o p s g r i v e n s i s Hoffstetter, 1946, from the middle Miocene (MN 7+8) of France; its generic assignment may be questioned ( Rage 1984b).

In Europe, scolecophidians are known from the earliest to the late Eocene ( Crochet et al. 1981; Rage 1984b) but they are lacking in most of the Oligocene. They are again present in the latest Oligocene, at La Colombière, France (MP 30; unpublished). During the Miocene, the group extended from Western to Eastern Europe ( Szyndlar 1985, 1991a; Hír et al. 2001), but during the Pliocene it was restricted to southern Europe, from Spain to Greece ( Bailon 1991; Szyndlar 1991a). In Europe, the only living species inhabits the Balkan and eastern Caucasian regions ( Darevsky 1997).

Infraorder ALETHINOPHIDIA Nopcsa, 1923