taxonID	type	description	language	source
03E187910A227F24AB51FCD4FB08FBFD.taxon	description	(Fig. 1)	en	Lemierre, Alfred, Wilenzik, Ian V., Orliac, Maëva J. (2026): Sneaking past the Grande Coupure: diversity of snakes across the Eocene-Oligocene transition (MP 19 - 22) from Dams (Quercy, southwestern France). Comptes Rendus Palevol 25 (8): 137-154, DOI: 10.5852/cr-palevol2026v25a8, URL: https://doi.org/10.5852/cr-palevol2026v25a8
03E187910A227F24AB51FCD4FB08FBFD.taxon	materials_examined	REFERRED SPECIMENS. — Two trunk vertebrae (UM-DAM 2 - 21 and UM-DAM 2 - 22).	en	Lemierre, Alfred, Wilenzik, Ian V., Orliac, Maëva J. (2026): Sneaking past the Grande Coupure: diversity of snakes across the Eocene-Oligocene transition (MP 19 - 22) from Dams (Quercy, southwestern France). Comptes Rendus Palevol 25 (8): 137-154, DOI: 10.5852/cr-palevol2026v25a8, URL: https://doi.org/10.5852/cr-palevol2026v25a8
03E187910A227F24AB51FCD4FB08FBFD.taxon	description	DESCRIPTION The vertebrae are very small, and nearly equivalent in length and width (Fig. 1 A-E). The neural arch is broad and shallow. The neural spine is low and rounded, with the anterior slope beginning approximately at the posterior margin of the zygosphene (Fig. 1 C). The posterior margin of the neural arch has a shallow medial notch (Fig. 1 D). The centrum features strong interzygapophyseal constriction (Fig. 1 D, E). The cotyle is rounded and similar in size to the neural canal (Fig. 1 A). The prezygapophyses are inclined dorsally and, in an anterior view, are located above the floor of the neural canal (Fig. 1 A). Present also are short prezygapophyseal accessory processes (Fig. 1 D, E). The paradiapophyses form a single articular facet on each side of the vertebrae (Fig. 1 C). No paracotylar foramina are present. The zygosphene has a dorsal bulge in an anterior view (Fig. 1 A). In a dorsal view, the zygosphene margin has three lobes; the medial lobe is rounded and broad and flanked by the two lateral, triangular lobes that extend anteriorly to medial lobe (Fig. 1 D). The condyle is rounded and is as tall and wider than the neural canal (Fig. 1 B). The postzygapophyses terminate at a mediolateral point in the posterior view, giving the postzygapophyses a triangular shape, which falls at approximately the middle of the neural canal (Fig. 1 D). The haemal keel is narrow and poorly defined (Fig. 1 E). ATTRIBUTION These middle trunk vertebrae can be assigned to Platyspondylia based on the following combination of traits: 1) small size; 2) low neural spine; 3) zygosphene with three lobes, one medial and mediolaterally broad and two lateral and mediolaterally narrow; 4) prezygapophyses inclined above the floor of the neural canal in an anterior view; 5) weakly developed prezygapophyseal processes; and 6) paradiapophyses with no subdivisions and that reaches the ventral lip of the cotyle (see Rage 1974; Szyndlar & Rage 2003). Within Platyspondylia, we ascribe this to Platyspondylia sudrei rather than the type species Platyspondylia lepta Rage, 1974, based on the: 1) lower neural arch; and 2) a wider articular surface of the paradiapophyses (see Rage 1974, 1988; Čerňanský et al. 2026). It also differs from the late Oligocene Platyspondylia germanica Szyndlar & Rage, 2003 in having: 1) a convex anterior margin of the zygosphene (straight in P. germanica); and 2) an inclined anterior margin of the neural spine.	en	Lemierre, Alfred, Wilenzik, Ian V., Orliac, Maëva J. (2026): Sneaking past the Grande Coupure: diversity of snakes across the Eocene-Oligocene transition (MP 19 - 22) from Dams (Quercy, southwestern France). Comptes Rendus Palevol 25 (8): 137-154, DOI: 10.5852/cr-palevol2026v25a8, URL: https://doi.org/10.5852/cr-palevol2026v25a8
03E187910A227F25A9B8FB35FE5BFD02.taxon	description	(Fig. 2 A-E)	en	Lemierre, Alfred, Wilenzik, Ian V., Orliac, Maëva J. (2026): Sneaking past the Grande Coupure: diversity of snakes across the Eocene-Oligocene transition (MP 19 - 22) from Dams (Quercy, southwestern France). Comptes Rendus Palevol 25 (8): 137-154, DOI: 10.5852/cr-palevol2026v25a8, URL: https://doi.org/10.5852/cr-palevol2026v25a8
03E187910A227F25A9B8FB35FE5BFD02.taxon	materials_examined	REFERRED SPECIMEN. — One anterior trunk vertebra (UM-DAM 2 - 23).	en	Lemierre, Alfred, Wilenzik, Ian V., Orliac, Maëva J. (2026): Sneaking past the Grande Coupure: diversity of snakes across the Eocene-Oligocene transition (MP 19 - 22) from Dams (Quercy, southwestern France). Comptes Rendus Palevol 25 (8): 137-154, DOI: 10.5852/cr-palevol2026v25a8, URL: https://doi.org/10.5852/cr-palevol2026v25a8
03E187910A227F25A9B8FB35FE5BFD02.taxon	description	DESCRIPTION The vertebra is very small and almost as wide as long (Fig. 2 A-E). The vertebra is from the anterior portion of the vertebral column. The neural arch is depressed (Fig. 2 C), with a low neural spine, extending anteriorly up to the posterior margin of the zygosphene (Fig. 2 C). The posterior margin of the neural arch bears a deep medial notch (Fig. 2 D). The pre- and postzygapophyses have anteroposteriorly elongated articular facets (Fig. 2 D, E), and no prezygapophyseal processes are preserved. The zygosphene anterior margin is thin, straight, and seems to bear two faint lateral lobes (Fig. 2 A). The articular facets of the zygosphene are oriented slightly lateroventrally (Fig. 2 A). The cotyle is circular and smaller than the neural canal (Fig. 2 A). The paradiapophyses are eroded but seem to form a single articular facet on each side (Fig. 2 C). No paracotylar foramina are present (Fig. 2 A). In ventral view, the centrum widens anteriorly (Fig. 2 E). The subcentral ridges are fainted and not well delimited (Fig. 2 E). A small hypapophysis extends posteriorly from the ventral surface of the centrum (Fig. 2 E). ATTRIBUTION This anterior vertebra can be assigned to Eoanilius on the following combination: 1) small size; 2) neural arch depressed, 3) posterior margin of the neural arch notched; 4) small and reduced neural spine; and 5) articular facets of the zygosphene horizontal (see Rage 1974; Szyndlar & Rage 2003). Two species are known for this genus, Eoaniliuseuropae and Eoanilius oligocenicus Szyndlar, 1994 (see Szyndlar & Rage 2003; Smith & Georgalis 2022). Our specimen does resemble Eoanilius europae on the following combination of characters (Rage 1974; Szyndlar 1994; Szyndlar & Rage 2003): 1) small neural spine with poorly defined anterior border; 2) paradiapophyses smaller than in E. oligocenicus (Szyndlar 1994); and 3) bilobed zygosphene (trilobed in E. oligocenicus). However, because anterior trunk vertebrae are not always diagnostic for extinct species, we assign our specimen to Eoanilius aff. europae.	en	Lemierre, Alfred, Wilenzik, Ian V., Orliac, Maëva J. (2026): Sneaking past the Grande Coupure: diversity of snakes across the Eocene-Oligocene transition (MP 19 - 22) from Dams (Quercy, southwestern France). Comptes Rendus Palevol 25 (8): 137-154, DOI: 10.5852/cr-palevol2026v25a8, URL: https://doi.org/10.5852/cr-palevol2026v25a8
03E187910A237F25AB7AFCF4FAB9FABC.taxon	description	(Fig. 2 F-M)	en	Lemierre, Alfred, Wilenzik, Ian V., Orliac, Maëva J. (2026): Sneaking past the Grande Coupure: diversity of snakes across the Eocene-Oligocene transition (MP 19 - 22) from Dams (Quercy, southwestern France). Comptes Rendus Palevol 25 (8): 137-154, DOI: 10.5852/cr-palevol2026v25a8, URL: https://doi.org/10.5852/cr-palevol2026v25a8
03E187910A237F25AB7AFCF4FAB9FABC.taxon	materials_examined	REFERRED MATERIALS. — Two articulated trunk vertebrae (UM-DAM 4 - 51); one trunk vertebra (UM-DAM 4 - 52); one posterior trunk vertebra (UM-DAM 4 - 53).	en	Lemierre, Alfred, Wilenzik, Ian V., Orliac, Maëva J. (2026): Sneaking past the Grande Coupure: diversity of snakes across the Eocene-Oligocene transition (MP 19 - 22) from Dams (Quercy, southwestern France). Comptes Rendus Palevol 25 (8): 137-154, DOI: 10.5852/cr-palevol2026v25a8, URL: https://doi.org/10.5852/cr-palevol2026v25a8
03E187910A237F25AB7AFCF4FAB9FABC.taxon	description	DESCRIPTION Trunk vertebrae The two articulated trunk vertebrae are both small, with the centrum being slightly wider than long (Fig. 2 H, I). The cotyle is much wider than long and is smaller than the neural canal (Fig. 2 F). The neural arch is depressed, with the neural spine forming a low, anteroposteriorly broad arch whose anterior margin reaches the level of the posterior margin of the zygosphene (Fig. 2 G). The posterior margin of the neural arch has a deep, medial notch (Fig. 2 G). The zygosphene is thin and bowed in anterior view with ventro-lateral articular facets (Fig. 2 F). Dorsally, the zygosphene has one mediolaterally broad medial lobe and two mediolaterally narrow lateral lobes that extend anteriorly to the same level as the median lobe (Fig. 2 H). No paracotylar foramen are present (Fig. 2 F). In ventral view, the centrum widens anteriorly (Fig. 2 H). The haemal keel appears poorly delimited (Fig. 2 I). Posterior trunk vertebra This posterior trunk vertebra is small and wider than long (Fig. 2 J-M). In the ventral view, the centrum widens posteriorly (Fig. 2 M). The cotyle is also wider than tall and is smaller than the neural canal (Fig. 2 J). The posteroventral portion of the vertebrae was not preserved, so the condyle is unable to be described properly. The neural arch is depressed, with the neural spine forming a low, broad arch, with a shallow, medial notch at the posterior margin (Fig. 2 L). In the anterior view, the zygosphene is thin and bowed with ventro-lateral articular facets (Fig. 2 J). In the dorsal view, the zygosphene has two lateral, mediolaterally narrow lobes (Fig. 2 L). The prezygapophyses reach dorsally to approximately the midline of the neural canal (Fig. 2 L). The paradiapophyses form a single articular facet on each side of the vertebra (Fig. 2 K). A pair of small paracotylar foramina seems to be visible in anterior view (Fig. 2 J). The haemal keel appears absent. ATTRIBUTION All vertebrae are assigned to Eoanilius on the following characters: 1) small size; 2) neural arch depressed; 3) posterior margin of the neural arch notched; 4) small and reduced neural spine; 5) articular facets of the zygosphene horizontal; and 6) haemal keel poorly defined (Rage 1974; Szyndlar & Rage 2003). Within this genus, our specimens resemble vertebrae of Eoanilius oligocenicus in: 1) having a trilobed zygosphene; 2) large paradiapophyses; and 3) distinct subcentral and lateral foramina (although their presence or absence can be ascribed to fossilization; Rage & Augé 2015). However, the lobes of the zygosphene are more projected anteriorly in E. oligocenicus (see Szyndlar 1994). This difference has been noticed in vertebrae from the coeval locality in Valbro (Rage & Augé 2015), and the significance of this difference is currently unknown. The presence of paracotylar foramina in UM-DAM 4 - 53 deserves a comment. Presence of this feature has never been, to our knowledge, documented within any illustrated vertebrae assigned to Eoanilius (e. g., Rage 1974; Szyndlar 1994; Rage & Augé 2015), and could point either to a distinct taxon, or to a larger intrageneric diversity. Because the specimen is not well preserved, and because other foramina within Eoanilius are known to be depended on fossilization (Rage & Augé 2015), we consider UM-DAM 4 - 53 does not represent a distinct taxon. Thus, we assign our three specimens to Eoanilius aff. oligocenicus, acknowledging the close resemblance to the morphology of this taxon.	en	Lemierre, Alfred, Wilenzik, Ian V., Orliac, Maëva J. (2026): Sneaking past the Grande Coupure: diversity of snakes across the Eocene-Oligocene transition (MP 19 - 22) from Dams (Quercy, southwestern France). Comptes Rendus Palevol 25 (8): 137-154, DOI: 10.5852/cr-palevol2026v25a8, URL: https://doi.org/10.5852/cr-palevol2026v25a8
03E187910A237F28A9E6FA12FB5AFC1D.taxon	description	(Fig. 3 A)	en	Lemierre, Alfred, Wilenzik, Ian V., Orliac, Maëva J. (2026): Sneaking past the Grande Coupure: diversity of snakes across the Eocene-Oligocene transition (MP 19 - 22) from Dams (Quercy, southwestern France). Comptes Rendus Palevol 25 (8): 137-154, DOI: 10.5852/cr-palevol2026v25a8, URL: https://doi.org/10.5852/cr-palevol2026v25a8
03E187910A237F28A9E6FA12FB5AFC1D.taxon	materials_examined	REFERRED MATERIALS. — Two trunk vertebrae (UM-DAM 4 - 55 and UM-DAM 4 - 62).	en	Lemierre, Alfred, Wilenzik, Ian V., Orliac, Maëva J. (2026): Sneaking past the Grande Coupure: diversity of snakes across the Eocene-Oligocene transition (MP 19 - 22) from Dams (Quercy, southwestern France). Comptes Rendus Palevol 25 (8): 137-154, DOI: 10.5852/cr-palevol2026v25a8, URL: https://doi.org/10.5852/cr-palevol2026v25a8
03E187910A237F28A9E6FA12FB5AFC1D.taxon	description	DESCRIPTION This trunk vertebra is small with a centrum as wide as long, without anterior widening (anterior and posterior margins being relatively the same width; Fig. 3 A, B). The cotyle is circular and larger than the neural canal (Fig. 3 A 1). The neural spine is short low, reduced posteriorly (Fig. 3 A 2, B 1). The neural arch is not vaulted. The zygosphene is bowed in anterior view but is missing its median part (Fig. 3 A 1, B 1). As such, we have no indication if the zygosphene was trilobed (lateral lobes are present; Fig. 3 A 2). In ventral view, the haemal keel is narrow but delimited by marked subcentral margins (Fig. 3 A 3, B 2). The prezygapophyses are small and markedly expanded anterolaterally (Fig. 3 A 2, B 1). ATTRIBUTION This unnamed form represented by UM-DAM 4 - 55 differs from Eoanilius aff. oligocenicus in having: 1) a narrow haemal keel; 2) well delimited subcentral margins; and 3) circular cotyle and condyle. As such, they represent a second distinct alethinophidian taxon from the Oligocene assemblage of Dams. It does differ from Platyspondylia in having well delimited subcentral margins and circular cotyle and condyle. It also differs from the Oligocene Falseryx neervelpensis Szyndlar, Smith & Rage, 2008 in: 1) having a smaller neural spine; and 2) lacking prezygapophyseal accessory processes. Thus, it likely represents a distinct unnamed taxon from the Oligocene, here informally referred as ‘ Alethinophidia indet. morphotype 1 ’. ‘ Alethinophidia indet. morphotype 2 ’ (Fig. 3 B)	en	Lemierre, Alfred, Wilenzik, Ian V., Orliac, Maëva J. (2026): Sneaking past the Grande Coupure: diversity of snakes across the Eocene-Oligocene transition (MP 19 - 22) from Dams (Quercy, southwestern France). Comptes Rendus Palevol 25 (8): 137-154, DOI: 10.5852/cr-palevol2026v25a8, URL: https://doi.org/10.5852/cr-palevol2026v25a8
03E187910A237F28A9E6FA12FB5AFC1D.taxon	materials_examined	REFERRED MATERIAL. — One trunk vertebra (UM-DAM 4 - 62).	en	Lemierre, Alfred, Wilenzik, Ian V., Orliac, Maëva J. (2026): Sneaking past the Grande Coupure: diversity of snakes across the Eocene-Oligocene transition (MP 19 - 22) from Dams (Quercy, southwestern France). Comptes Rendus Palevol 25 (8): 137-154, DOI: 10.5852/cr-palevol2026v25a8, URL: https://doi.org/10.5852/cr-palevol2026v25a8
03E187910A237F28A9E6FA12FB5AFC1D.taxon	description	DESCRIPTION This trunk vertebra is small and poorly preserved (Fig. 3 B). The centrum slightly widens anteriorly (Fig. 3 B 2). The neural spine is reduced to a small tubercle on the posterior region of the neural arch (Fig. 3 B 1). The prezygapophysis is elongated anterolaterally but small (Fig. 3 B 1). The haemal keel is well-delimited by subcentral ridges (Fig. 3 B 2). ATTRIBUTION This vertebra is poorly preserved. It does differ from Eoanilius aff. oligocenicus and Platyspondylia in having well-delimited subcentral ridges. It does also differ from Falseryx neervelpensis in having a very small and reduced neural spine. It seems to differ from the ‘ Alethinophidia indet. morphotype 1 ’ in having a wider haemal keel and would represent a second alethinophidian morphotype, here referred as ‘ Alethinophidia indet. morphotype 2 ’. However, because UM-DAM 4 - 62 is poorly preserved, it is difficult to assess if it represents a distinct taxon from the ‘ Alethinophidia indet. morphotype 1 ’ or whether the differences can simply be attributed to intracolumnar variation. ‘ Alethinophidia indet. morphotype 3 ’ (Fig. 3 C-E)	en	Lemierre, Alfred, Wilenzik, Ian V., Orliac, Maëva J. (2026): Sneaking past the Grande Coupure: diversity of snakes across the Eocene-Oligocene transition (MP 19 - 22) from Dams (Quercy, southwestern France). Comptes Rendus Palevol 25 (8): 137-154, DOI: 10.5852/cr-palevol2026v25a8, URL: https://doi.org/10.5852/cr-palevol2026v25a8
03E187910A237F28A9E6FA12FB5AFC1D.taxon	materials_examined	REFERRED MATERIALS. — Three trunk vertebrae (UM-DAM 4 - 56, 58, 59).	en	Lemierre, Alfred, Wilenzik, Ian V., Orliac, Maëva J. (2026): Sneaking past the Grande Coupure: diversity of snakes across the Eocene-Oligocene transition (MP 19 - 22) from Dams (Quercy, southwestern France). Comptes Rendus Palevol 25 (8): 137-154, DOI: 10.5852/cr-palevol2026v25a8, URL: https://doi.org/10.5852/cr-palevol2026v25a8
03E187910A237F28A9E6FA12FB5AFC1D.taxon	description	DESCRIPTION These three trunk vertebrae (UM-DAM 4 - 56, 58, 59; Fig. 3 C-E). They differ from those assigned to ‘ Alethinophidia indet. morphotypes 1 and 2 ’ in: 1) being larger; 2) having the lateral lobes of the zygosphene anteroposteriorly expanded to form lateral ridges (Fig. 3 C 2, D 2, E 2); 3) having the articular facets of the prezygapophyses expanded anterolaterally (rhomboidal shaped structure); 4) having a neural spine extending more anteriorly; and 5) having a more developed neural spine (Fig. 3 C 4, E 4). ATTRIBUTION As mentioned above, these vertebrae differ from the one assigned to the ‘ Alethinophidia indet. morphotype 1 ’ and the ‘ Alethinophidia indet. morphotype 2 ’, They also differ from Eoanilius in: 1) having a more developed median lobe on the zygosphene; and 2) having a neural spine more extended anteroposteriorly and more developed dorsally. Hence, it represents a third Oligocene alethinophidian morphotype from the Oligocene of Dams. This species does resemble Falseryx neervelpensis, in: 1) having distinct prezygapophyseal accessory processes; and 2) well developed lateral lobes and trilobed condition on the zygosphene (Szyndlar et al. 2008). However, it differs in: 1) having a more developed neural spine and a more distinct central lobe on the zygosphene; and 2) lacking the prezygapophyseal buttresses developed into prominent tubercles. This Oligocene taxon also differs from Platyspondylia in having a more anteroposteriorly developed and taller neural spine. Thus, it likely represents a distinct unnamed taxon from the Oligocene, here informally referred as ‘ Alethinophidia indet. morphotype 3 ’. Alethinophidia indet. (Fig. 3 F-K)	en	Lemierre, Alfred, Wilenzik, Ian V., Orliac, Maëva J. (2026): Sneaking past the Grande Coupure: diversity of snakes across the Eocene-Oligocene transition (MP 19 - 22) from Dams (Quercy, southwestern France). Comptes Rendus Palevol 25 (8): 137-154, DOI: 10.5852/cr-palevol2026v25a8, URL: https://doi.org/10.5852/cr-palevol2026v25a8
03E187910A237F28A9E6FA12FB5AFC1D.taxon	materials_examined	REFERRED MATERIAL. — One incomplete left maxilla (UM-DAM 4 - 54); three trunk vertebrae (UM-DAM 4 - 57, UM-DAM 4 - 60, and UM-DAM 4 - 61); two articulated trunk vertebrae (UM-DAM 4 - 63); one cloacal vertebra (UM-DAM 4 - 64).	en	Lemierre, Alfred, Wilenzik, Ian V., Orliac, Maëva J. (2026): Sneaking past the Grande Coupure: diversity of snakes across the Eocene-Oligocene transition (MP 19 - 22) from Dams (Quercy, southwestern France). Comptes Rendus Palevol 25 (8): 137-154, DOI: 10.5852/cr-palevol2026v25a8, URL: https://doi.org/10.5852/cr-palevol2026v25a8
03E187910A237F28A9E6FA12FB5AFC1D.taxon	description	DESCRIPTION Maxilla UM-DAM 4 - 54 is small, and only the anterior portion of the bone is preserved (Fig. 3 F). It preserves one recurved tooth at the most anterior tooth position, along with two tooth positions without teeth preserved; the empty sockets are angled anteroventrally (Fig. 3 F 3). The anterior most tooth extends anteriorly exactly with the anterior boundary of the maxilla (Fig. 3 F) and has been rounded due to weathering. Trunk vertebrae Four specimens (UM-DAM 4 - 57, 60, 61, 63; Fig. 3 G-I) of trunk vertebrae that cannot be assigned to any of the three identified alethinophidians. Three of them (UM-DAM 4 - 60, 61, 63) differ from the two unnamed alethinophidians in: 1) having a haemal keel poorly defined; and 2) having a dorsoventrally compressed cotyle. It can be further differentiated from the ‘ unnamed alethinophidian 1 ’ in being narrower. It can also be differentiated from the ’ unnamed alethinophidian 2 ’ in: 1) having a very reduced neural spine; and 2) small zygapophyses (Fig. 3 G 2, H 2). The fourth vertebra, UM-DAM 4 - 57, has a centrum wider than long (Fig. 3 J 3). The cotyle is slightly elongated, wider than tall, and approximately the same size as the neural canal (Fig. 3 J 1). In the anterior view, the zygosphene is bowed (Fig. 3 J 1) with no lobes in the dorsal view (Fig. 3 J 2). The prezygapophyses are oriented dorsolaterally, although the apices are weathered. The paradiapophyses form a large, deep single articular facet on the side of the vertebra (Fig. 3 J 4). There are also no paracotylar foramina. The interzygapophyseal ridge is well-defined (Fig. 3 J 4). The neural spine is anteroposteriorly extended, with a deep notch on the posterior margin (Fig. 3 J 2). The condyle is weathered but maintains a rounded shape and not well-differentiated from the centrum (Fig. 3 J 3, J 4). The haemal keel is low, broad, and rounded (Fig. 3 J 3). Cloacal vertebra The vertebra (UM-DAM 4 - 64) is small, with a centrum that is longer than wide (Fig. 3 K). The cotyle is rounded, slightly wider than tall, and larger than the neural canal (Fig. 3 K 1). In the anterior view, the zygosphene is thick and the dorsal margin forms a flat, horizontal surface (Fig. 3 K 1). In dorsal view, the zygosphene has two, very small and pointed lateral lobes (Fig. 3 K 2). The prezygapophyses are oriented laterally, forming a horizontal dorsal margin (Fig. 3 K 2). The paradiapophyses form a large, deep single articular facet on the side of the vertebrae (Fig. 3 K 4). The neural spine is tall, forming a broad ridge that starts anteriorly at the approximate posterior margin of the prezygapophysis (Fig. 3 K 2, K 4). The anterior margin of the neural spine is flat and posterio-distally oriented, and the posterior margin is dorsally convex (Fig. 3 K 4). The neural spine also has a small notch on the posterior aspect (Fig. 3 K 2). The haemal keel is deep and mediolaterally broad, located on the posterior portion of the centrum closer to the condyle (Fig. 3 K 3, K 4). The condyle is round and well-differentiated from the centrum (Fig. 3 K 3). ATTRIBUTION The maxilla can be assigned to Alethinophidia based on its dentition, made of subthecodont teeth, the latter curved posteriorly in a “ hook ” shape (Georgalis et al. 2021). It cannot be assigned more precisely among snakes. Three trunk vertebrae (UM-DAM 4 - 60, 61, 63) are similar to vertebrae assigned to Eoanilius in: 1) having a poorly defined haemal keel; 2) very reduced neural spine; 3) small zygapophyses; and 4) dorsoventrally compressed cotyle (Fig. 3 G-I). However, they are too poorly preserved, especially in the zygosphene region, to be assigned to Eoanilius with certainty. UM-DAM 4 - 57, 64 are too poorly preserved to allow comparisons.	en	Lemierre, Alfred, Wilenzik, Ian V., Orliac, Maëva J. (2026): Sneaking past the Grande Coupure: diversity of snakes across the Eocene-Oligocene transition (MP 19 - 22) from Dams (Quercy, southwestern France). Comptes Rendus Palevol 25 (8): 137-154, DOI: 10.5852/cr-palevol2026v25a8, URL: https://doi.org/10.5852/cr-palevol2026v25a8
03E187910A2F7F2AA9C0F913FEC7F81E.taxon	description	(Fig. 5)	en	Lemierre, Alfred, Wilenzik, Ian V., Orliac, Maëva J. (2026): Sneaking past the Grande Coupure: diversity of snakes across the Eocene-Oligocene transition (MP 19 - 22) from Dams (Quercy, southwestern France). Comptes Rendus Palevol 25 (8): 137-154, DOI: 10.5852/cr-palevol2026v25a8, URL: https://doi.org/10.5852/cr-palevol2026v25a8
03E187910A2F7F2AA9C0F913FEC7F81E.taxon	materials_examined	REFERRED SPECIMENS. — Four trunk vertebrae (UM-DAM 4 - 65 – UM-DAM 4 - 68).	en	Lemierre, Alfred, Wilenzik, Ian V., Orliac, Maëva J. (2026): Sneaking past the Grande Coupure: diversity of snakes across the Eocene-Oligocene transition (MP 19 - 22) from Dams (Quercy, southwestern France). Comptes Rendus Palevol 25 (8): 137-154, DOI: 10.5852/cr-palevol2026v25a8, URL: https://doi.org/10.5852/cr-palevol2026v25a8
03E187910A2F7F2AA9C0F913FEC7F81E.taxon	description	DESCRIPTION All four vertebrae are relatively large, with relatively equal length and width. The cotyle is slightly wider than tall and is larger than the neural canal (Fig. 5 D, H). No paracotylar foramen are present. In the anterior view, the zygosphene is horizontal and thick, with articular facets oriented ventrolaterally (Fig. 5 A, E). Dorsally, the zygosphene is trilobed, with two mediolaterally narrow lateral lobes and one mediolaterally broad medial lobe (Fig. 5 C, G). The prezygapophyses are elongate and dorsolaterally oriented (Fig. 5 C, G). The paradiapophyses form a single articular facet, with projections extending further ventrally than the ventral margin of cotyle (Fig. 5 A, I). The neural spine is thick, anteroposteriorly broad, and dorsally flat. The most dorsal portion of the neural spine forms a shelf (Fig. 5 C, G, I). The posterior edge of the neural spine overhangs the posterior margin of the centrum. The condyle is slightly mediolaterally elongated and well-differentiated from the rest of the centrum (Fig. 5 D, H). The postzygapophyses are horizontally oriented and taper to a point laterally (Fig. 5 C). The haemal keel is shallow and not well-defined and is shaped like a biconcave lens (Fig. 5 D, H). ATTRIBUTION We attribute these vertebrae to Oligocene Bavarioboa based on: 1) a straight zygosphene in anterior view; 2), prezygapophyses located above the ventral margin of the neural canal; and 3) paradiapophyses that project ventrally beyond the ventral margin of the cotyle (see Szyndlar & Rage 2003). Among known Bavarioboa species, all our vertebrae resemble Bavarioboa crocheti in: 1) having a trilobed zygosphene (sharing with coeval Bavarioboa vaylatsae Szyndlar & Rage, 2003); 2), a haemal keel shaped like a biconcave lens (shared with Bavarioboa hermi Szyndlar & Schleich, 1993 and Bavarioboa herrlingensis Szyndlar & Rage, 2003); and 3) thickened neural spines (see Szyndlar & Rage 2003). Hence, all vertebrae from DAM 4 are assigned to Bavarioboa crocheti.	en	Lemierre, Alfred, Wilenzik, Ian V., Orliac, Maëva J. (2026): Sneaking past the Grande Coupure: diversity of snakes across the Eocene-Oligocene transition (MP 19 - 22) from Dams (Quercy, southwestern France). Comptes Rendus Palevol 25 (8): 137-154, DOI: 10.5852/cr-palevol2026v25a8, URL: https://doi.org/10.5852/cr-palevol2026v25a8
03E187910A2C7F2BA93EFB94FCA3FA5C.taxon	description	(Fig. 6 A-D)	en	Lemierre, Alfred, Wilenzik, Ian V., Orliac, Maëva J. (2026): Sneaking past the Grande Coupure: diversity of snakes across the Eocene-Oligocene transition (MP 19 - 22) from Dams (Quercy, southwestern France). Comptes Rendus Palevol 25 (8): 137-154, DOI: 10.5852/cr-palevol2026v25a8, URL: https://doi.org/10.5852/cr-palevol2026v25a8
03E187910A2C7F2BA93EFB94FCA3FA5C.taxon	materials_examined	REFERRED SPECIMENS. — Two trunk vertebrae (UM-DAM 2 - 19 and UM-DAM 2 - 20).	en	Lemierre, Alfred, Wilenzik, Ian V., Orliac, Maëva J. (2026): Sneaking past the Grande Coupure: diversity of snakes across the Eocene-Oligocene transition (MP 19 - 22) from Dams (Quercy, southwestern France). Comptes Rendus Palevol 25 (8): 137-154, DOI: 10.5852/cr-palevol2026v25a8, URL: https://doi.org/10.5852/cr-palevol2026v25a8
03E187910A2C7F2BA93EFB94FCA3FA5C.taxon	description	DESCRIPTION The description is based on UM-DAM 2 - 19, the most complete vertebra. The vertebra is wider than long. The vertebra is slightly deformed, with the condyle not aligned with the anteroposterior axis of the centrum (Fig. 6 A). The cotyle is ovoid, wider than long (Fig. 6 A). The vertebral canal is rhombohedral-shaped and narrows dorsally (Fig. 6 A). The zygosphene is as wide as the cotyle. Its articular facets are lateroventrally oriented. The zygosphene is moderately thick and slightly arched in anterior view (Fig. 6 A, C). It is trilobed, with a prominent median lobe. The neural arch is vaulted. The neural spine is broken near its base, assessing its height is not possible (Fig. 6 B). However, it is oriented posteriorly and likely extended past the postzygapophyses. The prezygapophyses bear ovoid articular facet oriented dorsally. They bear small prezygapophyseal processes. The interzygapophyseal ridge is well-marked laterally (Fig. 6 B). It extends as a small lateral blade. The synapophyses are weakly divided between dia- and parapophysis. No paracotylar foramen is present. However, the diapophysis is larger and wider than the parapophysis. In ventral view, the centrum is clearly triangular shaped, with a wider anterior region. The haemal keel is thin, but not well-marked (Fig. 6 D). The subcentral ridges are present but faint (Fig. 6 D). ATTRIBUTION Both vertebrae are referred to Constrictores on: 1) the presence of a centrum wider than longer, triangular shaped (i. e., widening anteriorly; Fig. 6 D); 2) small prezygapophyseal accessory processes; 3) parapophyses faintly divided into two articular facets; and 4) no paracotylar foramen (Fig. 6 A-D). Furthermore, our vertebrae are referred to “ Palaeopython ” neglectus as: 1) symmetrical interzygapophyseal constriction (asymmetrical in Palaeopython); 2) thinner zygosphene than Palaeopython and Phosphoroboa Georgalis, Rabi & Smith, 2021; and 3) neural spine extending anteriorly onto the zygosphene roof (Fig. 6 C; see Georgalis et al. 2021). It should be noted that the assignment of this species to the genus Palaeopython is doubtful, and will likely be revised when more available material, in particular cranial remains, will be described (Georgalis et al. 2021).	en	Lemierre, Alfred, Wilenzik, Ian V., Orliac, Maëva J. (2026): Sneaking past the Grande Coupure: diversity of snakes across the Eocene-Oligocene transition (MP 19 - 22) from Dams (Quercy, southwestern France). Comptes Rendus Palevol 25 (8): 137-154, DOI: 10.5852/cr-palevol2026v25a8, URL: https://doi.org/10.5852/cr-palevol2026v25a8
03E187910A2A7F2EA9BBFA35FCA0FA1C.taxon	description	(Fig. 8)	en	Lemierre, Alfred, Wilenzik, Ian V., Orliac, Maëva J. (2026): Sneaking past the Grande Coupure: diversity of snakes across the Eocene-Oligocene transition (MP 19 - 22) from Dams (Quercy, southwestern France). Comptes Rendus Palevol 25 (8): 137-154, DOI: 10.5852/cr-palevol2026v25a8, URL: https://doi.org/10.5852/cr-palevol2026v25a8
03E187910A2A7F2EA9BBFA35FCA0FA1C.taxon	materials_examined	REFERRED SPECIMENS. — Five trunk vertebrae (UM-DAM 4 - 74 – UM-DAM 4 - 78); two cloacal vertebrae (UM-DAM 4 - 79 and 80).	en	Lemierre, Alfred, Wilenzik, Ian V., Orliac, Maëva J. (2026): Sneaking past the Grande Coupure: diversity of snakes across the Eocene-Oligocene transition (MP 19 - 22) from Dams (Quercy, southwestern France). Comptes Rendus Palevol 25 (8): 137-154, DOI: 10.5852/cr-palevol2026v25a8, URL: https://doi.org/10.5852/cr-palevol2026v25a8
03E187910A2A7F2EA9BBFA35FCA0FA1C.taxon	description	DESCRIPTION Most vertebrae are complete. The centrum is elongated anteroposteriorly. It bears a small and circular cotyle (Fig. 8 A, B). The vertebral canal is rhombohedral and wider than the cotyle (Fig. 8 A). A small paracotylar foramen is present (Fig. 8 A). The zygosphene is thin and flat. Its articular facets are slightly ventrolaterally oriented. In dorsal view, the zygosphene does not bear any lobes, safe for a small anterior projection of its articular facets (Fig. 8 A, D). The prezygapophyses bear dorsally oriented articular facets. These facets are ovoid and bear a prezygapophyseal process anteriorly (Fig. 8 A, E). The neural arch is not vaulted. The neural spine extends from the zygosphene to the posterior margin of the neural arch. The spine is developed as a blade-like structure, with the same height throughout its whole length (Fig. 8 B-D). The dia- and parapophyses are small. Although closely spaced together, they form two distinct articular facets (Fig. 8 C). In posterior view, the zygantrum is shallow. In ventral view, the centrum is slightly triangular-shaped (Fig. 8 E). The subcentral ridges are thin. The haemal keel is thin but strongly projected ventrally, forming a blade-like structure. ATTRIBUTION The presence of: 1) a centrum anteroposteriorly elongated; 2) a neural spine well-developed and blade-like; and 3) a haemal keel well-developed and blade-like is diagnostic for caenophidian snakes that have not continuous hypapophysis across their trunk vertebrae (Zaher et al. 2019). Among them, only “ Coluber ” cadurci Rage, 1974 is known within the Oligocene of the Quercy (Rage 2006; Smith & Georgalis 2022). Our vertebrae resemble those of “ Coluber ” cadurci (Rage, 1974) in: 1) having a neural spine extending on the entire length of the neural arch; and 2) having a blade-like haemal keel. However, because prezygapophyseal accessory processes are not complete (long prezygapophyseal processes are part of “ Coluber ” cadurci diagnosis; Rage, 1974), they are tentatively assigned to “ Coluber ” cf. cadurci. Note that the genus level placement of this taxon is still far from resolved we follow previous authors (e. g., Smith & Georgalis 2022) in only tentatively including it in the wastebasket genus Coluber.	en	Lemierre, Alfred, Wilenzik, Ian V., Orliac, Maëva J. (2026): Sneaking past the Grande Coupure: diversity of snakes across the Eocene-Oligocene transition (MP 19 - 22) from Dams (Quercy, southwestern France). Comptes Rendus Palevol 25 (8): 137-154, DOI: 10.5852/cr-palevol2026v25a8, URL: https://doi.org/10.5852/cr-palevol2026v25a8
