Eocenochelus farresi, Pérez-García, Adán, Broin, France de Lapparent de & Murelaga, Xabier, 2017

Pérez-García, Adán, Broin, France de Lapparent de & Murelaga, Xabier, 2017, The Erymnochelys group of turtles (Pleurodira, Podocnemididae) in the Eocene of Europe: New taxa and paleobiogeographical implications, Palaeontologia Electronica 15 (2), pp. 1-28 : 15-18

publication ID	https://doi.org/ 10.26879/687
publication LSID	lsid:zoobank.org:pub:1D985176-5AD4-45FF-8BD7-C4AD17C7DE52
persistent identifier	https://treatment.plazi.org/id/03814F39-FFAA-4A22-FC23-E1E3F1088008
treatment provided by	Felipe
scientific name	Eocenochelus farresi
status	sp. nov.

Treatment

Eocenochelus farresi sp. nov.

Figure 8 View FIGURE 8

zoobank.org/ 14C22DFF-85B1-46AF-96BB-BC2AED850248

Holotype. MGSB 74.641 -GLV. T.45, Farrés collection, deposit in Geolab-Vic ( GLV) by delegation of the MGSB. An articulated shell preserving an almost complete plastron and a partial carapace ( Figure 8 View FIGURE 8 ).

Etymology. The specific name is in honor of the geologist Francesc Farrés (GLV, Catalonia, Spain), who discovered and prepared the holotype.

Type locality and horizon. Can Beuloví, Sobremunt, Osona, Barcelona, Catalonia, Spain ( Figure 2 View FIGURE 2 ). Sant Martí Xic Formation, Priabonian, late Eocene ( Sanjuan et al., 2012).

Diagnosis. Member of Eocenochelus with six neurals, resulting in a medial contact between the sixth, seventh and eighth pairs of costals (unique to this species); a well-developed posterior branch of the ischiatic scar present, reaching the short dorsal anal border at the xiphiplastral point (unique to this species); very short epiplastral symphysis, less than one-fifth the length if the entoplastron (unique to this species); intergular triangular, with well-developed, posteriorly convergent lateral margins and an anterior border almost as wide as that of each gular (shared with Eocenochelus lacombianus but not with Eocenochelus eremberti ); long lateral overlap of the humeral scutes onto hyoplastra, the humero-pectoral sulci contacting the middle region of the epiplastral-hyoplastral sutures (unique to this species); slightly convex lateral margins of the posterior plastral lobe (convexity much less developed than in Eo. eremberti , but not convave as in Eo. lacombianus ); deep U-shaped anal notch, being almost as long as wide (unique to this species).

Description. The shell of MGSB 74.641-GLV.T.45 is moderately large and moderately long for its width (the maximum length of the preserved region is about 43 cm, and the maximum width is about 30.5 cm); it was moderately flattened post-mortem. This taxon lacks a medial keel on the carapace ( Figure 8.1-8.2 View FIGURE 8 ). It has six neurals, relatively long for their width. The second to fifth neural elements are hexagonal and longer than wide. Their latero-anterior margins are shorter than their latero-posterior margins. The sixth neural is pentagonal. The plates of the last three pairs of costals are in contact medially. Posterior peripheral points are not present. The third and fourth vertebral scutes are hexagonal. The third one is slightly wider than the fourth. Ventrally, the sixth pair of marginals overlaps the lateral region of the mesoplastra.

The length of the plastron of MGSB 74.641- GLV.T.45 is about 38 cm. The posterior plastral lobe is narrower than the anterior ( Figure 8.3-8.4 View FIGURE 8 ). The anterior lobe is subrounded, lacking gular protrusions and with boadly diverging posterolateral borders that create relatively narrow axillary notches. Its length is equal to half of its width. The epiplastral symphysis is very short, less than one-fifth the length of the entoplastron. The entoplastron is rhomboidal, its latero-anterior margins being longer and straighter than the latero-posterior ones. Along the midline, the hypoplastra are slightly longer than the hyoplastra. The mesoplastra are subrounded, being longer than wide. The lateral margins of the posterior plastral lobe are slightly convex. The anal notch is deep, being almost as long as wide, and U-shaped with subrounded lateral margins. The xiphiplastral extremities are dorsally thickened, widely and longly covered by the ischiatic scar up to the short dorsal border of the anal scute, at the end of the point. The gular scutes are longer than the intergular, with wider anterior margins. Posteriorly, the triangular intergular slightly overlaps the anterior region of the entoplastron. The gulars are medially in contact and medially are as long as the humerals. This specimen shows a large overlap of the latero-posterior region of the humerals onto the hyoplastra. The distance from the pectoro-abdominal sulci to the posterior margin of entoplastron is less than the length of this plate. The femorals overlap onto the hypoplastra, on a scale similar to that of the abdominals. The femoro-anal sulci are located approximately over half of the xiphiplastra length, the anal lateral borders on the xiphiplastra being about 30% longer than the femoral borders. The dorsal expansion of the plastral scute borders is very short.