Cryptodira Cope, 1868

Georgalis, Georgios L., Villa, Andrea, Ivanov, Martin & Delfino, Massimo, 2024, New diverse amphibian and reptile assemblages from the late Neogene of northern Greece provide novel insights into the emergence of extant herpetofaunas of the southern Balkans, Swiss Journal of Palaeontology (34) 143 (1), pp. 1-91 : 34

Cryptodira Cope, 1868 (sensu Joyce et al., 2020b)

Testudinoidea Fitzinger, 1826 (sensu Joyce et al., 2021)

Emydidae Gray, 1825 (sensu Joyce et al., 2021)

Emys Duméril, 1805

Emys orbicularis (Linnaeus, 1758)

Emys gr. orbicularis

Figure 31

Material. Vevi: a left epiplastron fragment ( UU VE 559), a right hyoplastron fragment ( UU VE 567), a left hypoplastron fragment ( UU VE 560), and a right xiphiplastron fragment ( UU VE 561).

Description.

Te fragmentary left epiplastron UU VE 559 preserves on the external surface only part of the gular-humeral sulcus that does not correspond to a notch at the lateral edge of the bone ( Fig. 31a–d ). On the visceral surface, the preserved portion of the gular pad is low and with a width clearly tapering in medial direction.

Even if only the posterolateral area of the right hyoplastron UU VE 567 is preserved, the axillary buttress is laterally delimited by a relatively smooth area indicating the presence of a ligamental hinge ( Fig. 31e–g ). Te buttress is ventrally marked by the lateral sulcus of the pectoral shield, which is also present at the posterior margin of the element, very close (about 1 mm) to the hyo-hypoplastral contact, represented by a hinge with few large bony interdigitations.

UU VE 560 is a small posterolateral portion of a left hypoplastron ( Fig. 31h–j ), posterior to the abdominalfemoral sulcus that corresponds to the anterior edge of the fragment (only on the dorsal surface of the element there is a very little segment of the sulcus preserved); the dorsal overlap of the femoral shield is wide and slightly broadening posteriorly.

Te right xiphiplastron UU VE 561 preserves only a small portion of the posterolateral region, not including the medial suture but clearly indicating a rather rounded lateral edge of the xiphiplastron and the absence of a deep anal notch ( Fig. 31k–m ). Te area covered by the dorsal overlap of the anal shield is rather tall in the anteriormost-preserved portion and tapers gently in posterior direction.

Remarks. Te most diagnostic element is the fragmentary right hyoplastron UU VE 567 because it shows evidence of a ligamental hinge between the plastron and the carapace as well as between the hyoplastron and the hypoplastron. Among the Neogene European turtles, this morphology univocally characterizes the members of the genus Emys but does not allow discriminating among the few extinct and extant species so far described (see among others: Fritz et al., 2005, 2011; Hervet, 2000; Młynarski, 1956; Ottonello et al., 2021). Te other elements from Vevi are referred to same taxon based on morphological congruence.

Figures

Fig. 31 Emys gr.orbicularis from Vevi.a–d left epiplastron fragment (UU VE 559) in visceral (a), ventral (b), anterolateral (c), and anteromedial (d) views; e–g right hyoplastron fragment (UU VE 567) in visceral (e), ventral (f), and lateral (g) views; h–j left hypoplastron fragment (UU VE 560) in visceral (h), ventral (i), and lateral (j) views; k–m right xiphiplastron fragment (UU VE 561) in visceral (k), ventral (l), and lateral (m) views