Rana dalmatina Fitzinger

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 : 24-25

Rana dalmatina Fitzinger in Bonaparte, 1838b Rana cf. dalmatina

Figure 20

Material. Spilia 4: one ilium ( UU SP4 683).

Description.

Te moderately small ilium (UU SP4 683) from Spilia 4 is rather well preserved, even though most of the shaft is missing ( Fig. 20 ). It has a well-developed dorsal crest and a distinct dorsal tubercle. Te tubercle is elongated and shows some low rugosities on its lateral surface. Its dorsalmost point does not exceed the dorsal crest in height. Te dorsal acetabular expansion is moderately long and creates an angle wider than 90° with the tubercle. A small supraacetabular fossa is visible between the tubercle and the dorsal expansion. Te ventral acetabular expansion is rather well developed. Tere is no preacetabular fossa. Te acetabulum is moderately wide. Te medial surface of the body of the ilium does not display any interiliac groove or tubercle. Te bone has a narrow and moderately high ilioischiatic junction.

he did not mention this directly in the text. Similarities between the tubercle of R. dalmatina and the irregular one of R. arvalis are indeed reported, however (Gleed-Owen, 1998, p. 215), maybe involving the morphology of the lateral surface as well. Our personal observations confirm that rugosities are sometimes present on the tubercle of R. dalmatina (AV, pers. obs.), even though this feature appears to be variable. Variation in the roughness/smoothness also occurs in R. temporaria (Gleed-Owen, 1998; AV, pers. obs.). Pending a more complete study of the ilial comparative morphology of brown frogs, we here refer UU SP4 683 to Rana cf. dalmatina , as this species is the one sharing the most similarities with it among the species for which osteological data are available. However, we acknowledge that this identification should only be considered as tentative, awaiting for more information on other species, such as the southern Balkan endemic Rana graeca Boulenger, 1891 .

Remarks. Tis ilium from Spilia 4 is assigned to the genus Rana because of the following features: well-developed dorsal crest; angle between dorsal tubercle and dorsal acetabular expansion higher than 90°; and high and narrow ilioischiatic junction (Bailon, 1999; Gleed-Owen, 1998; Ratnikov, 2001). More than 100 species of Rana are currently recognized (Dubois et al., 2021) and our knowledge of their comparative osteology is extremely limited. Tus, a real identification of this fossil at specific level is not possible, even though some features are useful to discuss. UU SP4 683 differs from Rana temporaria Linnaeus, 1758 , in the well-developed ventral acetabular expansion (Bailon, 1999). A dorsal crest that is higher than the dorsal tubercle is a feature found in Rana dalmatina and Rana iberica Boulenger, 1879 , but not in Rana arvalis Nilsson, 1842 , Rana pyrenaica Serra-Cobo, 1993 , and Rana temporaria (Bailon, 1999; Blain & Arribas, 2017). An irregular lateral surface of the dorsal tubercle is reported for R. arvalis and R. temporaria by Gleed-Owen (1998). Te irregularities seem to be present also in Gleed-Owen’s drawing of the ilium of R. dalmatina (Gleed-Owen, 1998, fig. 5.46a), even though

Figures

Fig. 20 Rana cf. dalmatina from Spilia 4. Right ilium (UU SP4 683) in lateral (a) and medial (b) views