Clausiliidae

Salvador, Rodrigo B., 2014, The fossil land and freshwater snails of Gündlkofen (Middle Miocene, Germany), Zootaxa 3785 (2), pp. 271-287 : 274

Clausiliidae indet.

(Figs. 6–8)

Material examined. BSPG 1952 XVIII 36 (1 spcm.), 37 (6 spcm.).

Previous identification of the material. Gall (1980: Nr. 19 and 20): respectively, Pseudidyla moersingensis (Boettger) and Clausiliidae gen. et sp. indet.

Discussion. Due to the very fragmentary nature of the present specimens, a more precise identification is not feasible. Nevertheless, it should be noted that there are two distinct morphs of spire tops: one larger, with higher whorls (Fig. 6), and one smaller, with the whorls more closely packed together and growing more quickly in width ( Fig. 7). There is also a single apertural fragment ( Fig. 8) that was identified by Gall (1980) as Pseudidyla moersingensis (Boettger) , a species known from the Middle to Late Miocene of Germany ( Nordsieck 1981a, 1982). Its overall shape and dentition seem to indicate the genus Pseudidyla (Boettger 1877), but due to the fragmentary nature of the present specimens, it is impossible to safely assign them to P. moersingensis .

Moreover, Gall (1980: Nr. 18) also lists another clausiliid, Serrulina ptycholarynx (Boettger) , for Gündlkofen; however, as explained above, the lot unfortunately could not be found at the BSPG collection. It should be noted, however, that Nordsieck (1981b) classified Gall’s S. ptycholarynx as a new subspecies, Serrulastra (Serruplica) ptycholarynx galli Nordsieck, and figures the holotype (pl. 8, fig. 18), which consists in a fragmentary body whorl with an intact aperture. The shell sculpture, aperture shape and dentition is congruent with the group of genera Serrulastra Nordsieck, Serrulina Mousson and Serrulella Nordsieck in Zilch. The distinction between these genera, (and their myriad of subgenera, species and subspecies) is very tenuous and classification of fragmentary fossil material is thus further complicated. As such, the validity of this subspecies should be taken carefully.

Finally, the only thing that can be safely said about the clausiliids from Gündlkofen is that they represent two species, one probably belonging to the genus Pseudidyla and the other to Serrulastra or Serrulina and likely the species S. ptycholarynx .

Paleoecological remarks. Nordsieck (2007) suggests that clausiliids up to the Middle Miocene were mostly wood-dwelling animals, preferring humid and warm environments.