Trigonostoma, Blainville, 1827

Harzhauser, Mathias & Landau, Bernard, 2012, A revision of the Neogene Cancellariid Gastropods of the Paratethys Sea 3472, Zootaxa 3472, pp. 1-71 : 55

Trigonostoma ? boettgeri (Cossmann, 1915)

Discohelix (Pseudomalaxis) calculiformis Boettger, 1906: 138 [non Discohelix calculiformis Dunker, 1847 ].

Pseudomalaxis boettgeri Cossmann, 1915: 143 , pl. 12, figs 22-24.

Pseudomalaxis boettgeri Cossmann — Zilch 1934: 219, pl. 7, fig. 22.

Type material. syntype SMF XII 2375 a, SMF Frankfurt ( Germany), CoŞteiu de Sus ( Romania), Badenian (Middle Miocene) .

Discussion. Boettger (1906) described a juvenile cancellariid from the early Badenian of the Transylvanian Basin as Discohelix calculiformis . This name was preoccupied for a Jurassic species described by Dunker (1847). Therefore, Cossmann (1915) proposed the replacement name Pseudomalaxis boettgeri . The presence of faint columellar folds excludes a placement in the Architectonicidae and consequently Petit & Harasewych (2005) included it in Trigonostoma s.l. The available material does not allow clarifying the status of this species. The characteristic planorbiform early teleoconch is unlike that of any other known species and therefore we consider it a valid species, despite the very juvenile and fragmentary material available.

Distribution. A rare species, which is known so far only from the early Badenian of the Transylvanian Basin and the North Alpine Foreland Basin.

Paratethys —Badenian: Transylvanian Basin ( Romania: CoŞteiu de Sus), North Alpine Foreland Basin ( Austria: Grund; private collection of A. Breitenberger, Austria).