Csigabaga, Szabó, 2018

Szabó, János, 2018, Gastropods of the Lower Jurassic Hierlatz Limestone Formation, part 4. New eucycloidean, trochoidean, neritimorph, and caenogastropod taxa in the fauna of the Hierlatz Alpe (Hallstatt, Austria), Fragmenta Palaeontologica Hungarica 35, pp. 61-84 : 74-75

Csigabaga n. gen.

Type species – Csigabaga nillae n. sp.

Derivation of name – Csiga (Hungarian) = snail; csiga-biga = snail in children’s language; Csigabaga = the first pronunciation from Nilla, baby granddaughter of the author. The species name is dedicated also to her.

Diagnosis – Slightly cyrtoconoidal, anomphalous shell with obliquely flattened latest base and abaxially extending last whorl near peristome. Apex blunt, protoconch depressed, almost planispiral. Whorls low, their number about eight in full grown stage. Whorl surface convex and suture impressed in earliest shell parts then gradually changing into flush. Last half whorl becoming convex again. Wall of base also convex but flattened on last half whorl. Last peristome having strongly thickened, lunuliform inner lip, with wide outer face. Marked, short columellar fold at middle of columellar lip, significantly narrowing aperture. Outer lip not found in undamaged state; apparently thin as suggesting fragments. Moderate outward extension and development of concomitant subsutural concave belt on last whorl near last peristome of full grown shell. Short fold appearing on inner surface of flattened part of latest base near columella.

Ornament of few spiral lines on one early whorl. Growth lines prosocline, straight, and delicate on whorls, sickle shaped on base before last growth phase shell modifications then changing into widely parasigmoidal.

Remarks – The spirally ornamented early teleoconch(?) whorl and the extended last whorl support the proconulid family position of Csigabaga n. gen. in spite of the low early whorls, which might suggest belonging to Epulotrochidae .

Occurrence – Within Sinemurian to lowermost Pliensbachian (Lower Jurassic) part of the Hierlatz Limestone Formation in Hierlatz Alpe, Hallstatt, Austria.