Foveolaria suemegensis, Szabó, 2016

Szabó, János, 2016, Gastropods of the Lower Jurassic Hierlatz Limestone Formation, part 2. Some new archaic type slit-bearing components from the fauna of the Hierlatz Alpe (Hallstatt, Austria) and the Bakony Mts (Hungary), Fragmenta Palaeontologica Hungarica 33, pp. 3-30 : 24-25

Foveolaria suemegensis n. sp.

( Figs 32–36 )

1980 Sisenna cf. procera (Deslongchamps, 1849) – SZABÓ, p. 55, Pl. I, Figs 2–3 .

2009 Wortheniopsis (Sisenna) aff. lokutensis Szabó, 2009 – SZABÓ, p. 34, Fig. 27 A-B.

Type specimen – GGIH J.08.8.1.

Type locality – Mogyorósdomb , Sümeg, Bakony Mts ( Hungary).

Type strata – Upper ? Sinemurian (Lower Jurassic) Hierlatz Limestone .

Derivation of name – From the name of town Sümeg.

Diagnosis – Shell having rather high spire and slightly acute early teleoconch. Marked angulation of whorl surface providing slightly pagodiform outline. Ramp feebly convex initially then feebly concave on last whorl. Outer face concave, its basal rim similarly angular to whorl surface. Initially abaxial rim of base then angulation at abapical rim of selenizone corresponding to periphery. Base with moderately convex wall. Weak spiral lines ornament whorls, crossed by thin, collabral threads on early whorls with granules at intersections. Two stronger threads in middle of ramp present on all visible whorls, except last one.

Material – Single, fragmentary specimen without earliest whorls and peristome.

Dimensions – Preserved width: 33 mm; earliest measurable spiral angle: 55°; spiral angle on last whorl: 63°.

Description – A clearly gradate shell which has a relatively high spire with slightly acute early teleoconch. No information is available from the protoconch. A marked angulation is present on the whorl surface already from the early shell that causes a slightly pagodiform outline. The ramp is feebly convex on the early whorls but becomes feebly concave for the last whorl. The outer face is concave, its basal rim similarly angular to that on the whorl surface. Initially, the abaxial rim of the base then the angulation at the abapical rim of selenizone corresponds to the periphery. The base seems fairly convex from the available fragment as whole and has a moderately convex wall.

Weak spiral lines ornament the whorls, crossed by thin collabral threads on the early whorls with granules at the intersections. Two marked threads in the middle of the ramp are present on all visible whorls, except the last one. The outer face is ornamented by several equally spaced, obscure spiral striae.

Remarks – The slightly acute spire and the marked, keel-like angulation of the whorls suggested affinity of the species to Pleurotomaria faveolata var. procera J. A. Eudes-Deslongchamps, 1849 drawings ( SZABÓ 1980) but photos in FISCHER & WEBER (1997) display a specimen as “morphe ” procera that is strongly different from the earliest figures and not similar to the Sümeg specimen. The shell is somewhat similar to that of Foveolaria lokutensis ( Szabó, 2009) therefore the name Wortheniopsis (Sisenna) aff. lokutensis has been given to this species subsequently. Since the earliest parts are slightly acute and the angulations of the whorls are more distinct, keel like, while the shell outline is simply conoidal in F. lokutensis , the ramp is narrower and the outer face is wider than in F. lokutensis , establishing a new species seems satisfactorily supported by the morphology.

Distribution – Upper(?) Sinemurian Hierlatz Limestone, Mogyorósdomb, Sümeg, Bakony Mts, Hungary.

Figures

Figs 30–36. New species of Foveolaria n. gen.from the Bakony Mts, Hungary localities of the Hierlatz Limestone Formation. – 30–31. Holotype of Foveolaria kocsisi n. sp., GGIH J.08.9.1. from beds with Obtusum to Ibex Zones (Upper Sinemurian to Lower Pliensbachian, Lower Jurassic) mixed fauna in Hierlatz Limestone at Kericser-dűlő, Lókút, Bakony Mts, Hungary. – 30. The only preserved whorl and base parts, ×1. – 31. The same in ×3.5 magnification for the details. – 32–36. Holotype of Foveolaria suemegensis n. sp., GGIH J.08.8.1. from the (?)Upper Sinemurian (Lower Jurassic) Hierlatz Limestone of Mogyorósdomb, Sümeg, Bakony Mts, Hungary. – 32–33. Most informative surface parts of the monotype, ×1. – 32. Nearly parallel view to the inferable peristome plane, showing a short part of the outer lip below the suture. – 33. The shell from the opposite side. – 34. Weakening ornament of the early spire whorls, ×2.5. – 35. Magnified sample view of the obscure ornament on the ramp of the latest whorls, ×5.– 36. Networkornament of the early spire,×4.5

Figs 1–3. The peculiar “quirinii type” ridges, occurring in Wortheniopsis Böhm, 1895, Foveolaria n. gen. and some probably related forms. – 1. Copy of KITTL’s (1899, p. 14, Fig. 2) sketch. – 2. The ridges on the outer face and on the base of Wortheniopsis rakusi n. sp. – 3. The ridges on the base of Foveolaria conoidea n. sp.

Figs 15–29. New species of Foveolaria n. gen. from the Sinemurian to lowermost Pliensbachian interval (Lower Jurassic) of the Hierlatz Limestone in the Hierlatz Alpe, Hallstatt, Austria. – 15–18. Holotype of Foveolaria bicarinata n. sp., GBA 2017/001/0003, all ×3.8. – 15. Dorsal view. – 16. Apical view. – 17. Basal view. – 18. Peristomal view. – 19–22. Holotype of Foveolaria conoidea n. sp., GBA 2017/001/0004, all ×4. – 19. Dorsal view. – 20. Apical view. – 21. Basal view. – 22. Peristomal view.– 23–26. Holotype of Foveolaria globosa n. sp., GBA 2017/001/0005, all ×4. – 23. Dorsal view. – 24. Apical view. – 25. Basal view. – 26. Peristomal view. – 27–29. Foveolaria sp., GBA 2017/001/0006, all ×4. – 27. Apertural view. – 28. Basal view. – 29. Dorsal view