Kittliconcha aonis ( Kittl, 1894 ) Hausmann & Nützel & Roden & Reich, 2021

Hausmann, Imelda M., Nützel, Alexander, Roden, Vanessa Julie & Reich, Mike, 2021, Palaeoecology of tropical marine invertebrate assemblages from the Late Triassic of Misurina, Dolomites, Italy, Acta Palaeontologica Polonica 66 (1), pp. 143-192 : 163-164

Family Settsassiidae Bandel, 1992 Genus Kittliconcha Bonarelli, 1927 Kittliconcha aonis ( Kittl, 1894) comb. nov.

Fig. 19A–C .

1894 Pseudomelania? aonis n. sp.; Kittl 1894: 194, pl. 6: 32–34, pl. 8: 19.

1978 Pseudomelania? aonis ; Zardini 1978: 46, pl. 41: 3.

Material.— Four specimens, all from surface samples; 2 from Lago Antorno ( PZO 12834 , 12835 , 2 figured specimens); 2 from Misurina Landslide ( PZO 12710 , 1 figured specimen; PZO 12709 , 1 specimen); Italy, Carnian , Triassic .

Description.—High-spired shell with very low, convex whorls that are ornamented with orthocline, broad irregular axial ribs; ribs are as wide as interspaces, irregular in strength, number and spacing; growth lines orthocline, distinct, irregular; axial ribs tending to be reduced on last preserved whorls; suture distinct; base convex with traces of spiral lirae and umbilical chink.

Remarks.—The present specimens closely resemble Kittl’s (1894) type specimens and those illustrated by Zardini (1978: pl. 41: 3). Kittl (1894) placed this species tentatively in the genus Pseudomelania . However, Pseudomelania is based on Cretaceous steinkerns and is therefore problematic. We place Pseudomelania? aonis in Kittliconcha , which has a similar gross morphology and axial ribbing (see Nützel 2010). The type species Kittliconcha obliquecostata has higher whorls and oblique axial ribs. The Palaeozoic genus Palaeostylus Mansuy, 1914 , is also similar. The species Kittliconcha aonis is insufficiently known i.e., its protoconch is unknown and its aperture is insufficiently known. Therefore, its systematic placement may change in the future.

Stratigraphic and geographic range.—Carnian, Upper Triassic; northern Italy (Cassian Formation).

Genus Tyrsoecus Kittl, 1892

Type species: Tyrsoecus cassiani Cox, 1960 ; Late Triassic , northern Italy .

Remarks.—The genus Tyrsoecus is problematic because it was based on Turritella compressa Münster, 1841 ( Tyrsoecus cassiani Cox, 1960 , is a replacement name) which was based on a poorly illustrated teleoconch fragment. According to Kittl (1894), the type specimen is lost.

Tyrsoecus zeuschneri (Klipstein, 1843) Fig. 19D, E .

1843 Turritella zeuschneri n. sp.; Klipstein 1843: 178, pl. 11: 24. 1849 Loxonema zeuschneri (Klipstein) ; Orbigny 1849: 187. 1894 Coronaria? zeuschneri (Klipstein) ; Kittl 1894: 167.? 1894 Coronaria subcompressa n. sp.; Kittl 1894: 166, pl. 4: 31, 32. 1909 Tyrsoecus zeuschneri (Klipstein) ; Cossmann 1909: 35. 1926 Stephanocosmia? zeuschneri (Klipstein) ; Diener 1926: 199. 1940 Stephanocosmia (Tyrsoecus) zeuschneri (Klipstein) ; Kutassy 1940:

369. non 1978 cfr. Coronaria zeuschneri (Klipstein) ; Zardini 1978: 41, pl.

26: 25.

Material.— One shell ( PZO 12837 ) from Lago Antorno surface sample, Italy, Carnian, Triassic. Klipstein’s (1843) illustrated type specimen ( NHMUK PI OR 35421 (1)) from unspecified locality, “St. Cassian” Formation .

Description.—Shell high-spired, present specimen from Lago Antorno is a teleoconch fragment of four whorls, 8.9 mm high, 4.6 mm wide specimen (flattened by compaction; 5.3 and 3.9 mm wide); the holotype from the Klipstein collection comprises c. six whorls, is 16.2 mm high, 7.0 mm wide; whorls low, stout, slightly adpressed; sutures distinct; whorls convex with slight median angulation which bears a faint spiral rib; additional faint spiral present; whorl with relatively weak axial ribs (12–14 per whorl) which do not reach sutures and are strongest at mid-whorl; whorl with faint, mostly obscured micro-striation; base flatly convex, without prominent ornament.

Remarks.— Tyrsoecus zeuschneri seems to be a rare species. Since its initial description, only a single specimen was assigned to this species as “cfr. Coronaria zeuschneri ” from Alpe di Specie ( Zardini 1978: 41–42, pl. 26: fig. 1; written as “cfr. Coronaria subcompressa ” in the plate caption). However, Bandel (1995) listed Zardini’s (1978) specimen in the synonymy list of the mathildoid species Camponaxis lateplicata (Klipstein, 1843) . Indeed, Zardini’s (1978) specimen is not very close to Klipstein’s (1843) illustration and type specimen. This illustration is inaccurate; it overemphasizes the axial ribs and does not show the slight median angulation. The type specimen housed in the Natural History Museum in London (NHMUK PI OR 35421(1)) agrees well with the specimen from the present collection. Tyrsoecus subcompressus ( Kittl, 1894) is close to T. zeuschneri and could represent a synonym.

Stratigraphic and geographic range.—Carnian, Upper Triassic; northern Italy (Cassian Formation).

Family Ladinulidae Bandel, 1992

Genus Flemingella Knight, 1936

Type species: Trochella prisca McCoy, 1844 ; Millicent , Clare, Ireland, Carboniferous .

Figures

Fig. 19. Caenogastropods from Lago Antorno (A, B, D), Misurina Landslide C) and Klipstein’s (1843) collection (E), northern Italy, Cassian Formation, Carnian, Upper Triassic. A. Kittliconcha aonis (Kittl, 1894), PZO 12834, in lateral view. B. Kittliconcha aonis (Kittl, 1894), PZO 12835, in lateral view. C. Kittliconcha aonis (Kittl, 1894); PZO 12710, in lateral view.D. Tyrsoecus zeuschneri (Klipstein, 1843); PZO 12837, in lateral view. E. Tyrsoecus zeuschneri (Klipstein, 1843), Klipstein’s (1843) illustrated type specimen NHMUK PI OR 35421(1)), in lateral (E1) and apertural (E2) views.