Persististrombus pannonicus, Harzhauser & Kronenberg, 2013

Harzhauser, Mathias & Kronenberg, Gijs C., 2013, The Neogene strombid gastropod Persististrombus in the Paratethys Sea, Acta Palaeontologica Polonica 58 (4), pp. 785-802 : 795

Persististrombus pannonicus sp. nov.

Fig. 8D, E .

1932 Strombus coronatus Defr. ; Janoschek 1932: 75, 83, 85.

1932 Strombus (Canarium) bonelli Brongn. ; Janoschek 1932: 75.

Etymology: Referring to the Roman province of Pannonia.

Type material: Holotype: NHMW 1930 /0006/0058, height: 88.8 mm, diameter: 78.4 mm, Ritzing, Fig. 8D ; Paratype: NHMW 1970 /1396/ 0609, height: 102.7 mm, diameter: 86.9 mm, Brennberg, Fig. 8E .

Type locality: Ritzing , Kuchelbach section, Oberpullendorf Basin, Austria .

Type horizon: Coastal sand of the Ritzing Formation, Badenian, Serravallian, Middle Miocene; c. 13 Ma.

Material.—Six shells from Ritzing and Brennberg ( Austria) in the NHMW collection.

Description.—Bulky robust shells with pronounced sculpture. The height ranges around 80–100 mm; the spire is broad with an angle of c. 60–70 °. Nodes appear already on the penultimate spire whorl and grade into prominent spines on the last spire whorl. Early spire whorls are covered up to their middle by the following whorl, often forming a wavy sutural band, which covers the spines up to just below their tips. On later spire whorls, the suture is gradually shifting slightly below the tips of the spines but the following whorl covers always the base of the spines. The spines of the last whorl are very irregular in shape; they are axially elongate at their base, much higher than wide in cross section, and often display concave areas along their flanks. They are deflected leftwards in apical view and point in adapical orientation. Aperture moderately wide with broad sinuous adapical tip which is attached to the suture; outer lip thickened with straight sided or sigmoidal margin. Shell surface of adult shells smooth; only subadults display weak spiral threads.

Remarks.—The sculpture of this species is highly reminiscent that of P. coronatus . The two forms differ, however, in the wider and shallower stromboid notch and the higher spire of P. pannonicus . The angle of the last whorl is smaller compared to the squat P. coronatus and the surface of the last whorl lacks the spiral sculpture of nodes as typical for P. coronatus . Its adult shells do not attain the large size of P. coronatus . Despite the similarities, we consider this taxon to be a distinct species, which derived from the P. inflexus −lineage, occupying the morphospace that is realized later by P. coronatus during the Pliocene. Coeval shells from the more northern Vienna Basin (e.g., Grinzing section) represent typical P. inflexus .

The laterally compressed morphology of the spines is unique within Paratethyan representatives of Persististrombus inflexus and allows a clear separation from the older P. lapugyensis . Moreover, the spines of the last spire whorl are free in P. lapugyensis but partly covered in P. pannonicus .

The type of spine morphology might be characteristic for late Middle Miocene shells of a species related to the Persististrombus inflexus −lineage. Shells in the collection of the Naturalis Biodiversity Center from the Serravallian of the Turkish Karaman Basin ( Fig. 7B ) display similar tendencies. Their spire angle is smaller than in P. pannonicus , the shells are more elongate on average, and the largest shells attain up to 107 mm in height.

Stratigraphical and geographical range.—This species is known so far only from the late Badenian of the Oberpullendorf Basin within the Pannonian basins complex, where it was found at several localities ( Janoschek 1932).

Figures

Fig. 8. Strombid gastropods from Europe. A–C. Persististrombus lapugyensis (Sacco, 1893) from the Langhian (Middle Miocene) of Lãpugiu de Sus in Romania. A. NHMW1854/0035/0150. B. NHMW1855/0043/0017. C. NHMW1866/0040/0270, illustrated in Hoernes and Auinger (1884: pl. 18: 1). D, E. Persististrombus pannonicus sp. nov. from the Serravallian of the Oberpullendorf Basin. D. Holotype, NHMW1930/0006/0058, Ritzing, Austria. E. Paratype, NHMW1970/1396/0609, Brennberg, Austria. Note the different angles between the aperture and the axis in both species (A3–E3) and the different spine morphology (A4–E4). In dorsal (A1–E1), ventral (A2–E2), lateral (A3–E3), and apical (A4–E4) views. Scale bars 10 mm.

Fig. 7. Strombid gastropods from Austria and Turkey. A. Juvenile specimen with protoconch of Persististrombus exbonellii (Sacco, 1893), NHMW 2013/0299/0002, from the Middle Miocene of Gainfarn in Lower Austria, in ventral (A1, A2), and apical (A3) views. B. Protoconch of Persististrombus inflexus, NHMW 2013/0299/0003, from the Serravallian of Karaman in Turkey, in ventro−apical (B1) and ventral (B2) views. Scale bars 1 mm.