Persististrombus praecedens ( Schaffer, 1912 ) 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 : 789-795

Persististrombus praecedens ( Schaffer, 1912) comb. nov.

Fig. 4D .

1912 Strombus coronatus Defr. var. praecedens Schff. ; Schaffer 1912: 149, pl. 51: 21–22.

1971 Strombus (Canarium) bonelli praecedens Schaffer, 1912 ; Steininger et al. 1971: 391, pl. 9: 1.

1973 Strombus coronatus Defrance, 1827 ; Báldi 1973: 270, pl. 34: 7–8.

1975 Strombus coronatus Defrance, 1827 ; Báldi and Steininger 1975: 345, pl. 3: 6.

Lectotype: Schaffer (1912) illustrates two specimens without designat−

ing a type specimen; both specimens are stored in the GBA collection ( Schaffer 1912: fig. 21, GBA 1912/004/0011/1; fig.22, GBA 1912/004/ 0011/2). Herein, we designate the specimen illustrated as fig. 21 in Schaffer (1912) as lectotype.

Type locality: Loibersdorf, Austria.

Type horizon: North Alpine Foreland Basin, Loibersdorf Formation, Eggenburgian stage (= lower Burdigalian, Lower Miocene), ~20 Ma.

Material.— Four specimens in the NHMW collection and two specimens in the GBA collection from Loibersdorf , Austria .

Description.—A small Persististrombus , which does not exceed 75 mm in height. It is characterised by a high spire with an apical angle of 50–62 ° and a narrow last whorl with an angle of 31–36 °. The last whorl accounts for 75–80% of the total height. The spire is stepped; the whorls display a convexity in their middle, which grades into blunt nodes on the last spire whorl. The last whorl develops 6–7 long spiny nodes. These are oriented in adapical direction in Chattian specimens but more horizontal in early Burdigalian ones. The sur−

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face of the last whorl is nearly smooth except for faint traces of spiral threads. Additional spiral threads may occur on spire whorls and on the sutural ramp. A pronounced spiral swelling may appear in the lower third terminating in the stromboid notch. A shallow concavity arises below the spines on the outer surface of the wing. The wing is moderately wide, straight sided and terminates in a weakly thickened outer lip. The outline of the adapical part of the wing follows the slight sutural ramp of the last whorl. It is attached to the spines and does not reach up to the spire whorls.

Remarks.—This species seems to be a Paratethyan offshoot of P. nodosus from which it differs in its distinctly smaller size, the lower height of the spire whorls, and the fewer but much more prominent nodes. It might be closely related to the younger P. inflexus ( Eichwald, 1830) and is somewhat reminiscent of P. lapugyensis ( Sacco, 1893) . A specific separation is based on the smaller size, the lower number of spines, and the lower angle of the last whorl. Moreover, the spiral swelling in the last third of the last whorl is absent in P. inflexus . A separation from P. lapugyensis is further indicated by the strongly different angle of the aperture−plane relative to the axis, which ranges around 20 ° in P. praecedens but measures 25–30 ° in P. lapugyensis . Finally, the outer lip is strongly thickened in P. lapugyensis .

Stratigraphical and geographical range.—The species originates during the Late Oligocene (Chattian) when it is found as rare element in the Hungarian Basin ( Báldi 1973). By the Early Miocene (early Burdigalian) it is a typical species in the Loibersdorf Fauna of Lower Austria ( Steininger et al. 1971). There, it occurs in sandy coastal deposits associated with a shallow marine mollusc fauna dominated by turritellids, glycymerids and large cardiids (cf. Mandic et al. 2004). Reported occurrences of “ Strombus bonelli ”, also spelled as “ S. bonellii ”, in the middle and upper Burdigalian deposits of Bavaria and Austria ( Hölzl 1973; Harzhauser 2002) may also represent P. praecedens . The preservation of that material, however, does not allow a clear identification.

Persististrombus inflexus ( Eichwald, 1830) comb. nov. Fig. 5A–E .

1830 Strombus inflexus mihi; Eichwald 1830: 222.

1837 Strombus tuberculiferus M. de Serres ; Pusch 1837: 127, pl. 11: 12a, b.

1853 Strombus inflexus mihi; Eichwald 1853: 210, pl. 8: 18.

1853 Strombus coronatus Defr. ; Hörnes 1853: 187, pl. 17: 1.

1884 Strombus coronatus Defr. ; Hoernes and Auinger 1884: 163, pl. 18: 4–5, pl. 19: 1.

1893 var. voeslauensis ; Sacco 1893: 6 (referring to Hoernes and Auinger 1884, pl. 18: 4).

1893 var. propenodosa ; Sacco 1893: 6 (referring to Hörnes 1853, pl. 17: 1).

1893 var. enzesfeldensis ; Sacco 1893: 11 (referring to Hoernes and Auinger 1884, pl. 19: 1).

1912 Strombus Bonelli Brongn. ; Friedberg 1912: 136, text−fig. 38, pl. 7: 10.

1960 Strombus (Canarium) bonelli Brongniart, 1823 ; Kojumdgieva and Strachimirov 1960: 130, pl. 35: 3–4.

1966 Strombus bonellii Brongniart, 1823 ; Strausz 1966: 221, pl. 25: 1, pl. 66: 6.

1995 Strombus (Strombus) bonellii Brongniart, 1823 ; Bałuk 1995: 180, pl. 6: 4–10.

1998 Strombus (Strombus) coronatus Defrance ; Schultz 1998: 60, pl. 23: 6.

Material.— 36 specimens in the NHMW collection from the Vienna Basin (Grund, Niederleis, Enzesfeld, Vöslau, Baden, Steinebrunn, Grinzing) .

Description.—Moderately large robust shells of 70–90 mm height, with exceptionally large specimens of up to 108 mm. Mean apical angle ranges around 58 °; the bulky body whorl has an mean angle of 37 ° and accounts for 70–80% of the total height. A characteristic feature is that the knobby nodes on the spire whorls are often partly covered along their base by a concave sutural band of the following whorl. This feature causes a gradate or regularly conical spire outline. Spire whorls display fine spiral threads in the upper half; these are often crossed by growth lines resulting in a cancellate pattern. Strong spines are frequently developed along the shoul− der of the last whorl, usually pointing slightly in adapical direction. Their strength and number is highly variable and their morphology ranges from knobs to spiny nodes. The collection of the NHMW includes specimens with 4–9 spines, but also shells with strongly reduced spines.

While the last whorl of many species allocated to Persististrombus have an irregular shell surface with folds, knobs and/or axial swellings, the shell surface of the last whorl of Persististrombus inflexus is rather smooth. Nevertheless, several specimens display weak spiral ribs or faint spiral threads on the last whorl. A row of axially elongate nodes may occur close below the row of spines. If these knobs are reduced, at least an indistinct angulation is developed. The wing is wide and terminates in a convex margin with a considerably thickened outer lip. The tip of the wing is slightly expanding up to the height of the last spire whorl but its attachment does not reach above the shoulder or the suture. A thin glossy layer covers the base partly but never develops into a callous pad.

Remarks.—This species is larger and broader than Persististrombus exbonellii ( Sacco, 1893) . The sutural ramp is wider than in P. lapugyensis ( Sacco, 1893) but distinctly shorter than in P. exbonellii . The reduced surface sculpture, the lack of a spiral swelling in the lower third of the last whorl, the wider wing with the expanding tip, and the convex margin of the thickened outer lip allow a separation from the older P. nodosus . In addition, the spire whorls of P. nodosus are often undercut by the sutures but gradate in P. inflexus .

This species was originally described from the Polish−Carpathian Foredeep ( Eichwald 1830). The description of Eichwald (1830) appears in a footnote in Latin. Therefore, the name Strombus inflexus is available from Eichwald (1830) and is clearly valid. The illustration of the specimen appeared much later, in Eichwald (1853). Thereafter, this taxon was ignored as most palaeontologists considered the Paratethyan specimens as conspecific with Strombus coronatus Defrance, 1827 or S. bonelli Brongniart, 1823 (= P. nodosus ( Borson, 1820)) , which then would have gained priority. Sacco (1893) doubted this synonymy and created a set of new variation names based on Hörnes (1853) and Hoernes and Auinger (1884) without considering S. inflexus Eichwald, 1830 and without studying the concerned specimens personally.

The type specimen in Eichwald (1853) is a robust specimen with reduced sculpture, knobby spines and poorly defined nodes on the spire whorls. This morphology is prevalent in the Northern Carpathian Foredeep (e.g., Bałuk 1995) and also typical in the Pannonian Basin ( Strausz 1966) and in Bulgaria ( Kojumdgieva and Strachimirov 1960). Although this morphotype is predominant, Hörnes (1853: pl. 17: 1) and Hoernes and Auinger (1884: pl. 18: 4) illustrated a rare spiny morphotype with pronounced sculpture. Sacco (1893) proposed the variety names Strombus nodosus var. propenodosa and Strombus nodosus var. voeslauensis , respectively, for these shells although both derive from the same clay pit at Vöslau close to Vienna. Thus, this certain morphotype seems to be mainly found in pelitic deposits and might have preferred slightly deeper soft bottom habitats.

Persististrombus inflexus was probably not restricted to the Paratethys. Shells from the Middle Miocene of the Touraine in France, mentioned and illustrated by Gignoux (1913), Peyrot (1938), Glibert (1949; 1952), and those from the Turkish Karaman Basin ( Erünal−Erentöz 1958; and in the collections

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of the Naturalis Biodiversity Center) are considered herein to belong to the same lineage.

Stratigraphical and geographical range.—Widespread during the Langhian and Early Serravallian in the entire Central Paratethys. Langhian occurrences from the proto−Mediterranean are unknown probably because of the low amount of shallow marine fossiliferous Middle Miocene deposits in that area. The species (or a closely related species) reached the Loire Basin along the Atlantic coast and the Karaman Basin in Turkey during the Serravallian.

Persististrombus exbonellii ( Sacco, 1893) comb. nov. Figs. 6A–E , 7A .

1853 Strombus bonellii Brong. ; Hörnes 1853: 189, pl. 17: 2–6.

1884 Strombus bonellii Brongn. ; Hoernes and Auinger 1884: 164, pl. 19: 2a, 2b.

1893 var. exbonellii ; Sacco 1893: 11 (referring to Hoernes and Auinger 1884, pl. 19: fig. 2).

Holotype: NHMW1855/0045/0419, complete shell ( Fig. 6B ).

Type locality: Gainfarn, Austria.

Type horizon: Vienna Basin, Badenian (= Langhian, Middle Miocene), upper Lagenidae Zone ; ~14.5–14.0 Ma; illustrated in Hoernes and Auinger (1884: pl. 19: 2a, 2b).

Material.— 70 specimens from the NHMW collection from Gainfarn and Vöslau (Vienna Basin, Austria) .

Description.—Elongate and rather delicate shells of 60–90 cm adult height. Protoconch with 3.25–3.75 smooth rapidly enlarging whorls of increasing convexity. Nepionic whorl slightly sunken. Close to the abapical suture one specimen exhibits faint traces of a spiral ornamentation on the last protoconch whorl. Spiral ribs of the teleoconch start abruptly after the slightly opisthocyrt termination of the protoconch. The high spire has an apical angle of 51–65 ° with a mean of 57 °. The body whorl angle of adult specimens ranges from 30 ° to 40 ° with a mean of 35 °; its height accounts for 76% of the total height on average. The spire whorls are high and develop indistinct knobs or only a weak angulation. The last whorl develops a shoulder with nodes or spines, which is separated from the thread−like sutures by a wide and steep sutural ramp. The specimens are characterised by reduced sculpture; spines are restricted to the dorsal part of the last whorl and are only developed on adult specimens. Their number ranges around 4–5; higher numbers are very rare whilst many species lack spines even as adults. No additional spiral ribs with nodes are usually developed on the last whorl, although a distinct angulation may occur. The ventral part of the last whorl is smooth, covered by a thin slightly glossy layer. Its shoulder is only slightly angulated and lacks any nodes or spines. Shell surface is usually smooth; spiral sculpture is strongly reduced but may be present in the upper part of the spire whorls and sometimes may appear close to the edge of the outer lip. The wing is thin shelled and terminates in an insignificantly thickened lip, with slightly convex margin in most specimens. Typically, the wing expands slightly adapically and is attached to the shoulder or may even reach up to the suture. Its posterior part of the wing is always sloping without forming a tip or lobe.

Remarks.—The high, regularly conical spire and the sloping sutural ramp with the low position of the shoulder on the last whorl are unique in Persististrombus . The angle formed by the aperture−plane relative to the shell axis ranges from 16 ° to subparallel, whilst all other species display a larger angle.

We consider this taxon to be an offshoot from the widespread Persististrombus inflexus −lineage. However, it should be noted that P. exbonellii has only a limited, i.e., local, distribution. It is also restricted to a very short time slice within the Middle Miocene, and may therefore be an ecomorph. On the other hand, in its high abundance (it is represented by hundreds of shells in many museum and private collections) it is very homogenous in its morphology. The commonness of this species was the main reason for the long discussions by Hörnes (1853) and Hoernes and Auinger (1884) about the presence of Strombus bonelli within the Middle Miocene of the Vienna Basin.

Stratigraphical and geographical range.—This species is known so far only from the area of Gainfarn and Vöslau in Lower Austria. There, it developed a huge populations in seagrass meadows within a protected embayment ( Zuschin et al. 2007).

Persististrombus lapugyensis ( Sacco, 1893) comb. nov. Fig. 8A–C .

1884 Strombus coronatus Defr. ; Hoernes and Auinger 1884: 163, pl. 18: 1–3.

1884 Strombus bonelli Brongn. ; Hoernes and Auinger 1884: 164, pl. 19: 3–4.

1893 S. coronatus la var. lapugyensis ; Sacco 1893: 11 (referring to Hoernes and Auinger 1884, pl. 18: 1).

Holotype: NHMW1866/0040/0270, adult specimen ( Fig. 8C ).

Type locality: Lãpugiu de Sus (= Lapugy), Romania.

Type horizon: Transylvanian Basin, Badenian (= Langhian, Middle

Miocene), lower Lagenidae Zone ; ~16–15 Ma; illustrated in Hoernes and Auinger (1884: pl. 18: 1).

Material.— 29 specimens in the NHMW collection from the Transylvanian Basin (localities Lãpugiu de Sus , Bujtur, Coşteiu de Sus), Romania .

Description.—Robust shells; moderately high spire with a mean apical angle of 62 °. The height of adult shells ranges from 50 to 110 mm with a mean of 87 mm; the body whorl height attains up to 90% of the total height with a mean of 79%. The last spire whorl, and sometimes already the penultimate one, develop pronounced spines; the suture of the following whorl runs distinctly below these spines. The last whorl is characterised by 7–9 very large and long spines; most shells bear 8 spines; rarely up to 12 may be developed. The low sutural shelf is smooth or may bear faint spiral threads. Below the shoulder, the smooth last whorl is rapidly

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contracting with a mean angle of 35 °. Rarely, a spiral row of low nodes is developed which terminates in the wide stromboid notch. The wing is expanding and grades into a strongly thickened outer lip. A glossy sheet of several layers covers the base but never forms a callous pad.

Remarks.—These shells were the main reason for the frequent confusion by many authors with the Pliocene Persististrombus coronatus ( Defrance, 1827) . Sacco (1893) recognized that the specimens from the Paratethys are not fully conspecific with the younger Italian ones representing true P. coronatus ( Fig. 4E ). He tried to overcome this problem by proposing the variation name Strombus coronatus lapugyensis for the stratigraphically older specimens. The similarities with P. coronatus , however, are only superficial. A main difference is the morphology of the spire: the fourth and fifth teleoconch whorls of P. coronatus are very low. Therefore, the suture runs along the backs and tips of the spines of the preceding whorls. In contrast, the sutures of the corresponding whorls of P. lapugyensis are usually distinctly below the knobs. Juvenile shells of P. coronatus develop a distinct shoulder of the last whorl, whereas juveniles of P. lapugyensis display a convex outline without prominent shoulder. The stromboid notch of P. lapugyensis (and all other species) is shallower and relatively wider than that of P. coronatus . The Pliocene strombid tends to develop two spiral ridges or two rows of knobs on the dorsal side of the last whorl aside from the shoulder spines. P. lapugyensis lacks the middle row and even the lower row occurs only in few specimens.

We consider this taxon to be a geographically distinct offshoot of Persististrombus inflexus . It seems to be restricted to the early Langhian in the Transylvanian Basin, where it occurs in large numbers. Its occurrence coincides with the Middle Miocene Climatic Optimum (Harzhauser and Piller 2007) and thus, this species might be indicative of near−tropical conditions in the southern Paratethys Sea during the early Langhian. This is supported by the co−occurrence of the strombid Europrotomus schroeckingeri (Hörnes in Hoernes and Auinger 1884), which is restricted to this short time span and was shown to be a thermophilic species by Kronenberg and Harzhauser (2012).

Stratigraphical and geographical range.— Persististrombus lapugyensis is restricted to the early Badenian (early Langhian) of the Transylvanian Basin where it is recorded from Lãpugiu de Sus, Bujtur and Coşteiu de Sus in Romania.

Figures

Fig. 4. Miocene–Pliocene strombid gastropods from Europe. A–C. Persististrombus nodosus (Borson, 1820) from the Burdigalian (Early Miocene). A. NHMW1911/0006/0290, Pelona, France. B. NHMW 2013/0299/001, Saucats, France. C. NHMW1851/0017/0116; Colli Torinesi, Italy. D. Persististrombus praecedens (Schaffer, 1912) from the Burdigalian of Loibersdorf in Lower Austria, NHMW1866/0011/0004. E. Persististrombus coronatus (Defrance, 1827) from the Pliocene of Tresanti in Italy, NHMW A2588. Dorsal (A1–E1), ventral (A2–E2), lateral (A3–E3), and apical (A4–E4) views. Scale bars 10 mm.

Fig. 5. Strombid gastropod Persististrombus inflexus (Eichwald, 1830) from the Middle Miocene of the Vienna Basin. A. NHMW2012/0080/0001, Vöslau. B. NHMW2012/0081/0001, Enzesfeld. C. NHMW1855/0002/0052, Enzesfeld, illustrated in Hoernes and Auinger (1884: pl. 19: 1). D. NHMW1874/ 00024/0041, Vöslau, illustrated in Hoernes and Auinger (1884: pl. 18: 4). E. NHMW 2012/0081/0002, Enzesfeld. In dorsal (A1–E1), ventral (A2–E2), lateral (A3–E3), and apical (A4–E4) views. Scale bars 10 mm.

Fig. 6. Strombid gastropod Persististrombus exbonellii (Sacco, 1893). A–D. Middle Miocene of Gainfarn in Lower Austria. A. NHMW1855/0045/0420. B. NHMW1855/0045/0419. C. NHMW1846/0037/0185. D. NHMW1847/0037/0058. E. NHMW62275, Middle Miocene of Vöslau in Lower Austria. 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.

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.