107,510 research outputs found
Cyclotopsis praecursor Neubert & Damme 2012, sp. nov.
No full textCyclotopsis praecursor sp. nov. (Figs. 8–9) Type specimens: Holotype NMBE 5018970; paratypes NMBE 5018971–5018973, MNHN/25, SMF 340184/25; paratypes Wadi Darbat, NMBE 5018974, 5019038– 5019043. Type locality: Thaytiniti, Dhofar, Oman. Stratum typicum: Paludal biomicritic limestones of the Zalumah Formation. Age: Late Priabonian. Material: This species is very abundant at Thaytiniti and Wadi Darbat. Etymology: praecursor from Latin for predecessor, a noun in apposition. Diagnosis: A fossil species of Cyclotopsis with a slightly elevated spire and an operculum with a lamella-like coiled spiral. Description: Shell much broader than high, spire slightly elevated; protoconch relatively large, consists of 2 whorls, surface sculpture not preserved; teleoconch of 3.5–4 rapidly increasing whorls; surface sculpture of 3–5 strong spirals (only preserved on the upper whorls); last whorl only slightly descending before the aperture; aperture almost circular, with a slightly thickened lip; umbilicus very large, broad dish-like, umbilical walls very probably smooth; operculum multispiral, spiral consisting of a broad raised lamella of at least 3 whorls. Measurements: Holotype (Fig. 8): H = 6.73 mm; W = 9.18 mm; h = 4.42 mm; w = 4.25 mm; Wh = 5.5. Remarks: Roger & al. (1994) probably refer to eroded specimens of this species as 'cf. valvata '. The preservation state of the specimens from the type locality in Thaytiniti is quite poor and mainly consists of internal casts. However, in a few cases, remains of the shells themselves are preserved, allowing reconstructing of some details of the surface sculpture. These specimens display the same teleoconch sculpture as the specimens from Wadi Darbat (Fig. 9), where the preservation state is much better (but no specimen with an operculum could be traced there). This fossil species is placed in the extant genus Cyclotopsis, because it is almost indistinguishable from the few species from India (for comparison see the syntype of Cyclostoma semistriatum SOWERBY, 1843 (Fig. 10), the type species of Cyclotopsis). It shares autapomorphic details of umbilicus and operculum together with the spiral sculpture of the teleoconch. It differs from most of the Soqotran species of Dioscopoma NEUBERT, 2009, which usually have a reticulate surface sculpture, a more narrow umbilicus, and an operculum with a flat sutural line and not a raised spiral; also, most of the species of Dioscopoma display a spiral sculpure on the inner umbilical wall, which is very probably smooth in C. praecursor sp. nov. Today, the Dhofar area is inhabited by two species of the genus Rochebrunia BOURGUIGNAT, 1881, but these have larger shells with a closed umbilicus and an almost smooth operculum. For a more detailed discussion of the pomatiid genera and species of the area see Neubert (2009), and for pomatiid operculum structure Wilmsmeier & Neubert (2012).Published as part of Neubert, Eike & Damme, Dirk van, 2012, Palaeogene continental molluscs of Oman, pp. 1-28 in Contributions to Natural History 20 on pages 10-12, DOI: 10.5169/seals-787080, http://zenodo.org/record/583854
Succinea omanensis Neubert & Damme 2012, sp. nov.
No full textSuccinea omanensis sp. nov. (Figs. 11–12) Type specimens: Holotype NMBE 5018975; paratypes NMBE 5018976, 5019044; paratypes Thaytiniti NMBE 5019045–5019047. Type locality: Wadi Darbat, Dhofar, Oman. Stratum typicum: Paludal biomicritic limestones of the Zalumah Formation. Age: Late Priabonian. Material: Only known from the type locality. Diagnosis: A small shelled member of Succinea, with a rapidly growing teleoconch and the last whorl exceeding half of the complete height of the shell. Etymology: omanensis refers to the provenance of this new species. Description: Small shells with a rapidly growing teleoconch, shells probably reach a total shell length of about 10 mm; preserved paratype shell with almost 4 whorls, protoconch eroded; suture shallow, well-marked and somewhat reinforced, subsuturally slightly crenulate; teleoconch covered by a regular pattern of fine, axial growth riblets; last whorl amply open, constituting more than half of the complete height of the shell. Measurements: Holotype (Fig. 11): H = 4.94 mm; Wh 3.5. Remarks: It has to be stressed that the affiliation of this species to the extant genus Succinea is debatable. However, the shells are in fact quite similar to a number of Modern species within Succinea and related genera, which today are defined by using anatomical and molecular data, inapplicable to fossils. Creating a fossil genus to harbour these shells seems not to be advisable as long as material is so meagre and good arguments in favour of such a genus are available. Today, there are only two records of an extant succineid species from the Arabian Peninsula, i.e. Quickia concisa (MORELET, 1848). The shell of this species is smaller, and it has a deep and simple suture, and thus cannot be identified with the fossil specimens from Wadi Darbat (Neubert 1998: 370, fig. 63).Published as part of Neubert, Eike & Damme, Dirk van, 2012, Palaeogene continental molluscs of Oman, pp. 1-28 in Contributions to Natural History 20 on pages 12-13, DOI: 10.5169/seals-787080, http://zenodo.org/record/583854
Cerastus praeinsularis Neubert & Damme 2012, sp. nov.
No full textCerastus praeinsularis sp. nov. (Figs. 18–19) Type specimens: Holotype NMBE 5018986, paratype NMBE 5019050. Type locality: Wadi Darbat, Dhofar, Oman. Stratum typicum: Paludal biomicritic limestones of the Zalumah Formation. Age: Late Priabonian. Material: This species is only represented by the holotype specimen. Etymology: praeinsularis to pinpoint the early presence of this species in the area, which later gave rise to the Soqotra Archipelago, Yemen. Diagnosis: Species characterised by the large periomphalum. Description: Shell elongate turreted, with regularly increasing whorls (protoconch and first teleoconch whorl not preserved); upper teleoconch whorls covered by a fine axial sculpture of ribs; aperture broadly oval, columellar part triangular, partly covering the umbilicus; umbilicus broadly open, with a large periomphalum, delimited by a blunt crest (see arrows in Fig. 18b). Measurements: Holotype (Fig. 18a): H = 11.81 mm; Wh > 5. Remarks: For the familial and generic affiliation, the same rationale is used as in C. pseudoena sp. nov. However, the peculiar form of the umbilicus of C. praeinsularis sp. nov. clearly differs from that of its fossil congener, but is quite similar to species from the Soqotran cerastid radiation. In this respect, it particularly resembles shells of the Modern endemic Soqotran genera Achatinelloides NEVILL, 1878, and Passamaella PFEIFFER, 1877 (Neubert 2005a, 2005b). This is here shown by a comparison with Achatinelloides hadibuensis (GODWIN-AUSTEN, 1881) (Fig. 20), which shows a very similar umbilicus formation with a large periomphalum delimited by a blunt crest (see arrow in Fig. 20). In our material, we also found a small shell consisting of a small protoconch and almost four teleoconch whorls, which are also covered by a dense pattern of axial ribs (Fig. 19). The imperfect formation of the aperture makes it very probable that this is a juvenile shell. Superimposing this fossil with the holotype of C. praeinsularis sp. nov. reveals that the diameter and growing increment of both shells match almost perfectly. For this reason we interpret this shell as a juvenile of C. praeinsularis sp. nov. (NMBE 5019050).Published as part of Neubert, Eike & Damme, Dirk van, 2012, Palaeogene continental molluscs of Oman, pp. 1-28 in Contributions to Natural History 20 on pages 18-19, DOI: 10.5169/seals-787080, http://zenodo.org/record/583854
Lanistes thaytinitiensis Neubert & Damme 2012, sp. nov.
No full text<i>Lanistes thaytinitiensis</i> sp. nov. (Fig. 7) <p>Type specimens: Holotype NMBE 5018966; paratypes NMBE 5018967–5018969, MNHN/2, SMF 340185 /2.</p> <p>Type locality: Thaytiniti, Dhofar, Oman.</p> <p>Stratum typicum: Paludal biomicritic limestones of the Zalumah Formation.</p> <p>Age: Late Priabonian.</p> <p>Material: This species was only recovered from the Zalumah exposures at Thaytiniti. Collected by M. Pickford during one of the palaeontological missions led by H. Thomas in 1988–1990.</p> <p>Etymology: named after the type locality.</p> <p> Diagnosis: A palaeogene species of <i>Lanistes</i> characterized by the discoid shape and flattened upper side.</p> <p> Description: Medium sized <i>Lanistes</i>; discoid shell consisting of 4 <i>½</i> whorls with virtually no exserted spire, apex pointed; upper part of the gradually increasing whorls completely flattened, lower part convex, forming a peripheral angle accentuated by a ridge; at the base the periphery of the whorls form a second angle with the flattened walls of the umbilicus, in which the whorls wind downwards (or upwards being hyperstrophic) in a regular spiral; aperture horizontal at the top, the outer margin convex, the upper part of the inner margin, connected to the shell, concave and the free lower part straight, basal margin pointed; growth lines regular and fine, no spiral sculpture; operculum unknown.</p> <p>Measurements: Holotype (Fig. 7): H = 12.5 mm; W = 38.2 mm; h = 12.0 mm; w = 11.5 mm. Paratype (NMBE 5018967): H = 11.2 mm; W = 32.2 mm; h = 11.2 mm; w = 10.3 mm.</p> <p> Remarks: We did not find any fossils of this species in the Salalah region, while in the Zalumah exposures at Thaytiniti is seems to be the most common of the two <i>Lanistes</i>. This indicates either a difference in age or in environmental conditions between these two sites. <i>Lanistes thaytinitiensis</i> sp. nov. is the only flattened discoid <i>Lanistes</i> species known.</p>Published as part of <i>Neubert, Eike & Damme, Dirk van, 2012, Palaeogene continental molluscs of Oman, pp. 1-28 in Contributions to Natural History 20</i> on pages 9-10, DOI: 10.5169/seals-787080, <a href="http://zenodo.org/record/5838544">http://zenodo.org/record/5838544</a>
Comatricha elegans var. microspora H. Marx, in Neubert, Nowotny & Baumann
No full text* Comatricha elegans var. microspora H. Marx, in Neubert, Nowotny & Baumann (1 FC, 1 loc, 1 ps) Loc. 24 Praslin: On wood of rotten log of Calophyllum inophyllum, AM2786, TK2205.Published as part of Kryvomaz, Tetiana, Michaud, Alain & Stephenson, Steven L., 2020, Myxomycete biodiversity on five islands of the Seychelles, pp. 201-244 in Zootaxa 4851 (2) on page 224, DOI: 10.11646/zootaxa.4851.2.1, http://zenodo.org/record/440741
Arcyria helvetica H. Neubert, Nowotny & K. Baumann 1989
No full text* Arcyria helvetica (Meyl.) H. Neubert, Nowotny & K. Baumann (1 MC, 1 loc, 1 ps) Loc. 17b Praslin: On bark of large stump of Calophyllum inophyllum, SLS 324995 (MC pH 6.1).Published as part of Kryvomaz, Tetiana, Michaud, Alain & Stephenson, Steven L., 2020, Myxomycete biodiversity on five islands of the Seychelles, pp. 201-244 in Zootaxa 4851 (2) on page 222, DOI: 10.11646/zootaxa.4851.2.1, http://zenodo.org/record/440741
Trochozonites arabica Neubert & Damme 2012, sp. nov.
No full textTrochozonites arabica sp. nov. (Fig. 25) Type specimens: Holotype NMBE 5018988. Type locality: Wadi Darbat, Dhofar, Oman. Stratum typicum: Paludal biomicritic limestones of the Zalumah Formation. Age: Late Priabonian. Material: This species is only represented by the holotype specimen. Etymology: arabica for its presence on the Arabian Peninsula. Diagnosis: Broad conical shell with strong opisthocline ribs. Description: Shell broad conical; protoconch blunt, consisting of ca. 2 whorls without any obvious sculpture; last teleoconch whorl rapidly increasing, with a sharp peripheral keel; whorls only slightly rounded, suture simple and shallow; teleoconch whorls covered by strong opisthocline ribs; lower part of the shell (below the periphery) smooth; aperture depressed oval, peristome (probably) simple, sharp; form of umbilicus not clearly discernible, however, it seems to be quite narrow. Measurements: Holotype (Fig. 25): H = 5.04 mm; W = 5.27 mm; Wh > 5. Remarks: The specific opisthocline ribs discriminate this shell from all cerastid shells, which have orthocline ribs. The shell form immediately recalls the shells of the afrotropical helicarionid genus Trochozonites PFEFFER, 1883. To facilitate comparison, the figure of Trochozonites plumaticostata PILSBRY, 1919 from the Congo Basin is here provided (Fig. 26). In his diagnosis of the species, Pilsbry (1919: 251) explicitly describes the "oblique, rather widely spaced, retractive, undulating riblets", which is close to what can be seen in T. arabica sp. nov. Nonetheless, the affiliation to such a badly understood genus remains with some doubts, because important character sets like the protoconch sculpture and microrelief are not preserved.Published as part of Neubert, Eike & Damme, Dirk van, 2012, Palaeogene continental molluscs of Oman, pp. 1-28 in Contributions to Natural History 20 on pages 20-22, DOI: 10.5169/seals-787080, http://zenodo.org/record/583854
Achatina sculpturata Neubert & Damme 2012, sp. nov.
No full textAchatina sculpturata sp. nov. (Fig. 15) Type specimens: Holotype NMBE 5018982; paratypes NMBE 5018983 – 5018984. Type locality: Wadi Darbat, Dhofar, Oman. Stratum typicum: Paludal biomicritic limestones of the Zalumah Formation. Age: Late Priabonian. Material: This species is only known from its type locality. Etymology: sculpturata refers to the quite unusual (for Achatina) teleoconch sculpture of this new species. Diagnosis: A medium sized fossil species of Achatina LAMARCK, 1799, with a peculiar teleoconch pattern of axial riblets and a sutural cord. Description: Shell medium sized, fusiform; protoconch comparatively small (only preserved as a stone core); teleoconch of ca. 7 whorls; whorls only slightly rounded, with a sculpture of fine axial ribs running over the complete whorl, ribs usually granular; suture moderately deep, strongly reinforced by a subsutural cord; ribs do not fuse with the cord; aperture obliquely lunulate, narrow, lower part of columella not preserved. Measurements: Holotype (Fig. 15a): H = 66.9 mm; Wh > 7. Remarks: So far, this species is only recorded from Wadi Darbat, where it occurs sympatrically with Limicolaria omanensis sp. nov. Even juvenile or subadult specimens of both species can be separated by the size of the protoconch (larger in A. sculpturata sp. nov.), the more slender upper teleoconch of L. omanensis sp. nov., and the smaller size of adult specimens. It is quite interesting to see the similarity in the surface sculpture, but the formation of the subsutural cord also helps to differentiate the two species. This new species is here attributed to Achatina and not Archachatina ALBERS, 1850 because of the relatively small size of the protoconch of A. sculpturata sp. nov.Published as part of Neubert, Eike & Damme, Dirk van, 2012, Palaeogene continental molluscs of Oman, pp. 1-28 in Contributions to Natural History 20 on pages 15-16, DOI: 10.5169/seals-787080, http://zenodo.org/record/583854
Helix borealis sensu Neubert 2014
No full textAPPENDIX 2. SYSTEMATICS, DISTRIBUTION, VARIABILITY AND ECOLOGY OF HELIX BOREALIS Helix borealis is generally poorly known, including conchological variability and its potential taxonomic significance. Most of the published accounts are in taxonomic compilations, often repeating earlier information, supplemented by faunistic data (see below for an overview of the literature). The biology and ecology of this taxon has been mostly neglected. Notable exceptions to this pattern are Hesse (1920), providing information on soft body morphology, and Welter-Schultes (1998a), who discussed its phenology and past distribution in Crete and on nearby islands. Kobelt (1895) distinguished, besides typical H. borealis, two more Greek taxa currently considered its synonyms. According to his description, Helix thiesseana Kobelt, 1878, described from Evvia, should have a more globular shell with darker palatal callus than the nominotypical form and almost missing spiral sculpture. The name H. thiesseana has been sometimes used not only for populations from Evvia, but also for individuals with darker apertures from the Peloponnese peninsula. Helix aetolica Kobelt, 1892 from Aetolia, western Greece (name invalid due to primary homonymy), should be larger with broader shell, darker coloration and less developed spiral sculpture than the nominotypical subspecies. The Turkish populations were never formally described. SYNONYMY OF HELIX BOREALIS Helix cincta – d’Audebard de Férussac AEJPJF, 1821– 1822: 29 (quarto edition) [partim: La Gréce, l’Archipel; l’ile de Zante] Helix cincta – Deshayes, 1835: 160 [partim: de Morée] Helix ambigua Mousson, 1859: 15, non Helix ambigua Linnaeus, 1758 (presently Fossarus ambiguus) [de la Grèce et de la Thessalie …de Corfou et de Céfalonie se retrouve avec toutes ses particularités sur toute la côte de l’Epire, tant à Sayades qua’à Prevesa] Helix ambigua var. borealis Mousson, 1859: 16 [Ile de Corfou…das les broussailles des rochers de la citadelle] Helix cyrtolena Bourguignat, 1860: 165 [nom. nov. for Helix ambigua Mousson, 1859] Helix (Pomatia) Thiesseana Kobelt, 1878: 320 [bei Chalcis auf Euböa] Helix Thiesseana – Kobelt W, 1879–80: 1, pl. 179, figs 1805–1806 [bei Chalcis auf Euböa] Helix cincta – Westerlund & Blanc, 1879: 79 [Pylos à Navarin, Pyrgos en Elide et dans l’Arcadie] Helix cincta Var. ambigua – Westerlund & Blanc, 1879: 79 [Iles de Céfalonie et d’Ithaque] Helix thiesseana – Westerlund & Blanc, 1879: 80 [Ile d’Eubée partie boréale] Helix Thiesseana – Godet, 1880: 25 [Chalcis (Euboea)] Helix ambigua – Hesse, 1882: 322 [auf Corfu an der strasse nach Castrades, und auf Zante an der Citadelle] Helix (Helicogena) ambigua – Boettger, 1883: 317 [Corfu] Helix (Helicogena) ambigua var. Thiesseae – Boettger, 1883: 329 [Patras; incorrect subsequent spelling of Helix thiesseana Kobelt, 1878] Helix (Helicogena) ambigua var. Thiesseae – Boettger, 1885: 118 [Achaia, Santameri] Helix [Pomatia] ambigua – Tryon & Pilsbry, 1888: 244, pl. 69, fig. 30 [Corfu, Cephalonia] H e l i x [Po m a t i a] a m b i g u a Va r. t h i e s s e a n a – Tryon & Pilsbry, 1888: 244, pl. 69, fig. 31 [Achaia; Chalcis, Euboea] Helix ambigua – Westerlund, 1889: 458 [Griechenland auf Corfu, Cephalonia, Zante, Ithaka]. Helix ambigua Forma clathrata Westerlund, 1889: 459 [Corfu u. Epirus] Helix thiesseana – Westerlund, 1889: 459 [Griechenland bei Chalkis auf Euboea]. Helix (Pomatia) ambigua – Kobelt W, 1891–92: 24, pl. 127, fig. 766 [in Griechenland und Epirus, sowie auf den jonischen Inseln] Helix (Pomatia) ambigua var. aetolica Kobelt W, 1891 –92: 106, pl. 146, figs. 936–937, non Helix (Macularia) Codringtoni var. Aetolica O. Boettger, 1888 (currently Codringtonia parnassia Roth, 1855) [Vrachori in Aetolien; on the plate erroneously labelled as Helix ambigua var. acarnanica] Helix ambigua – Schuberth, 1892: 51, pl. 5, fig. 18 [Corfu] Helix (Pomatia) ambigua – Kobelt W, 1893–97: 778, pl. 215, figs 1–2 [auf der jonischen Inseln, in Epirus und Nordgriechenland] Helix (Pomatia) ambigua var. aetolica – Kobelt W, 1893–97: 778, pl. 215, figs 2 [Vrachori] Helix (Pomatia) thiesseana – Kobelt W, 1893–97: 779, pl. 215, figs 3–4 [bei Chalkis auf Euböa] Helix (Pomatia) thiesseana – Sturany, 1902: 405 [Kalavryta, 800 m Höhe] Helix (Helicogena) ambigua – Kobelt W, 1902–06: 117, pl. 323, figs 1–4 Helix (Helicogena) ambigua thiesseana – Kobelt W, 1902–06: 118, pl. 215, figs 3–4 Helix (Pomatia) ambigua – Sangiorgi, 1903: 94 [Cefalonia, comune] Helix (Helicogena) ambigua thiesseana – Hesse, 1920: 183, pl. 654, figs 6–7 [Patras, Cerigo] Helix (Helicogena) ambigua – Hesse 1915-1920: 251 [Griechenland, Jon. Inseln, Kreta] Helicogena cincta subsp. ambigua – Käufel, 1930: 185 [Korfu, Levkas, Kephalonia] Helix cincta Rasse ambigua – Knipper, 1939: 369 Helix (Helicogena) cincta ambigua – Käufel & Fuchs, 1941: 201 [Zante: Maries, Keri, Skopos] Helix cincta ambigua – Zilch, 1952: 150 Helix (cincta thiesseana) – Zilch, 1952: 150 Helix cincta ambigua – Klemm, 1962: 255 [Levkas: Frini, Olivenhain] Helix (Helix) cincta ambigua – Rähle, 1980: 218 [Kephallinia, Zakynthos] Helix (Helix) cincta ambigua – Liebegott, 1986: 22 [Skopelos, Kira Panagia, Giura, Piperi] Helix cincta ambigua – Rähle, 1986: 6 [Ithaki] Helix (Helix) cincta borealis – Hausdorf, 1993: 45 Helx (Helix) cincta ambigua – Frank, 1997: 141 Helix cincta – Facorellis et al., 1998: 965 [mesolithic: Gioura] Helix (Helix) cincta – Welter-Schultes, 1998a: 100 [Crete: Anopoli, Alikampos; Gavdos, Gavdopoula] Helix cincta borealis – Neubert et al., 2000: 113 [Turkey: between Kaş and Demre] Helix cincta – Triantis et al., 2008: 475 [island group of Skyros] Helix cincta – Welter-Schultes, 2012: 611 [partim] Helix cincta cincta – Psonis et al., 2015: 383 [partim: Crete: Anopoli, Alikampos; Skyros; Peloponnese: Skollis mountain; Kerkyra: Pantokratoras mountain] Helix borealis – Neubert, 2014: 98 Helix borealis – Korábek et al., 2015 Helix borealis – Neubert & Korábek, 2015 DISTRIBUTION OF HELIX BOREALIS Helix borealis has a fragmented distribution. Its main range lies in the Peloponnese, south-western Pindus and the Ionian coast and Islands. On Evvia it is restricted to the north of the island (Neubert, 2014), unless it also lives near Chalkis, as stated in the original description (Kobelt, 1878). It was collected live on Skopelos and Skyros in the northern Sporades. Liebegott (1986) reports it only subfossil from Kyra Panagia, Gioura and Piperi in the northern Sporades; also Facorellis et al. (1998) refers to old shells (older than 7700 BC) from Gioura. On Crete, the species is apparently rare; only two confirmed localities and one probable were reported (Welter-Schultes, 1998a; Psonis et al., 2015). On the islands of Gavdos and Gavdopoula, south of Crete, it is most likely extinct. Shells dated to c. 6000–25 000 BC by radiocarbon analysis demonstrate the autochthonous origin of the species on these islands. However, they also indicate that the species may have been extinct for a long time already (Welter-Schultes, 1998a). In Anatolia, the distribution is broader than indicated by Neubert (2014). The species has been found in the province of Antalya between Kaş, Finike and Kemer (Neubert et al., 2000; own data); the known sites are listed in Table 2. PHENOTYPIC DIVERSITY OF H. BOREALIS The variation in conchological characters exhibits some geographic structure, which can be partly identified with the taxa distinguished by Kobelt (1895), partly the varieties have not been formally described. On Corfu and in the vicinity of Igoumenitsa lives a form identifiable with typical H. borealis (Supporting Information, Fig. S1D). Usually, the three upper bands are separated and well visible on the top of the shell, and the aperture has an ochre, rather than brown, colour. Towards the south (Acarnania and the islands of Lefkada, Kefalonia, Zakynthos) the shell colour is often pale without bands, but with a slightly darker upper half of the shell (Fig. 1C; Supporting Information, Fig. S1E). The colour of the aperture is similar and the coloration is often well developed only on the palatum and upper columella. These two forms were not distinguished from each other by the mitochondrial phylogeny, but together form a distinctive clade sister to the next form (Fig. 3). Snails similar to the syntypes of H. aetolica live in the northern Peloponnese, Aetolia, Evrytania, and marginally also in western Thessaly (Fig. 1E; Supporting Information, Fig. S1F). They usually have a regularly rounded shell with developed, but often inconspicuous, bands. The upper three usually fuse and their colour does not contrast much with that of the background. The aperture margins are completely dark-coloured. Younger individuals are sometimes covered by brown periostracum, which peels off rapidly, but the periostracum seems to be well developed only at more humid sites. Spiral sculpture varies but is often developed and relatively coarse. To the south of the Peloponnese, the shell surface coloration is often paler, with the background more whitish, and there is a tendency to have better separated and more contrasting bands (Supporting Information, Fig. S1G). However, the bands may also be reduced (Fig. 1D; Supporting Information, Fig. S1H). This and the previous form are not clearly separable and there are intermediates, but there is also a corresponding phylogenetic south–north divide (Fig. 4). Populations from Evvia (Fig. 1B; Supporting Information, Fig. S1B) are characterized by pale shells with completely reduced or highly vestigial banding; aperture margins are dark. The upper half of the shell is usually slightly darker than the lower half. The shells often lack spiral sculpture. Columella and aperture margins are relatively slim. This form corresponds fully to H. thiesseana. The analysed individual from Skopelos island (north of Evvia) was also of this type. The examined shells from Crete (Supporting Information, Fig. S1C) were small (around 3 cm), had a dark aperture and pale, but developed, banding and vestigial spiral sculpture. The Turkish populations (Supporting Information, Fig. S1A) are similar to H. thiesseana, and most of the differences may stem from differences in size. The shells are smaller, more compact, and with a smoother surface and finer transverse ribs. Also, unlike H. thiesseana, the Turkish snails often have narrow brown longitudinal bands on the older whorls. Typically, the middle band is the darkest one and is aligned with the suture. The foot is greyish brown with darker, grey or brown back (Fig. 1). The morphology of the genital organs was described by Hesse (1915–20: 183, pl. 654) from specimens from Patra and Kythira Island. Earlier, Schuberth (1892: 51) mentioned a specimen from Corfu as having a short stem of mucous glands and a curved love dart. Neubert (2014: 101) dissected an individual from south-western Anatolia. We examined three individuals from Evvia, 12 from six localities of the ‘ H. aetolica ’ morphotype, two individuals from Kefalonia and one typical H. borealis from Corfu. The genital system (Supporting Information, Fig. S2) does not differ substantially from that of related species (Neubert, 2014) nor are there consistent differences between mitochondrial clades. Short and weakly ramified mucous glands are characteristic. They are usually markedly shorter than the dart sac, but may also be as long as the sac. The love dart is curved towards its tip, with two high and sharp blades in the plane of the curve and two low blunt blades on the sides (the state is unknown for the Cretan-Turkish lineage). The diverticulum branches off in the proximal third to half of the combined pedunculus and bursa stem length. It is usually thick, but its length varies greatly from short (Supporting Information, Fig. S2E, individuals from a locality near Kalavryta, Peloponnese) to almost reaching the length of the bursa stem; sometimes, it is aligned with the bursa stem. The interior of the penis (Supporting Information, Fig. S3) also does not provide characters to differentiate between the H. borealis clades. The atrial stimulator is a knob of varying size. ECOLOGY OF HELIX BOREALIS The habitats where we found H. borealis varied greatly. On Evvia, the snails were attached to high limestone cliffs. Near Sparti, living specimens were also found on bare exposed limestone rocks. In the ruins of ancient Messene, we found it in the grass between the remains of the buildings. In the western Peloponnese, it is often found on Plio-Pleistocene sand and gravel deposits; on this substrate, we found shells on margins of pine forests. On the western coast, we found it in numbers on sand dunes covered with shrubs, a few hundred meters from the shore. Individuals of the ‘ H. aetolica ’ form with closely related haplotypes were found in a grazed phrygana at low elevation (Supporting Information, Fig. S4A), fir growths near Karpenisi at c. 1200 m a.s.l. (Supporting Information, Fig. S4B), and even at a small junk heap under Platanus L. trees in a village. In the north, the species is not limited to limestone. The phenology of the species likely strongly differs between regions. In the south, it is already largely inactive, at least by mid-April, in contrast to the northern part of the range in the mountains in Aetolia. Welter-Schultes (1998a) reports that on Crete the species allegedly emerges after the first October or November rains, only to disappear a few days later. Although there seems to be substantial plasticity, individual lineages may be more restricted in their tolerances. In fact, broadly tolerant is the ‘ H. aetolica ’ form from Peloponnese, Aetolia-Acarnania, Phocis and Evrytania, which appears common in parts of its range. Some other lineages, such as ‘ H. thiesseana ’ and the Cretan lineage, have restricted distributions and probably narrower (realized) niches. At several sites from Lefkada to the Albanian frontier, we have found only old-looking empty shells in April 2016, but it is impossible to say whether this reflects the season or a recent decline. It is also well possible that most of the mortality occurs when the snails are buried in the soil.Published as part of Korábek, Ondřej, Kosová, Tereza, Dolejš, Petr, Petrusek, Adam, Neubert, Eike & Juřičková, Lucie, 2021, Geographic isolation and human-assisted dispersal in land snails: a Mediterranean story of Helix borealis and its relatives (Gastropoda: Stylommatophora: Helicidae), pp. 1310-1335 in Zoological Journal of the Linnean Society 193 (4) on pages 1332-1335, DOI: 10.1093/zoolinnean/zlaa186, http://zenodo.org/record/576147
Cerastus pseudoena Neubert & Damme 2012, sp. nov.
No full textCerastus pseudoena sp. nov. (Fig. 16) Type specimens: Holotype NMBE 5018985. Type locality: Wadi Darbat, Dhofar, Oman. Stratum typicum: Paludal biomicritic limestones of the Zalumah Formation. Age: Late Priabonian. Material: This species is only represented by the holotype specimen. Etymology: pseudoena refers to the superficial similarity of this species with the Modern European enid species Ena montana (DRAPARNAUD, 1801). Diagnosis: A small species of Cerastidae with a unique formation of aperture, slight ribbing pattern on teleoconch whorls, and partly obscured umbilicus. Description: Shell slender, turreted; protoconch small, obtuse (not preserved as shell); upper teleoconch whorls elongate conical, last three whorls more rapidly increasing; a fine pattern of axial riblets covering the whorls (only partly preserved, Fig. 16b); aperture elongate oval, columellar part triangular, broad, peristomial rim slightly reinforced by lip formation, somewhat flared; umbilicus open, partly obscured by triangular columellar shield. Measurements: Holotype (Fig. 16): H = 13.78 mm; Wh > 8. Remarks: This new species is placed in the family Cerastidae, because it matches very well the enoid shell form of most of the Modern species in this family. The correct separation between Cerastidae and Enidae is based on several anatomical details (Mordan 1992). However, all cerastid species recorded from the Arabian peninsula share the shell morphological detail of shells that are ribbed on the upper teleoconch, at least. This holds also true for C. pseudoena sp. nov., which thus supports its affiliation to that family. It is described under the genus Cerastus ALBERS, 1860, because this genus has a long-lasting history as suggested by its distribution that ranges from Ethiopia via the southwestern Arabian Peninsula to northwestern India. Cerastus girwanensis CONNOLLY, 1941, a Modern endemic species from the Southwest of Saudi Arabia is shown here (Fig. 17) to facilitate comparison.Published as part of Neubert, Eike & Damme, Dirk van, 2012, Palaeogene continental molluscs of Oman, pp. 1-28 in Contributions to Natural History 20 on pages 16-18, DOI: 10.5169/seals-787080, http://zenodo.org/record/583854
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