Cirsotrema hornesi ( De Gregorio, 1889 )

Harzhauser, Mathias & Landau, Bernard M., 2025, The Epitoniidae (Gastropoda, Epitonioidea) of the Miocene Central Paratethys Sea-an overwhelming diversity, Zootaxa 5630 (1), pp. 1-142 : 43

publication ID	https://doi.org/10.11646/zootaxa.5630.1.1
publication LSID	lsid:zoobank.org:pub:89462472-D932-4255-880F-C6EF15220A31
persistent identifier	https://treatment.plazi.org/id/03D787A4-FFCF-FFCE-FF3F-FF2EFBAA908F
treatment provided by	Plazi
scientific name	Cirsotrema hornesi ( De Gregorio, 1889 )
status

Treatment

Cirsotrema hornesi ( De Gregorio, 1889)

Figs 15G–H View FIGURE 15 , 16A–F View FIGURE 16

Scalaria pumicea Brocc.—Hörnes 1856: 477 , pl. 46, figs 10a–b [non Cirsotrema pumicea ( Brocchi, 1814) View in CoL ].

[ Scalaria pumicea Brocc. ] Var. Hornesi —De Gregorio: 1889: 9 [nov. nom. pro Scalaria pumicea in Hörnes 1856: pl. 46, figs 10a–b].

[ Scalaria View in CoL ] C [irsotrema]. rusticum var. Hoernesi [sic] (De Greg.)— Sacco 1891: 53, pl. 2, fig. 35.

Scala (Cirsotrema) pumicea rustica Defr.— Strausz 1954: 19 , pl. 1, fig. 11.

C [irsotrema]. (C [irsotrema].) rusticum hörnesi [sic] (Greg.)— Sieber 1958: 129.

Cirsotrema View in CoL (s.s.) rusticum hoernesi [sic] De Gregorio, 1889 — Glibert 1962: 239.

Cirsotrema pumiceum ( Brocchi, 1814) View in CoL — Landau et al. 2013: 140, pl. 20, fig. 11 [non Cirsotrema pumiceum ( Brocchi, 1814) View in CoL ].

Type material. Holotype, NHMW 1851 View Materials /0013/0086, SL: 12.7 mm, MD: 5.2 mm, Steinabrunn ( Austria), illustrated in Hörnes (1856: pl. 46, figs 10a–b), Figs 15H View FIGURE 15 , 16A View FIGURE 16 1 –A View FIGURE 1 2 View FIGURE 2 .

Illustrated material. NHMW 1865/0001/0585a, SL: 14.4 mm, MD: 5.5 mm, Steinebrunn ( Austria), Figs 16B View FIGURE 16 1 –B View FIGURE 1 2 View FIGURE 2 . NHMW 1865/0001/0585b, SL: 12.5 mm, MD: 5.0 mm, Steinebrunn ( Austria), Figs 16C View FIGURE 16 1 –C View FIGURE 1 2 View FIGURE 2 . NHMW 1865/0001/0585c, SL: 12.9 mm, MD: 5.8 mm, Steinebrunn ( Austria), Figs 16D View FIGURE 16 1 –D View FIGURE 1 2 View FIGURE 2 . NHMW 2010/0004/0523b, SL: 16.2 mm, MD: 6.3 mm, Bad Vöslau ( Austria), Figs 15G View FIGURE 15 , 16E View FIGURE 16 1 –E View FIGURE 1 2 View FIGURE 2 . NHMW 1855/0045/0205, SL: 17.7 mm, MD: 6.7 mm, Steinebrunn ( Austria), Figs 16F View FIGURE 16 1 –F View FIGURE 1 2 View FIGURE 2 .

Additional material. 1 spec., NHMW 1859 View Materials /0027/0189, Gainfarn ( Austria) ; 10 spec., NHMW 1865 View Materials /0001/0585, Steinebrunn ( Austria) :

Revised description. Shell medium-sized, robust, moderately slender (apical angle ~22°), weakly coronate. Protoconch unknown. Teleoconch of about eight whorls. Early teleoconch whorls convex, slightly gradate, with narrow, close-set, moderately high varices. Later teleoconch whorls moderately convex, subcylindrical, with narrow, shallow, weakly concave subsutural ramp, distinctly angled shoulder, and periphery placed mid-whorl. Suture deeply impressed, fenestrate, almost fully obscured by varices. Sculpture of numerous, close-set, very broad, internally lamellose, weakly prosocline varices, not aligned axially, separated by narrow interspaces (~20: ~16/18: 18; partly amalgamated). Varices touching each other at level of spiral cords, resulting in punctate to fenestrate surface. Crests of varices with densely packed foliaceous laminae resulting in porous surface. Each whorl with three very prominent, broad, swollen varices with dense internal sculpture. Varices weakly coronate along shoulder on some specimens on last teleoconch whorls. Interspaces barely visible. Last whorl attaining 40% of total height. Last whorl with basal angulation, coinciding with very prominent peribasal cord, delimiting slightly concave basal disc, varices weakening on base. Fasciole short, broad with very prominent growth lines. Aperture circular. Columella concave. Outer lip strongly thickened by varix, basal lip broad. Columellar callus and parietal callus delicate. Peristome duplex. No umbilicus.

Discussion. Cirsotrema hornesi ( De Gregorio, 1889) is highly reminiscent of the Miocene to Recent Atlanto-Mediterranean Cirsotrema pumiceum ( Brocchi, 1814) , which differs in its more subcylindrical whorls, the subsutural shelf and angled shoulder, which gives it a slightly gradate appearance. In contrast to Cirsotrema hornesi the base of Cirsotrema pumiceum has a strongly angled base and wide basal disc. Subadult specimens of Cirsotrema hornesi , however, are almost indistinguishable from Cirsotrema pumiceum . Like the complex of large solid Cirsotrema species discussed under Cirsotrema crassicostatum (Deshayes, 1850) , the smaller Cirsotrema species similar to C. pumiceum also turn out to represent a species complex.

Paleoenvironment. Known from both shallow water and deep water settings.

Distribution in Central Paratethys. Badenian (Middle Miocene): Vienna Basin: Baden, Bad Vöslau, Steinebrunn, Gainfarn ( Austria) (Hörnes 1856; hoc opus).

Proto-Mediterranean Sea. Langhian (Middle Miocene): Colli Torinesi : Sciolze ( Italy) ( Sacco 1891). Serravallian (Middle Miocene): Karaman Basin: ( Turkey) ( Landau et al. 2013).