Episcomitra Monterosato, 1917

Harzhauser, Mathias & Landau, Bernard, 2021, The Mitridae (Gastropoda: Neogastropoda) of the Miocene Paratethys Sea, Zootaxa 4983 (3), pp. 1-72 : 7-9

publication ID

https://doi.org/ 10.11646/zootaxa.4983.1.1

publication LSID

lsid:zoobank.org:pub:6A4778D6-195A-4AB1-AA1E-7D8000185B28

DOI

https://doi.org/10.5281/zenodo.5043998

persistent identifier

https://treatment.plazi.org/id/A82A87E9-8A10-3845-FF4D-F93FFA5EFEB8

treatment provided by

Plazi

scientific name

Episcomitra Monterosato, 1917
status

 

Genus Episcomitra Monterosato, 1917 View in CoL

Type species. Mitra zonata Marryat, 1818 View in CoL , by monotypy. Present-day, Mediterranean Sea.

Diagnosis. “ Shell small to large (15–110 mm), fusiform or elongate-fusiform, smooth, with well-developed periostracum. Protoconch large, paucispiral, cyrtoconoid, of about two smooth glossy convex whorls. Spire tall or rather low; suture impressed. Spire whorls evenly convex in outline, sculpture represented by fine, dense, collabral lines. Last adult whorl typically evenly convex with rather short siphonal canal bearing a distinct fasciole, separated from shell base by deep groove. Siphonal notch deep or rather shallow. Outer aperture lip evenly convex, or convex in its adapical portion and straight throughout most of its length. Inner aperture lip with four, fine, subequal columellar folds ” ( Fedosov et al., 2018: 38).

Discussion. Landau et al. (2013) proposed a strict generic concept within Mitridae , and restricted Mitra Lamarck, 1798 to Indo-Pacific species with barbed or crenulated outer lips. European Neogene and Recent Mediterranean species with smooth lips were placed in Episcomitra Monterosato, 1917 . This approach was generally confirmed by molecular data of Fedosov et al. (2018), although the Indo-Pacific “ Mitra ” turned out to be polyphyletic. Moreover, only two of the three Recent Mediterranean Mitridae are now placed in Episcomitra [ E. zonata ( Marryat, 1818) , E. cornicula ( Linnaeus, 1758) ], whereas molecular data require the third species “ Mitra cornea Lamarck, 1811 to be placed in Isara H. & A. Adams, 1853. Fedosov et al. (2018: 291) pointed out that “ there are no morphological characters that substantially differentiate the two genera ”. Therefore, for pragmatic reasons we place most the species discussed herein in Episcomitra , except for Mitra hoernesi Mayer, 1864 , which is morphologically extremely similar to Isara cornea . Morphometric data are given in Table 1 View TABLE 1 .

Present-day distribution. Mediterranean Sea and West Africa ( Fedosov et al. 2018).

Key to Episcomitra species in the Paratethys

1. Spiral sculpture present on later whorls.....................................................................2 Spiral sculpture restricted to early spire whorls and fasciole, or very faint on later whorls.............................5 Spiral sculpture absent, except over fasciole....................................................... E. praenigra

2. Spiral sculpture delicate................................................................................ 3 Spiral sculpture flattened bands.......................................................................... 4

3. Fine spiral sculpture on all surface.................................................................. E. bouei Fine View in CoL spiral sculpture restricted to subsutural area........................................... E. antibellardii View in CoL nov. sp.

4. Flat bands, narrow interspaces, shell biconic.......................................................... E. facilis Flat bands, narrow interspaces, shell fusiform.......................................... E. pseudoincognita View in CoL nov. sp. Faint grooves, subobsolete, shell biconic........................................................... E. brusinae Spirals View in CoL subobsolete mid-whorl on last whorl, shell shape columbellid............................ E. neubauer i nov. sp.

5. Shell large to moderately large........................................................................... 6 Shell medium to small................................................................................. 7

6. Shell large, slender, short aperture........................................................... E. missile View in CoL nov. sp.

7. Shell fusiform, moderately broad to moderately slender....................................................... 8 Shell medium-sized, tall and slender fusiform with tall spire............................................. E. hilberi Shell View in CoL small, tall and slender fusiform............................................................... E. pilsbryi View in CoL

8. Last whorl weakly shouldered, faint spirals................................................ E. leopoldiana View in CoL nov. sp. Last whorl not shouldered, no spiral sculpture, SL<30 mm .......................................... E. cochlearella Last View in CoL whorl not shouldered, no spiral sculpture, SL> 30 mm ............................................ E. friedbergi View in CoL

TABLE 1. Episcomitra species in the Paratethys: Morphometric data; aperture length (AL), aperture width (AW), ap- erture height (AH), breadth (SL/MD), apertural width (AL/AW), siphonal canal length (AH/S <2.1), moderately long (AH/S). For further explanation see Figure 2.

Species SL (mm) SL/MD AL/AW AH/S
  small SL <20.0 medium-sized 20-40 mod. large 40.1–60 large SL>60 broad SL/MD <2.5 mod. broad>2.5–3.0 mod. slender 3.1–3.5 slender>3.5 narrow AL/AW ≥ 5.8 mod. narrow <5.8–5.0 mod. wide <5.0–4.0 wide <4.0 long AH/S <2.1 mod. long 2.1–<2.5 mod. short <2.5–2.9 short ≥ 3.0
E. antibellardiana nov. sp. medium-mod. mod. slender mod. width mod. long
E. bouei small mod. broad mod. narrow mod. short
E. cochlearella small-medium mod. broad mod. wide-wide mod. short
E. facilis small mod. broad mod. wide mod. long
E. hilberi medium slender wide mod. long
E. leopoldiana medium-mod. moderate moderate moderate
E. pilsbryi small mod. slender mod. wide moderate
E. praenigra mod. large mod. slender mod. wide mod. short
E. pseudoincognita nov. sp. small-medium mod. broad mod. wide mod. long
E. brusinae large mod. slender narrow mod. long
E. friedbergi small-medium mod. slender mod. wide-wide mod. short
E. missile nov. sp. large slender narrow short. mod.short
E. neubaueri nov. sp. medium mod. broad wide mod. short

Kingdom

Animalia

Phylum

Mollusca

Class

Gastropoda

Order

Neogastropoda

Family

Mitridae

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