Elliptoglossa polonica, Holmer & Biernat, 2002
publication ID |
https://doi.org/ 10.13140/rg.2.1.3543.9120 |
persistent identifier |
https://treatment.plazi.org/id/FB5C1130-FFBA-5933-FCB4-D78209FCF816 |
treatment provided by |
Felipe |
scientific name |
Elliptoglossa polonica |
status |
sp. nov. |
Elliptoglossa polonica sp. nov.
Fig. 2 View Fig .
Schmidtites obtusus ( Mickwitz, 1896) ; Biernat 1973: 54, pl. 1: 1–3,
fig. 3.
Elliptoglossa sp. ; Bednarczyk and Biernat 1978: 297.
Holotype: RM Br133769, ventral valve (W = 0.56, L = 0.78, WI = 0.13, LI = 0.04).
Type locality: Wysoczki. Holy Cross Mountains, Poland.
Type horizon: Tremadoc chalcedonites.
Derivation of name: After the occurrence in Poland.
Material.—Total of 35 dorsal and 16 ventral valves. Figured ventral valves: RM Br133770 (W = 0.53, L = 0.78, WI = 0.13, LI = 0.04), RM Br133771 (W = 0.63, L = 0.92, WI = 0.16, LI = 0.07), RM Br133772 (W = 0.48, L = 0.84, WI = 0.11, LI = 0.06); dorsal valves: RM Br133767 (W = 0.60, L = 0.82), RM Br133768 (W = 0.62, L = 0.94), RM Br133773.
Diagnosis.—Shell elongate oval to subcircular, about 140– 180% as long as wide. Ventral pseudointerareas vestigial, with flattened triangular posterior projection. Dorsal pseudointerarea completely reduced.
Description.—Shell elongate oval, close to equi−biconvex, 140–180% as long as wide (N = 6); both valves gently and evenly convex in lateral profile. Ventral pseudointerarea forming characteristic flattened, narrow, undivided plate with posterior projection, occupying 23–25% of total valve width (N = 4) and only 5–8% of total valve length (N = 4); defined pedicle groove absent.
Dorsal valve lacking pseudointerarea, but with well defined marginal limbus, somewhat wider and higher posteriorly. Larval shell of both valves close to circular, around 0.2–0.3 mm wide and usually somewhat elongate.
Internal characters of both valves not impressed.
Discussion.— Biernat (1973) considered this taxon to represent juveniles of Schmidtites obtusus . However, following redescription of this taxon (e.g., Holmer and Popov 2000: 52, fig. 20: 4) it is clear that the Polish species is unrelated to Schmidtites . All characters (vestigial to completely absent pseudointerareas, lack of pedicle notch etc.) of the Polish taxon now indicate that it is a species of Elliptoglossa , as noted also by Bednarczyk and Biernat (1978) and Popov and Holmer (1994). E. polonica differs from all other species of the genus in having a vestigial ventral pseudointerarea forming a flattened, narrow, undivided plate with a posterior projection.
RM |
McGill University, Redpath Museum |
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
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Genus |
Elliptoglossa polonica
Holmer, Lars E. & Biernat, Gertruda 2002 |
Elliptoglossa sp.
Bednarczyk, W. & Biernat, G. 1978: 297 |
Schmidtites obtusus ( Mickwitz, 1896 )
Biernat, G. 1973: 54 |