Orecopia kadzielniae ( Gürich, 1896 ) Krawczyński, 2002

Krawczyński, Wojciech, 2002, Frasnian gastropod synecology and bio-events in the Dyminy reef complex of the Holy Cross Mountains, Poland, Acta Palaeontologica Polonica 47 (2), pp. 267-288 : 279-280

Orecopia kadzielniae ( Gürich, 1896) comb. nov.

Fig. 9A–I .

Pleurotomaria kadzielniae sp. nov.; Gürich 1896: 306, pl. 11: 3.

Straparollus (Straparollus) grabinensis sp. nov.; Karczewski 1989: 110, pl. 3: 1.

Holotype: MGUWr.1939.s ( Fig 9A, B ).

Type horizon and locality: Inactive quarry “Kadzielnia” (S part of

Kielce), set A, the Kadzielnia Member, early Frasnian.

Material.—Seven almost complete specimens, 3 internal moulds, 1 well preserved base as well as 6 fragments of the spire and 7 axial sections (M.G.U.Wr. 1939.s.; ZPAL Ga−VI/ 14, 16–22; GIUS 4−1021/Gr−153, 4−1024/Gr−156/2, 4−1028/ Gr−160/2, 4−1036/Gr−168, 4−1038–1043/Gr−170–175, 4−1045/ Gr−177/1, 4−1046/Gr−178, 4−1191/Gr−179, 4−1232/Ko−19, 4−1284/Gr−181).

Diagnosis.— Orecopia kadzielniae differs from O. mccoyi ( Walcott, 1884) by narrowly phaneromphalous base. O. cotei Pedder, 1966 has a carina at the periphery of the whorl. O. kirchholmiensis ( Keyserling,1846) hasmoreroundedwhorls and deeper sutures (see Chernychev 1884, 1887).

Description.—Large, high to low trochiform shell (maximum width 6.5 cm) with 6–7 whorls. First two whorls are flattened, next one abuts just below rounded periphery. Sutures are relatively flat. Ramp of the whorl is almost flat from suture to about half of the distance between suture and periphery. Wide sinus developed on the flat part of the ramp. Lower part of the ramp has a concave spiral belt with a breath equal to about ¼ of ramp width. Base is rounded, narrowly phaneromphalous. Columellar lip is strongly thickened. Umbilicus deep, surrouded by thick funicles. Growth lines form a wide, insignificant sinus on the base. Abandoned whorls are closed by septa (see Fig. 16A ). Aperture rounded, protoconch and outer lip are not preserved. Pleural angle decreasing during ontogenic development from 100 to 170°.

Variability.—The population of the species O. kadzielniae shows sufficiently high variability of the translation index H/W (0.45–0.85). It is caused by changes of the spire height and the relatively stable values of the apertural shape index Ha / Wa ( Fig. 13 ).

Remarks.—This species was described by Gürich (1896) from the Frasnian of Kadzielnia. The holotype of Pleurotomaria kadzielniae is an internal mould and it is housed in Gürich’s collection at the Geological Museum of Wrocław University. The concave belt at the ramp of the whorl had been identified as a selenizone in the original description. Shape and biometrical measures clearly indicate the resemblance of Gürich’s specimen to the specimens collected by the author at Grabina. That allows revision of this species.

Distribution.—Holy Cross Mountains: Kadzielnia, set A(the Kadzielnia Member), Kowala, set A 2 and Grabina, set A(the upper Sitkówka Beds; from early to middle Frasnian).

Figures

Fig.9. Orecopia kadzielniae (Gürich,1896)comb.nov.in Kowalatrochus sanctacrucensis associationfromlowerandupperSitkówkaBeds(earlyandmiddle Frasnian). A, B. Apertural and apical view of internal mould with fragmentary preserved shell from the original Gürich’s collection, Kadzielnia, set A, holotype MGUWr.1939.s. C. Axial section with visible funicles on umbilical wall, GIUS 4−1284/Gr−181. D, E. Apertural and basal view of shell with well preserved basal ornamentation, GIUS 4−1232/Ko−19. F, G. Apertural and apical view of shell with well preserved growth lines, GIUS 4−1041/Gr−173. H. Axial section with poorly preserved shell, GIUS 4−1045/Gr−177/1. I. Apertural view with fragmentary preserved shell, GIUS 4−1191/Gr−179. A–C, F–I. Grabina, set A; natural size. D, E. Kowala, set A2, × 2.

Fig. 16. Middle and late Frasnian limestones of the upper Sitkówka Beds and of the Detrital Beds from Grabina. A. Stromatoporoid−coral floatstone with amphiporoids (a) and the large gastropod Orecopia kadzielniae (Gürich, 1896) comb. nov. (O). Geopetal structure in the last whorl of shell and septation of the spire are visible, GIUS 4−1510/Gr−182, set A. B. Stachyodes (S)–Renalcis (R) bafflestone from a giant colony, set B, GIUS 4−1511/Gr−183. C. Coral rudstone with massive (mr) and branched (br) rugosans, branched tabulates (bt), brachiopods (b), and gastropods (g), set C, GIUS 4−1512/Gr−184. Scale bars 1 cm.

Fig. 13. Distribution of translation (H/W) and of apertural shape (Ha/Wa) indexes of Orecopia kadzielniae (Gürich, 1896) comb. nov. from the early and middle Frasnian of the upper Sitkówka Beds.