Szabó János szerk.: Fragmenta Mineralogica Et Palaentologica 26. 2008. (Budapest, 2008)

Shape — Moderately high, gradate shell with convex whorls represents this species. Angulation of ramp strongly rounded. Outer face of whorls wide and slighdy convex; selenizone runs on adapical half of this surface. Periphery rounded angular; base feebly convex and narrowly phanero­mphalous. No peristome part preserved. Sculpture — Single row of periodically repeated, slighdy opisthocline ridges formed between upper suture and abaxial edge of ramp. Unequally sized, irregularly undu­lating, dense spiral cords cover the whorls. Juvenile shell part has reticulate ornament of equally strong threads but col­labral ones fade away on subsequent whorls, where only growth-lines cross spiral cords. Remarks — The shape of the specimen is somewhat similar, but surely does not belong to "Trochotoma striatum HÖRNES, 1853" as the label in its box has suggested. This latter species has no ridges in the sculpture and has lower and less rapidly expanding whorls of different ornament. [The true, figured specimen was found in the collection of the GBa; see below as Peptomaria striata (HÖRNES, 1853)]. The single row of ridges on the ramp is a rather characteristic morphological element but the specific identification needs further studies. The shape resembles to that of Pleurotomaria eplenyensis n. sp., but it has two rows of much stronger, collabrally elongate ridges on the ramp and along the periphery, respectively. Bathrotomaria intermedia (MÜNSTER, 1844) bears also a comparable shell with a single row of ridges on the ramp, but its spiral cords are weaker, denser and of equal size; position of the selenizone coinciding just with the angula­tion of the whorls that distinguishes it from P. aff. eplenyensis, having selenizone on the outer face. Distribution — Schafberg (St. Wolfgang), Upper Pliensbachian. Figure 33 — Pleurotomaria aff. eplenyensis — Two lateral views to show shape and ornament of the available specimen, Xl. Pleurotomaria aff. anglica (SOWERBY, 1818) (Figure 34) aff. 1818: Trochus anglicus Sow. — S< »WERBY, p. 195, pi. 142. aff. 1853: Pleurotomaria anglica D'ORB. — D'ORBIGXV, p. 396, pi. 346. aff. 1858: Pleurotomaria anglica Sow . — QUENSTEDT, p. 82, pi. 10, fig. 9. 1861: Pleurotomaria anglica'Sow '. — STOLICZKA, p. 191, pi. 4, fig. 10. aff. 1894: Pleurotomaria anglica SOW. — PARONA, p. 162, pi. 6, figs 1-2. aff. 1907: Pleurotomaria anglica SOW. — SlEBERER, p. 14, pl. 1, fig. 3. aff. 1937: Pleurotomaria anglica Sow. — PCHELINCEV, p. 19, pl. 1, fig. 1. aff. 1964: Pleurotomaria anglica (Sow.) — SACCIII VlALLI, p. 4, pl. 1, figs 2 a-c. non 1980: Pleurotomaria (Pleurotomaria) anglica (Sow.) — SZABÓ, p. 57, pi. 2, fig. 5. Material — Most of the available specimens are badly damaged fragments (GBa 2008/69/44/1—17) Measurements H HL GBa 2008/69/44/1 **31 *17.5 HP *11 D *31 W *16 AA AL **73° Shape — Rather large species with gradate spire. Nanow ramp of low slope, being almost horizontal, abaxially bordered by rounded angulation. Outer face slightly convex, with broad feebly convex selenizone on its middle, rein­forced by strong median cord. Base convex, narrowly phaneromphalous. Outer lip rather strongly prosocline above selenizone. Inner lip, extending as rather large callus, partially overlaps base and umbilicus. Rim of umbilicus strongly rounded. Sculpture — Whorls, as well as base, covered by sparse, strong, undulating spiral cords. Collabral orna­ment consists of marked growth-lines, being prosocline abo\ r e selenizone, prosocyrt on outer face and opistho­cyrt on base. Lower edge of ramp bears characteristic nodes, being elongate orthocline way, i.e. crossing prosocline course of growth-lines. In post-juvenile growth stage, denser and collabrally elongate nodes develop also on periphery that fade out rapidly both ad- and abapically. Remarks — The shape of the Hierlatz Alpe speci-

Next

/
Thumbnails
Contents