Pyramidaspirifer Ma and Day, 2000
publication ID |
https://doi.org/ 10.5281/zenodo.13742176 |
persistent identifier |
https://treatment.plazi.org/id/4836037D-D67D-6C55-FCF5-D5EBFDCBFA7F |
treatment provided by |
Felipe |
scientific name |
Pyramidaspirifer Ma and Day, 2000 |
status |
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Genus Pyramidaspirifer Ma and Day, 2000 Pyramidaspirifer cf. helenae ( Fenton, 1918)
Fig. 11H View Fig .
1918 cf. Spirifer cyrtinaformis helenae nov. var.; Fenton 1918: 216, pl. 6: 11–17.
1982 cf. Tenticospirifer cf. T. cyrtinaformis ( Hall and Whitfield, 1872) ; Cooper and Dutro 1982: 112, pl. 33: 9–15.
Material.—One poorly preserved, distorted specimen (sample QZQ4) from the basal part of the Qilijiang Formation in the Qiziqiao section.
Description.—Flank plications simple, with about 17 on each flank, diminishing in strength laterally; sinal plications also simple, except for the central one, which bifurcates and is slightly weaker, totally 8 in number anteriorly; sinus shallow but distinct, originating near posterior end, without primary plications; fold only appearing at mid−length, with weaker plications centrally, transitions between fold and flanks gradual, without a distinct delimiting furrow on each side. Discussion.—The nature of the fold and sinus (no primary plications in the sinus and no delimiting furrow on each side of fold) excludes it from the Cyrtospiriferidae (e.g., Tenticospirifer ). The shell is similar to North American Late Frasnian Pyramidaspirifer helenae ( Fenton, 1918) except that the Qiziqiao specimen has a more swollen ventral valve.
MA ET AL.—FRASNIAN BRACHIOPODS FROM SOUTH CHINA SHELF 807
5 mm
Pyramidaspirifer has only been recognized in the Late Frasnian of North America, and this extends its geographic distribution to South China.
Occurrence.—The present species occurs in Bed 20 of the Qiziqiao section of central Hunan, correlated with the lower part of the Early Palmatolepis rhenana Zone.
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