Niutoushania chongqingensis Chen, 2005
publication ID |
https://doi.org/ 10.5281/zenodo.13620199 |
persistent identifier |
https://treatment.plazi.org/id/03C98792-D32F-230D-FCEB-FC17E28F2072 |
treatment provided by |
Felipe |
scientific name |
Niutoushania chongqingensis Chen |
status |
sp. nov. |
Niutoushania chongqingensis Chen sp. nov.
Figs. 12 View Fig , 13A, B View Fig .
Holotype: NMV P309641 About NMV .
Other material: Eight specimens; figured specimen: NMV P309641 About NMV .
Type locality: Daijiagou section, Beipei , Chongqing, South China.
Type horizon: 1 st member of the Lower Lungtan Formation , Wuchiapingian, Late Permian.
Derivation of the name: After Chongqing City, South China.
Diagnosis.—Large, subquadrate shells, with moderately deep corpus cavity, fine spines on ventral costae, and distinct brachial ridges. The new species shares similar in shell outline, concavo−convexity, ornamentation and internal structures with the type species Niutoushania niutoushanensis Liao, 1984 , but is distinguished from the latter by its larger size, a relatively shallower corpus cavity and more pronounced brachial scars.
Description.—Geniculate anteriorly; widest at hingeline; ears broad, triangular, inflated, projecting laterally. Ventral valve highly evenly convex, strongly curved longitudinally; beak stout, strongly incurved, overhanging hingeline; umbonal region slightly flattened medially, incurved posteriorly; lateral slopes steep; median sulcus broad, shallow but distinct. Dorsal valve concave to slightly flattened. External costae irregularly spaced, bifurcate, about 5–6 in 10 mm at midlength of shell, relatively finer on disc, broadening near anterior margin; coarse spines arranged in row along hinge margin, scattered on disc and ears; fine spines densely covering on costae; dorsal ornament similar to that of ventral valve. Ventral adductor scars elongate, highly raised, separated by low median ridge; diductor scars broad, fan−like, flabellate ( Fig. 12A View Fig ); cardinal process bilobed anteriorly, supported by a low, thin median septum; cardinal ridges extending laterally along hinge margins; dorsal adductor scars elongate, smooth, highly elevated; diductor scars strongly dendritic; brachial ridges hook−like, horizontally extending from median septum ( Fig. 12B View Fig ).
Remarks.—Beyond Niutoushania , the large−sized productid Tyloplecta yangtzeensis ( Chao, 1927) is also overall comparable with the new species, from which Chao’s species is distinguishable in having anteriorly broadened costae, fine capillae, and nodules on the ventral umbo.
NMV |
Museum Victoria |
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