Six silicified left valves including one nearly complete were obtained from acid residues of two samples collected from the Early Carboniferous Muhua Formation in Guizhou Province, China. The Chinese specimens have reticulate ornament and a large asymmetrical aviculopectinid−type resilifer and are much like Girtypecten from Permian rocks in the United States. However, the Chinese material shows only unicostate radial ornament, whereas Girtypecten is multicostate. Thus, a new taxon Girtypecten (Sinopecten) newelli subgen. et sp. nov. is proposed. The conodont assemblage occurring with G. (Sinopecten) newelli dates the new scallop as Tournaisian (the conodont Lower Siphonodella crenulata Zone); this is the oldest known occurrence of Girtypecten.
A new genus Sinosaurichthys of the Saurichthyidae with three new species, S. longipectoralis, S. longimedialis, and S. minuta, are described and compared with Saurichthys. The new genus is represented by more than a hundred almost complete skeletons, collected from the strata corresponding to the Upper Member of the Guanling Formation (Pelsonian, Anisian, Middle Triassic) of two localities: Yangjuan of Panxian County, Guizhou Province, and Dawazi of Luoping, Yunnan Province, China. Sinosaurichthys differs from Saurichthys in having an unusual dermal pectoral girdle, high insertion of pectoral fin, relatively dorsally positioned axial skeleton in the abdominal region, and in the absence of branchiostegal rays. These differences are supposed to reflect the different life styles between the two genera. Sinosaurichthys, like the extant needlefish, probably has a better ability for cruising in surface water than Saurichthys. In addition, these species of Sinosaurichthys are compared, and their morphological differences also probably reflect individual adaptations for different habitats at the two localities.
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