We report two new three-dimensionally phosphatized microfossils, Cambrolongispina reticulata gen. et sp. nov. and Cambrolongispina glabra gen. et sp. nov., from the middle Cambrian （Series 3, Drumian Stage） at Wangc...We report two new three-dimensionally phosphatized microfossils, Cambrolongispina reticulata gen. et sp. nov. and Cambrolongispina glabra gen. et sp. nov., from the middle Cambrian （Series 3, Drumian Stage） at Wangcun, Yongshun County, western Hunan, South China. They are bivalved arthropods, with thin, pliable, originally chitinous or chitin-calcareous shields （c. 350-517 I1 m long）. The shields are equipped with a pair of antero-dorsal spines. The spines are internally hollow, varying in length from 1/2 of to as long as the shield length in C. reticulata, and uniformly longer than the shield length in C. glabra. The spines of C. reticulata are ornamented with a longitudinal row of conical or blade-shaped denticles along the posterior edge. Cambrolongispina lacks marginal rims, valve lobation and sulci which are diagnostic of the Bradoriida sensu stricto. It also lacks a donblure/duplicature characteristic of phosphatocopids and some bradoriids. It could be related to the Monasteriidae （which may belong to Bradoriida sensu lato）, both characterized by a pair of antero-dorsal spines. Cambrolongispina may have been meiofaunai detritus feeders that lived on or within sediments. The antero-dorsal spines may have been sensory organs to detect nearby predators. The posterior denticles on these spines might have facilitated the sensory function of the spines.展开更多
We describe new material of three-dimensionally phosphatized small shelly fossils Acanthocassis and Xinlispina gen.nov.from the Fortunian Stage（early Cambrian） of southern Shaanxi and northern Sichuan Provinces.The ...We describe new material of three-dimensionally phosphatized small shelly fossils Acanthocassis and Xinlispina gen.nov.from the Fortunian Stage（early Cambrian） of southern Shaanxi and northern Sichuan Provinces.The new materials allow description of the delicate morphology of these skeletons, and also their skeletogenesis.Acanthocassis and Xinlispina have comparable morphological features： a main branch and radially arranged sub-branches.They differ from each other in many details, e.g., the presence of a single central branch only in Xinlispina, and the presence of small nodes only in Acanthocassis.Acanthocassis cannot be a naked anthopolyp or hydropolyp because of the more-or-less stiffened cuticle and the absence of a mouth.Acanthocassisand Xinlispina differ from coeval sponge spicules and chancelloriid sclerites and rosettes of crossed pedicellariae of echinoderms, and might be cuticular ornaments of animals of unclear affinities.They occur in the first small shelly fossil assemblage zone, and could be adopted as auxiliary fossils for biostratigraphic correlation in southern China.展开更多
基金supported by the National Natural Science Foundation of China (41102003 and J1210006 to ZH41272011 to XS+3 种基金41372015 to DXP)State Key Laboratory of Palaeobiology and Stratigraphy,Nanjing Institute of Geology and Palaeontology,Chinese Academy of Sciences (20132107 to ZH103102 to DXP)the Research Fund for Doctoral Program of High Education (20060001059 to DXP)
文摘We report two new three-dimensionally phosphatized microfossils, Cambrolongispina reticulata gen. et sp. nov. and Cambrolongispina glabra gen. et sp. nov., from the middle Cambrian （Series 3, Drumian Stage） at Wangcun, Yongshun County, western Hunan, South China. They are bivalved arthropods, with thin, pliable, originally chitinous or chitin-calcareous shields （c. 350-517 I1 m long）. The shields are equipped with a pair of antero-dorsal spines. The spines are internally hollow, varying in length from 1/2 of to as long as the shield length in C. reticulata, and uniformly longer than the shield length in C. glabra. The spines of C. reticulata are ornamented with a longitudinal row of conical or blade-shaped denticles along the posterior edge. Cambrolongispina lacks marginal rims, valve lobation and sulci which are diagnostic of the Bradoriida sensu stricto. It also lacks a donblure/duplicature characteristic of phosphatocopids and some bradoriids. It could be related to the Monasteriidae （which may belong to Bradoriida sensu lato）, both characterized by a pair of antero-dorsal spines. Cambrolongispina may have been meiofaunai detritus feeders that lived on or within sediments. The antero-dorsal spines may have been sensory organs to detect nearby predators. The posterior denticles on these spines might have facilitated the sensory function of the spines.
基金supported by the National Natural Science Foundation of China (41072012 and 41102003)the State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (113115 and 20132107)+2 种基金the Key Project of Central University Fund (CHD2012ZD017)College Students’ Innovative Entrepreneurial Training Program (201410710144 and 201410710105)The Ninth "Challenge Cup" Competition of College Students’ Extracurricular Academic and Technological Achievements, Chang’an University
文摘We describe new material of three-dimensionally phosphatized small shelly fossils Acanthocassis and Xinlispina gen.nov.from the Fortunian Stage（early Cambrian） of southern Shaanxi and northern Sichuan Provinces.The new materials allow description of the delicate morphology of these skeletons, and also their skeletogenesis.Acanthocassis and Xinlispina have comparable morphological features： a main branch and radially arranged sub-branches.They differ from each other in many details, e.g., the presence of a single central branch only in Xinlispina, and the presence of small nodes only in Acanthocassis.Acanthocassis cannot be a naked anthopolyp or hydropolyp because of the more-or-less stiffened cuticle and the absence of a mouth.Acanthocassisand Xinlispina differ from coeval sponge spicules and chancelloriid sclerites and rosettes of crossed pedicellariae of echinoderms, and might be cuticular ornaments of animals of unclear affinities.They occur in the first small shelly fossil assemblage zone, and could be adopted as auxiliary fossils for biostratigraphic correlation in southern China.
