Wang et al.—Silurian amplexoid rugose corals from South China 92(6):982–1004


Remarks.—When describing this species, Cao (1975) did not provide information about its septal nature and septal micro- structure. Both features are diagnostically important and there- fore are included in the revised description. This taxon was originally considered as a subspecies of


Pilophyllia tenuiseptata by Cao (1975, p. 185), who stated that it differed from the latter “in having irregular length of extremely thin, and curved major septa, and having complete and more widely spaced tabulae.” Further, illustrations of its holotype (Fig. 15.4− 15.6) clearly show that it has wedge- shaped rhabdacanthine septa. This contrasts strongly with those in P. tenuiseptata, which appear to be entirely composed of lamellar stereomes. Considering these differences, this sub- species is regarded herein as unrelated to Pilophyllia, and is reassigned as a species of the new genus Neopilophyllia. Neopilophyllia irregularis is represented only by its


holotype at present. A specimen, illustrated as Pilophyllia tenuiseptata irregularis by Wang et al. (1986, pl. 2, figs. 2a −c), is unlikely to be a representative of N. irregularis, and should probably be transferred to P. tenuiseptata because it has closely spaced tabulae and lacks wedge-shaped rhabdacanths character- istic of Neopilophyllia n. gen.


Neopilophyllia ephippia (Cao, 1975) Figure 16


v*1975 Ningqiangophyllum ephippium Cao, p. 187, pl. 40, fig. 1a− c.


?1978 1986


Pilophyllia ephippia; He, p. 118, pl. 59, fig. 4a, b.


Pilophyllia ephippta; Wang et al., pl. 1, fig. 4a− c, pl. 2, fig. 5.


Holotype.—XACGS-G74, with two transverse sections and one longitudinal section, middle Ningqiang Formation (middle Telychian), Dazhongba, Ningqiang County, Shanxi Province.


Diagnosis.—Neopilophyllia n. gen. with narrow peripheral stereozone and commonly short major septa throughout growth. Tabulae complete, widely spaced.


Description.—Coralla solitary, cylindrical, medium to large. Number of major septa 41 at 32mm corallum diameter in holotype, 44 at 26mm in other examined specimen. Peripheral stereozone composed of thick minor septa and thickened per- ipheral ends of major septa; narrow, with width generally < 7% of corallum radius. Major septa amplexoid, thin, generally straight; short, with length generally < 30%, rarely 57%, of corallum radius. Minor septa generally extending short distance beyond stereozone (Fig. 16.4− 16.6, 16.10). Cardinal fossula indistinct (Fig. 16.3, 16.7) to distinct (Fig. 16.1, 16.11); when present, small, elongate, containing long cardinal septum. Tra- beculae wedge-shaped, thick, of rhabdacanthine type (Fig. 16.4− 16.6, 16.9, 16.10), laterally continuous or separated by thin to thick layer of lamellar stereome. Tabulae complete, subhorizontal, or slightly arched with moderately concave cen- tral portion (Fig. 16.2, 16.8). Tabular spacing generally regular, with 4 tabulae in 5mm. Dissepiments absent. [Translated from Cao (1975, p. 187), with revisions based on our observations of holotype and one new specimen.]


1003


Materials.—In addition to the holotype, a new sectioned spe- cimen of this species (NIGP 166954), from the same horizon (middle Ningqiang Formation) at Erlangba of Ningqiang, Shanxi Province, was examined.


Remarks.—In describing the holotype, Cao (1975) did not men- tion whether the septa of this species are amplexoid; this feature is included in the revised description. In addition, tabulae are flatter (Fig. 16.8), and a thin lamellar stereome is present between rhab- dacanths in the peripheral stereozone throughout ontogeny (Fig. 16.9, 16.10). A further specimen referred to this species byWang et al. (1986, pl. 1, fig. 4a−c, pl. 2, fig. 5) fromthe same horizon and same locality as the holotype shows similar features. One specimen identified as Pilophyllia ephippia by He


(1978) is probably referable to this species based on its identical description and occurrence in the same horizon as that of holotype, but a definite identification needs confirmation of its septal microstructure. Neopilophyllia ephippia is clearly distinguishable from


other members of Neopilophyllia n. gen. by its distinctive narrow peripheral stereozone. It further differs from N. crassothecata in having smaller coralla and more widely spaced tabulae, and from N. irregularis in lacking longer major septa and more widely spaced tabulae.


Acknowledgments


We are grateful to Zhou Z.-Q. and Wang J. for access to the col- lections at Xi’an Center of Geological Survey, China Geological Survey, and to Zhang Z.-F. for assistance in taking photographs of some thin sections. We appreciate comments on an early draft of the manuscript by R. McLean, and also sincerely thank the reviewers, E. Kido and R. McLean, and the journal editors, E. Currano and R. Elias, for their incisive and helpful comments that improved the final version of the paper. Financial support for this study came from the National Natural Science Foundation of China (41602008, 41521061, and 41472006) and the State Key Laboratory of Palaeobiology and Stratigraphy. I. Percival pub- lishes with permission of the Executive Director of the Geological Survey of New South Wales.


References


Cao, X.D., 1975, [Rugosa], in Li, Y.X., Song, L.S., Zhou, Z.Q., Yang, J.Y., et al., eds., [Lower Palaeozoic Stratigraphy of the Western Part of Dabashan]: Beijing, Geological Publishing House, p. 179–195. (in Chinese).


Cao, X.D., and Lin, B.Y., 1982, [Rugosa], in Xi’an Institute of Geology and Mineral Resources, ed., [Palaeontological Atlas of Northwest China, Shaanxi-Gansu-Ningxia Volume, Part 1, Precambrian and Early Palaeo- zoic]: Beijing, Geological Publishing House, p. 12–50. (in Chinese).


Chapman, E.J., 1893, On the corals and coralliform types of Palaeozoic strata: Proceedings and Transactions of the Royal Society of Canada, v. 10, p. 39–47.


Chen, J.Q., Wang, X.L., and Wang, H.Z., 1997, On taxonomy of the family Amplexidae Chapman, 1893: Acta Palaeontologica Sinica, v. 36, no. 1, p. 42–51.


He, X.Y., and Tang, L., 2013, [Classification and evolutionary trends of Middle Ordovician to Silurian Rugosa from the Yangtze Region]: Acta Palaeonto- logica Sinica, v. 52, p. 35–50. (in Chinese with English abstract).


Ge, Z.Z., and Yu, C.M., 1974, [Silurian corals], in Nanjing Institute of Geology and Palaeontology, Academia Sinica, ed., [A Handbook of the Stratigraphy and Paleontology in Southwest China]: Beijing, Science Press, p. 165–173. (in Chinese).


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