Cyathophyllidae Dana, 1846

Ma, Xue-Ping, Sun, Yuan-Lin, Hao, Wei-Cheng & Liao, Wei-Hua, 2002, Rugose corals and brachiopods across the Frasnian- Famennian boundary in central Hunan, South China, Acta Palaeontologica Polonica 47 (2), pp. 373-396 : 381-382

Family Cyathophyllidae Dana, 1846 Genus Sinodisphyllum Sun, 1958

Type species: Disphyllum (Sinodisphyllum) variabile Sun, 1958 ; Lungkouchung Member , Shetienchiao Formation (Frasnian); Xiangxiang, Hunan, China .

Emended diagnosis.—Solitary charactophyllid coral. Septal arrangement radial, septa smooth without carinae; major septa long, showing weak to moderate peripheral dilation, tapering gradually towards corallum axis; minor septa distinct, generally as long as width of dissepimentarium. Fossula absent. Trabeculae of Charactophyllum − type. Dissepimentarium with two to five rows of inclined small vesicles; tabularium with a variable arrangement of complete tabulae and/or tabellae, which normally are split periaxially.

Remarks.— Sun (1958) erected the new subgenus Disphyllum (Sinodisphyllum) . Since then, its systematic status has been questioned and remains uncertain ( Liao 1996). In fact, the significant difference is that Sinodisphyllum is solitary rather than fasciculate.

Fontaine (1961) considered Sinodisphyllum invalid because of its inadequate description. For that reason, Strusz (1965) agreed with Fontaine’s idea that Sinodisphyllum was a senior synonym of Mansuyphyllum . Pedder (1965) proposed that Sinodisphyllum Sun should be considered to be a synonym of Mictophyllum Lang and Smith. Moreover , he also considered that the type species of Sinodisphyllum ( Sinodisphyllum variable Sun ) was a better representative of Mictophyllum than the type species of Mictophyllum selected by the original authors of the genus. He believed that there is a trend towards suppression of the minor septa and development of a herringbone dissepimentarium. Mictophyllum nobile is almost devoid of minor septa and represents a form very near the end of this trend. He noted that the trabeculae of Sinodisphyllum are disphyllid with relatively small but numerous dissepiments that are commonly inosculate. The tabulae may be short or long in longitudinal section and peripherally may be downturned, upturned or simply abut against adjacent tabula or dissepiments ( Pedder 1965: 202–203).

However, other researchers ( Liao 1977; Liao and Birenheide 1989; McLean 1993; Wang 1995) have considered Sinodisphyllum to be valid. Liao and Birenheide (1989) regarded Sinodisphyllum as a charactophyllid, characterized by long, thin tapering projections. They proposed that Mansuyphyllum Fontaine, 1961 and Aristophyllum Bulvanker et al., 1975 are junior synonyms of Sinodisphyllum . They also argued that some Russian species assigned to Campophyllum ( C. litvinovitshae Soshkina, 1949 ) should also belong to Sinodisphyllum . Wang (1995) claimed that the trabeculae of Sinodisphyllum are disphyllid, and the higher matching coefficient between Sinodisphyllum and Pseudozaphrentis is the result of adaptive convergence.

Occurrence.—South China and Russian platforms; late Givetian to Frasnian.