Dalongicaepa Xiao and Suzuki

Xiao, Yifan, Suzuki, Noritoshi & He, Weihong, 2017, Applications and limitations of micro-XCT imaging in the studies of Permian radiolarians: A new genus with bi-polar main spines, Acta Palaeontologica Polonica 62 (3), pp. 647-656 : 648-650

Genus Dalongicaepa Xiao and Suzuki nov.

Type species: Dalongicaepa bipolaris Xiao and Suzuki gen. et sp. nov.; see below.

Species included: Pseudospongoprunum fontainei Sashida in Sashida et al., 2000.

Etymology: The combination of the strata name “Dalong” and the Latin caepa(-ae), onion (female noun).

Fig. 1. SEM micrographs (A–E, F 1, G 1, H 1) and micro-XCT cross-sectional images (F 2, F 3, G 2, G 3, H 2, H 3) of the polycystine radiolarian Dalongicaepa bipolaris Xiao and Suzuki gen. et sp. nov. from Changhsingian of the Rencunping section, South China. A. LGFEC SR 69-028 (paratype). B. LGFEC SR 69-090 . C. LGFEC SR 69-058 . D. LGFEC SR 69-091 . E. LGFEC SR 69-029 . F. LGFEC SR 69-062 . G. LGFEC SR 69-069 . H. LGFEC SR 69-057 (holotype). Different cross sections show clear concentric shells which are connected with radial beams (F 2, F 3, G 2, G 3, H 2, H 3). Scale bars 100 μm .

Diagnosis. —Spongy cortical shell of spherical to fusiform shape. Spongy tissue comprised with four to seven densely concentric shells. Central part of the cortical shell large spherical hollow without a latticed spherical shell. Two significant bi-polar spines are present: cylindrical and no blades. The proximal end of the spine is embedded into the densely concentric shell to connect with a thin cylindrical radial beam. The radial beam pierces through the inner large spherical hollow.

Remarks. —It is practically difficult to distinguish species of Dalongicaepa from any similar Permian species by the superficial appearance of specimens so that diagnosis characters can be examined in only broken specimens to an extent. All the known genera belonging to the Spongotortilispinidae are easily distinguished from this new genus in having needle-shaped bi-polar spines of circular cross section. Based on a breakage specimen of Dalongicaepa fontainei (Sashida in Sashida et al. 2000) illustrated by Feng et al. (2006: pl. 3: 6), this species belongs to Dalongicaepa Xiao and Suzuki gen. nov. because of the presence of a hollow space in the shell central part.

Stratigraphic and geographic range. —Upper Permian, South China.