Mooreocrinus liaoi sp. nov. (Crinoidea, Echinodermata) from the Pennsylvanian (Upper Carboniferous) Outangdi Formation in Zhejiang, South China Block

A new crinoid species of the Order Cladida, Mooreocrinus liaoi Mao and Li sp. nov., is described from the Pennsylvanian (Upper Carboniferous) Outangdi Formation in Jiangshan, Zhejiang Province, representing the first record of Mooreocrinus Wright and Strimple, 1945 in China. The presence of Mooreocrinus in the South China Block extends the palaeogeographical record of this genus and indicates it to be a cosmopolitan taxon. Three other ancient tectonically separated areas that are now combined into the modern China mass (Sibumasu, Junggar, North China) do not contain any record of Mooreocrinus. Overall, there is low biodiversity of the Late Palaeozoic crinoid faunas in the South China Block. Our new materials provide further evidence for diversity assessment of crinoid faunas in peri‐Gondwana blocks.

. Tectonic subsidence basins were formed and controlled by active faulting along the western margin of Cathaysian Land in the Carboniferous. Depositional successions of the Carboniferous are dominated by pebbles, sandstones, and siltstones sourced from erosion of the Cathaysian Land, mixed with a few carbonate beds of the Yejiatang and the overlying Outangdi formations (Hao, Nie, Rao, & Zhang, 2006).
The Carboniferous Outangdi Bed (nowadays Outangdi Formation) named by Lu, Mu, Hou, Zhang, and Liu (1955) in Jiangshan is composed of yellow siltstones intercalated with light grey thin-bedded nodular shelly limestones (Guo, 1994(Guo, , 2004Guo & Liang, 1993  extend well up into lateral walls; radials wider than long, distal edges curved sharply inward to form a large forefacet; three anal plates normal or in advanced arrangement with radianal tending to migrate to posterior position and right tube plate barely notching cup summit. Arms 10, recti-uniserial, broad in proximal region but tapering to narrow width before attaining midheight, pinnulate; primibrachs 1 axillary, wide, with sharply inwardly sloped proximal surface. Stem relatively small (Moore and Strimple in Moore & Teichert, 1978;Lane, 1964).
Remarks: This genus was originally proposed for the reception of species formerly assigned to the genus Dicromyocrinus (Lane, 1964), which typify Mooreocrinus in having uniserial low, rectangular brachials, while Dicromyocrinus has cuneate brachials. Mooreocrinus is typically of Moscovian age, with five species reported including (Mooreocrinus geminatus [Trautschold, 1879]; Mooreocrinus magdalenensis Strimple, 1975; Mooreocrinus mendesi (Lane, 1964); and The radial facets are large, plenary, as wide as the radials, with long, wide outer ligament areas that slope gently outward. The outer ligament furrow is deepest next to the outer marginal ridge; the transverse ridge is denticulate on both sides. The inner ligament area and muscle areas are not exposed.
Three anal plates are in primitive position. The radianal is large and elongated, quadrangular, oblique position, adjoined by C radial, BC and CD basals, secundanal, and tertanal, strongly convex longitudinally and gently convex transversely. Anal-X is also relatively large, gently convex, higher than wide, distal tip above radial summit, in contact with the radianal, posterior basal, and left-posterior radial.
Another anal plate is small and high, above and to the right of anal-X, distal half above radial summit. This third anal plate and the anal-X separate the left-posterior and right-posterior radials and extend above the radial circlet.
There are two arms to each ray, branching on IB rr1 which are axillary, large, wider than high, strongly convex transversely, gently convex longitudinally, and restricted in width just above the radials. in that it has a more globose cup, more convex cup plates, and more impressed sutures. M. liaoi sp. nov. is remarkably similar in size, shape, and ornamentation to M. wilhurnlooreocrinus wilburni Strimple and Watkins (1969), but has relatively more impressed sutures with relatively wider and more tumid radials. These differences are all of slight degree.

| DISCUSSION
Generally, Carboniferous crinoids in Chinese tectonic blocks are found in a few fossil-rich beds in limited localities. Apart from a few records of deposits with high crinoid diversities in some Chinese blocks listed in the following, Carboniferous crinoids in the South China Block are rarely reported. Even though crinoid stems often occur with high abundance in shelly bank facies locally, crowns with diagnostic characteristics are rarely found; there is only one crown-preserved genus known. In order to provide an overview of crinoid taxa in China, we have compiled regional lists (Table 1), showing 34 genera and 62 species of Carboniferous crinoid taxa, plotted on a palaeogeographic map with the main tectonic regions (Figure 4).
This fauna was the highest abundance and diversity, and more closely related to the coeval European faunas than those from North American. The Junggar crinoid fauna has a low-diversity in Camerates and generally poor-preserved in fragmentary status, showing greatest biological affinity at the family level with Moscovian crinoid faunas of Japan and North America (Lane et al., 1996;Webster, Waters, & Chen, 2009;Webster, Waters, Liao, & Maples, 2009a;Webster, Waters, Liao, & Maples, 2009b). The North China crinoid fauna dominated by Cladida is well-preserved with low diversity and abundance, and implies biological affinities with those recorded in North America (Sheffield, 2015;Tien, 1926;Webster, 2003

ACKNOWLEDGEMENTS
Thanks to Professor Liao Zuoting for his helpful field work and discussion on the stratigraphy and identification on the brachiopods. We thank anonymous reviewers and editors for their critical comments and constructive suggestions that largely improved the manuscript.

CONFLICT OF INTEREST
We declare that all authors have no conflict of interest. We have data available.

PEER REVIEW
The peer review history for this article is available at https://publons. com/publon/10.1002/gj.4311.

DATA AVAILABILITY STATEMENT
The data that support the findings of this study are openly available in Zenodo at https://doi.org/10.5281/zenodo.5525903, reference number 10.5281/zenodo.5525903.