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Few bryozoan faunas have been reported globally from the time of the late-Ordovician mass extinction (LOME). A depauperate bryozoan fauna from the Kuanyinchiao Bed of North Guizhou Province, South China are described here as the first record following the first phase of the LOME. This bryozoan fauna includes five species belonging to five genera: Homotrypa ramulosa Bassler, 1903, Trematopora sp., Radiotrypa gothica Brood, 1978, Nematopora lineata (Billings, 1866), and Phylloporina sp. In generic composition and colony morphology, the bryofauna resembles contemporary examples from Sweden (Dalmanitina beds = Hirnantian), probably because of the similarities in their palaeoenvironment, including bathymetry, and depositional latitudes. [ABSTRACT FROM AUTHOR]

Although phosphatized bryozoans have been described recently from the early Cambrian, the first unequivocal bryozoan fossils with hard skeletons are known from the Ordovician. Recent discoveries of bryozoans in the early Ordovician (Tremadocian) of South China have greatly expanded our understanding of the diversification of these colonial lophophorates. In particular, the Fenhsiang Formation of Late Tremadocian age (Migneintian) in Hubei Province is proving to be particularly rich in bryozoans. Here we record 24 species, including several yet to be formally described, belonging to 18 genera and four palaeostomate suborders (Esthonioporata, Cystoporata, Trepostomata, and Cryptostomata). Bryozoan diversity in the Fenhsiang Formation matches levels more typical of younger faunas of Middle Ordovician age. The presence of diverse and morphologically disparate taxa close to the base of the Ordovician suggests rapid diversification following the first appearance of bryozoans with calcified skeletons, and/or the existence of as yet unknown biomineralized bryozoans in the Cambrian. [ABSTRACT FROM AUTHOR]

A new cryptostome bryozoan, Prophyllodictya simplex sp. nov., is described from the Nantzinkuan Formation ( Lower Ordovician, lower Tremadoc) of Liujiachang, central China. This antedates the previously oldest known bryozoan by several million years. Colony morphology and the phylogenetic position of Prophyllodictya within Cryptostomata are explored. Phylogenetic analysis suggests that Cryptostomata (except Prophyllodictya) can be divided into two major groups, and that Prophyllodictya occupies a basal position in the cryptostome tree, which accords with its simple morphology and antiquity. A close relationship is evident between bryozoans from the South China palaeoplate and those from Baltica. [ABSTRACT FROM AUTHOR]