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The Middle Permian Chihsia and Maokou formations in Laibin, central Guangxi, South China contain 19 rugose coral species; of these taxa, Lophocarinophyllum sandoi, Asserculinia solida, and Innixiphyllum wuae are new. Innixiphyllum represents a new genus characterized by contratingent minor septa. Ten species are reviewed and described in detail, and the diagnoses of three of these species, Allotropiophyllum heteroseptatum (Grabau, 1928), Lophocarinophyllum taihuense (Yan and Chen, 1982), and Ipciphyllum regulare (Wu, 1963), are newly emended. The morphological variation and ontogenetic changes of the solitary, nondissepimented species are particularly emphasized. Six additional taxa are described and illustrated but are left in open nomenclature.
The corals from Laibin are typically Tethyan. Four biostratigraphic assemblages are recognized: an assemblage of massive corals in the upper Chihsia Formation represented by Polythecalis longliensis; an assemblage of small solitary and nondissepimented corals in the lower Maokou Formation, dominated by species of Allotropiophyllum, Innixiphyllum and Lophocarinophyllum; an assemblage of mixed massive colonial and small solitary corals in the middle Maokou Formation, characterized by Ipciphyllum regulare; and an assemblage of solitary nondissepimented corals in the uppermost Maokou Formation, characterized by Ufimia elongata. These assemblages correspond well to those from other areas of South China. In Laibin, only two rugose taxa, Amplexocarinia sp. and Paracaninia minor, occur in the basal part of the Wuchiaping Formation of Lopingian age.
The cladid crinoid order Poteriocrinida Jaekel, 1918 is a polyphyletic group that includes a variety of independent lineages united solely by the presence of ramulate or pinnulate arms. One of these lineages is the Rutkowskicrinidae new family herein assigned to the order Dendrocrinida, Bather 1899. Genera assigned to this new family include Rutkowskicrinus new genus, Decorocrinus new genus, Iteacrinus, Nassoviocrinus, Quantoxocrinus, Sacrinus, Sostronocrinus, ?Propoteriocrinus, and ?Schmidtocrinus. Members of this family are characterized by low conical cups with ridged thecal plates, U-shaped peneplenary radial facets bearing faint transverse ridges, a proximal median ridge on the posterior side of a long, narrow, predominantly straight anal sac, and pentagonal columns with one to two cirri per nodal. Arms in this family are highly variable, ranging from isotomous to heterotomous and pinnulate. The arms in the type specimen of Rutkowskicrinus patriciae n. sp. preserve all these various arm stages. The oldest presently known rutkowskicrinids occur in the Late Silurian (Ludlovian) of Australia and the Early Devonian (Pragian) of western Europe. The family diversified during the Middle Devonian (Givetian) in northeastern North America, and declined in numbers and diversity throughout the Late Devonian before going extinct in the Early Mississippian (Tournaisian).
The Glossocrinidae Goldring, 1923, containing Glossocrinus, Charientocrinus, Catactocrinus, and Liparocrinus, is also reviewed. This family, distinguished by a strongly recumbent anal sac in the B-E plane and a prominent median ridge extending the entire length of the anal sac, was derived from the Rutkowskicrinidae during the Middle Devonian (Givetian) and diversified in the Late Devonian before going extinct at the Frasnian-Famennian boundary.
The previously described rutkowskicrinid and glossocrinid genera listed above were assigned by Moore et al. (1978) to the dendrocrinid family Mastigocrinidae and poteriocrinid families Rhenocrinidae, Poteriocrinitidae, and Scytalocrinidae. Studied taxa include Rutkowskicrinus patriciae new genus and species, Rutkowskicrinus collieri new genus and species, Nassoviocrinus costatus (Goldring, 1954) new combination, Nassoviocrinus schultzei (Haarmann, 1921) new combination, Nassoviocrinus? duluki (Kesling, 1969) new combination, Nassoviocrinus? ornatus (Goldring, 1954) new combination, Nassoviocrinus? chilmanae new species, Decorocrinus arkonensis (Goldring, 1950) new combination, Decorocrinus cooperi (Goldring, 1926) new combination, Quantoxocrinus clarkei (Williams, 1882) new combination, Glossocrinus halli (Goldring, 1923) new combination, and Charientocrinus bellitubatus (Kesling, 1973) new combination.
Comprehensive analysis of the Cretaceous and Tertiary decapod crustaceans of the North Pacific Rim, focused primarily on the Brachyura, has resulted in additions to our understanding of the evolution and distribution of these animals, both in that region and globally. Hypotheses about changes in climatological and paleoceanographic conditions have not been extensively tested using decapod crustaceans, although they have been well-documented globally and for the North Pacific Ocean by sedimentological and other faunal evidence. Evidence from the occurrences of decapod crustaceans supports hypotheses obtained through these other means. Because the decapod fauna was studied independent of other faunas, it provides a means by which to compare and test patterns derived from molluscan and other faunal data. The brachyuran decapods show distinctive paleobiogeographic patterns during the Cretaceous and Tertiary, and these patterns are consistent with those documented globally in the molluscan faunas and paleoceanographic modeling. Additionally, the changes in the decapod fauna reflect patterns unique to the North Pacific Ocean. The decapod fauna is primarily comprised of a North Pacific component, a North Polar component, a component of Tethyan derivation, an amphitropical component, and a component derived from the high Southern latitudes. The Cretaceous and Tertiary decapod faunas of the North Pacific Ocean were initially dominated by taxa of North Pacific origin. Decapod diversity was highest in the Pacific Northwest of North America during the Eocene, and diversity has declined steadily since that time. Diversity in Japan was relatively low among the Decapoda until the Miocene, when diversity increased markedly due to the tropical influence of the Tethys and Indo-Pacific region. Diversity has remained high in Japan into the present time. The Cretaceous, Eocene, and Miocene were times of evolutionary bursts within the Brachyura and were separated by periods of evolutionary stasis.
New shumardiid trilobites from Arenig to Early Caradoc deposits of the Argentine Precordillera include species of a revised Kweichowilla (K. salasae, K. sterrenae, and K. piojensis) and the new genus Changchowilla (C. sanjuanina and C. gracielae, and C.? carrerai). Conophrys fabiani new species occurs in the Early Tremadoc of the western Puna region, northwestern Argentina. Leoforteyia new genus is based on L. hintzei new species from the Ibexian of Utah. Published taxa recognized as new species are Conophrys rushtoni, Conophrys wrighti, Leoforteyia ludvigseni and Shumardia whittingtoni. Phylogenetic analysis suggests the differentiation of Shumardia Billings, 1862; KweichowillaChang, 1964; Changchowilla new genus; and Leoforteyia new genus as separate taxa and indicates that Conophrys Callaway, 1877, is a grade group. Silicified material provides a nearly complete growth series for Kweichowilla salasae, including the first protaspides known with confidence for the Shumardiidae. Additionally, ontogenetic material for K. sterrenae, C. sanjuanina, C. riojana (Benedetto and Cañas) and C.? carrerai is described.
Leoforteyia is restricted to the Ibexian-Whiterockian of western Laurentia; species of Shumardia are widespread in the Arenig to Early Ashgill of western Europe, Australia, Laurentia, China and Russia. Changchowilla is recorded in the mid-Late Arenig-Llanvirn of the Precordillera and in the Llanvirn-middle Caradoc of China. Argentine species of Kweichowilla are closely allied to Australian species, suggesting biogeographic affinities of the Precordillera to the eastern margin of Gondwana by the Llanvirn and Caradoc.
Functional morphology, occurrence in fine grained sediments, and association mainly with atheloptic and pelagic trilobites suggest that shumardiids were deposit-feeders that inhabited low light levels in low energy settings, with a limited ability to burrow in soft sediments.
The oldest Jurassic marine pleurodire is reported from the Jagua Formation in western Cuba. These remains are from levels of middle and late Oxfordian age. This turtle represents a new genus and species, Caribemys oxfordiensis. A phylogenetic hypothesis is proposed, whereby Caribemys is considered to be the sister group of NotoemysCattoi and Freiberg, 1961, plus the Eupleurodira Gaffney and Meylan, 1988. The occurrence of Caribemys oxfordiensis n. gen. and sp. in the Jagua Formation along with plesiosauroids, pliosauroids, ophthalmosaurian ichthyosaurs, and metriorhynchid crocodiles, strongly suggests that during the Oxfordian a marine seaway was present in the Caribbean, connecting the western Tethys with the Pacific Ocean.
A freshwater interbed of the Yemen Volcanic Group in central western Yemen yielded impressions of numerous, articulated, mostly complete frog skeletons. Recent dating of the volcanics and the stratigraphic position of the fossil bearing bed in the sequence support a Late Oligocene age for the frogs. These frogs are described as a new species of Xenopus, a genus that is today mostly confined to subsaharan Africa, and they provide evidence of the former, wider distribution of this genus on the Afro-Arabian Plate. The new species, X. arabiensis, differs from other Xenopus in its long maxilla and maxillary tooth row. It resembles X. muelleri in its dentate, azygous vomer and prominent, cone-shaped, distally-pointed prehallux, but differs from X. muelleri in having an atlantal intercotylar notch and longer distal prehallux bone. Climatic changes during the Neogene probably led to the extinction of Xenopus on the Arabian Peninsula; however, the timing of this event is not certain.