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The cranial anatomy of the captorhinid reptile Labidosaurikos meachami from the Lower Permian of Oklahoma

Study of Labidosaurikos meachami, from the Lower Permian Hennessey Formation (Sumner Group) of north-central Oklahoma, reveals the presence of over thirty new cranial characters not present in single-tooth-rowed captorhinids and Captorhinus aguti. However, it is uncertain if these new characters represent autapomorphies of L. meachami because the skulls of all other large, multiple-rowed captorhinids are poorly known; many of these characters may instead diagnose subclades of multiple-tooth-rowed taxa within Captorhinidae.

A new species of chimaeroid fish from the Upper Cretaceous of the Saratov region, Russia

Amylodon karamysh sp. nov. (Chondrichthyes, Holocephali, Chimaeridae) is described from the Early Campanian (Late Cretaceous) of the Saratov Region, Russia. It is based on a single mandibular plate with a relatively short outer margin and four small median tritors. The morphology of the mandibular plate of A. karamysh appears to have evolved from the condition in the chimaerid Ischyodus, which implies that the shearing-type dentitions of Amylodon and Rhinochimaera were probably of independent origin.

A new cheilostome bryozoan from the Cretaceous of India and Europe: a cyclostome homeomorph

The new ' malacostegan' cheilostome Chiplonkarina is an unusual genus previously misidentified as a cerioporine cyclostome because of extreme homeomorphy in both zooid-level and colony-level morphology. The type species, C. dimorphopora, is the dominant bryozoan in west-central India in the mid-Cretaceous Bagh Group, whose geology is briefly reviewed, and is recorded here for the first time in the Cenomanian of France. A second species, C. bretoni sp. nov., occurs in the Lower Cenomanian of France and Germany.

Interstipe webbing in the Silurian graptolite Cyrtograptus murchisoni

Although it has long been recognized that the Graptoloidea constituted a diverse group of planktic organisms, the precise hydrodynamics of the various colony morphotypes has been a source of debate. Recent discoveries of specimens of Cyrtograptus murchisoni with a complex suite of webs or vanes between the centrat coiled stipe and the cladial branches have shown that the hydrodynamic modifications of at least this taxor were considerably more complex than previously thought.

Ostracoda and palaeosalinity fluctuations in the Middle Jurassic Lealt Shale Formation, Inner Hebrides, Scotland

Molluscs, conchostracans, algae, palynomorphs and, in particular, ostracods are used to define fluctuating salinities in the Lealt Shale Formation, Great Estuarine Group (Upper Bajocian-Bathonian, Middle Jurassic). Salinities ranged from oligohaline (0-5-5%o) to mesohaline (5-18%o). Fluctuations were often rapid, occurring over only 10-20 mm of sediment. The Kildonnan Member of the Lealt Shale Formation is shown to have experienced a more unstable salinity history than the Lonfearn Member of the same formation.

A new eurypterid from the Late Ordovician Table Mountain Group, South Africa

An exceptionally preserved eurypterid, Onychopterella augusti sp. nov., is described from the Soom Shale Member of the Cedarberg Formation, Table Mountain Group, of Cape Province, South Africa, extending the temporal range of this genus into the late Ordovician and providing the first occurrence in Gondwana. O. augusti can be distinguished from related taxa by the shorter proportions of the postabdomen, lanceolate telson, the large anterior projection of podomere seven and the long terminal spine of the sixth prosomal appendage.

Oryctocephalid trilobites from the Cambrian of North America

Type and additional specimens of species of Oryctocephalus, Lancastria and Oryctocara are described. Oryctocephalidae have a rostral-hypostomal plate, and hence belong in the Order Corynexochida. Characteristic of the family is the development of lateral glabellar furrows as pits situated inside the axial furrow, and the absence of a border on the pygidium. Two subfamilies are used: Oryctocephalinae, having genal and pleural spines; Oryctocarinae lacking such spines.

The Sutton Stone: an Early Jurassic rocky shore deposit in South Wales

The unconformity between Jurassic and Carboniferous carbonates at Southerndown, near Ogmore-by-Sea, Mid-Glamorgan, represents an ancient rocky shoreline which has had a long history of study. Henry De la Beche discussed the ecological details of the unconformity surface, but subsequent debates focused more on the age and depositional setting of the basal Jurassic conglomerate known as the Sutton Stone. Our contribution returns to the theme of faunal development on the unconformity surface.
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