X-ray CT scans at two different energies of three articulated specimens of Spathelopsis oakvalensis n. sp., a bivalve from the Bluefield Formation of the Mauch Chunk Group (Mississippian, Chesterian) from southeastern West Virginia, permitted observation and description of poorly known internal features of the shell, resulting in a reversal of the shell orientation alleged by past authors and concomitant reassignment of this problematic genus to the palaeotaxodont family Nuculanidae Adams and Adams. Distinctive posterior and anterior gapes in Spathelopsis suggest separation of inhalant and exhalant water streams, a characteristic associated with derived but not primitive palaeotaxodonts.

Three new archisargid species referred to one new genus, Flagellisargus sinicus, F. venustus and F. robustus, are described based on three impressions from the Callovian–Oxfordian of the “Daohugou Formation” in Daohugou, Chifeng, Inner Mongolia, China. The presence of an elongated flagellum and large male genitalia places these new findings with the distinct but rare archisargid flies. The systematic position of Origoasilus pingquanensis Zhang et al., 2011 is reassessed, placing it with Archisargidae within Archisargoidea rather than Asiloidea. The Origoasilidae is a junior synonym for Archisargidae.

Rare to abundant specimens of Moorites Coryell and Billings, 1932, and Discoidella Croneis and Gale, 1938, have been recovered from 13 Pennsylvanian stratigraphic units in the Appalachian basin. Eight species of Moorites, including the new species M. sturgeoni, M. ornatus, M. percultus, and M. erugatus, are recognized. Discoidella is represented by D. lingulata Cooper, 1946. Moorites hewetti Coryell and Billings, 1932, is recognized as the type species of Moorites. An ontogenetic series of M. percultus illustrates changes in shape and ornamentation. Increase in complexity of ornamentation from Lower to Upper Pennsylvanian provides a basis for specific identification.

The genus Bimuria Ulrich and Cooper, 1942, is a biogeographically important member of middle and late Ordovician brachiopod faunas of the Callahan–Gazelle area in the eastern Klamath Mountains of northern California. In middle Ordovician deposits the genus is widespread and ranges from Nevada in the west to southwestern Siberia in the east; however, in late Ordovician beds it was previously known only in Sweden and Northern Ireland. In addition to the northern California occurrence reported here, new late Ordovician occurrences are also noted in east-central Alaska–Yukon Territory and Northwest Territories. Three species of Bimuria are described, including the new species, B. californiensis.

A preliminary survey of species described in the literature suggests that the ratio of the length of the dorsal adductor field to the length of the elongate area in the brachial valve decreases from middle to late Ordovician species, and thus may be of biostratigraphic value.

A specimen of a remarkable new catfish genus and species was collected in middle/late Miocene marine beds of the Puerto Madryn Formation at the base of the marine cliff of the sea lion colony area near Puerto Pirámide, southern coast of Península Valdés, northeastern Patagonia, Argentina. Siluriforms (catfishes) constitute a most important monophyletic ostariophysan group of mainly freshwater fishes that occurs in almost all continents but it is especially diverse in South America. Catfishes are presently distributed in tropical to temperate areas and a small number of species are marine or amphibiotic. The new catfish shows many primitive features for catfishes in the maxilla, autopalatine, hyal elements, and Weberian apparatus. The genus is clearly distinguished by four autapomorphies: sand clock–shaped autopalatine, posterior limb of autopalatine widening strongly, post-articular arm of autopalatine longer, and a metapterygoid longer than broad. One tree was obtained both under equal and implied weighting with the following topology: a basal polytomy in the Siluriformes formed by Diplomystidae, Bachmanniidae, Kooiichthys and the Siluroidei. The new species appears to have been a marine or amphibiotic taxon: it was collected in beds considered to represent the Maximum Flooding Horizon of the transgression that deposited the Puerto Madryn Formation. The coast at this moment was at approximately 90 km to the west. According to faunistic evidence, the sea was warm temperate.

Lytohoplites Spath, 1925 is a late Tithonian–?early Berriasian ammonoid genus with a southern perigondwanean distribution. Two Lytohoplites species, L. burckhardti (Mayer-Eymar in Burckhardt, 1900) (type species) and L. vetustoides (Burckhardt, 1903), were originally described from carbonate successions of the Vaca Muerta Formation, Neuquén Basin, Argentina. Nevertheless, the holotype of L. burckhardti consisted of a single incomplete specimen that is currently missing. This situation compelled the search for new Lytohoplites specimens in Argentina and the selection of a neotype for L. burckardti. New Lytohoplites representatives were obtained through bed-by-bed collections performed at five localities in the Neuquén Basin. In addition to the taxonomic revision of the Lytohoplites species occurring in the basin, a paleobiological approach was preferred to conduct a paleontological analysis of L. burckhardti, including a description of its ontogeny, probable sexual dimorphism, and spectrum of intraspecific variability. Results of the qualitative and quantitative analyses supported the homogeneity of L. burckhardti as a taxonomic unit, thus implying that L. vetustoides should be considered its synonym. Lytohoplites in the Neuquén Basin is restricted to beds assigned to the Andean Substeueroceras koeneni Assemblage Zone (upper Tithonian–lower Berriasian), and not to the Andean Corongoceras alternans Assemblage Zone (upper Tithonian). Furthermore, the paleobiogeographic distribution of Lytohoplites around southern Gondwana and the herein reported occurrence of L. subcylindricus Collignon, 1962, otherwise only known from Madagascar, lend support to the existence of a functional trans-Gondawana seaway at least since the upper Tithonian.

The generic name Petrostroma proposed by Stearn (1991) for a Paleozoic stromatoporoid with type species Petrostroma simplex (Nestor, 1966) is preoccupied by a calcareous sponge described in 1892 by Döderlein.

Members of the subfamily Ursinae dispersed into North America from Africa and Asia during the Miocene, with the appearance of Ursavus (Schlosser, 1899), Indarctos (Pilgrim, 1913), and Agriotherium (Wagner, 1837) (Dalquest, 1986; Miller and Carranza-Castañeda, 1996; Hunt, 1998). However, none of these genera were thought to have survived past the Hemphillian Land Mammal Age in North America. It is thought that these genera were replaced, and possibly out-competed, by members of the extant genus Ursus (Linnaeus, 1758), or Plionarctos (Frick, 1926), as suggested by several sources (Bjork, 1970; Dalquest, 1986; Bell et al., 2004). It has also been suggested that the Ursavini (Agriotherium and Indarctos) may have given rise to the extant ursids and the Tremarctinae (Harrison, 1983; Miller and Carranza-Castañeda, 1996). Of the Ursavini, Agriotherium is consistently found in the Hemphillian Land Mammal Age, and so is used as an index fossil in that its absence is assumed to indicate that a site is Blancan rather than Hemphillian (Lundelius et al., 1987; Bell et al., 2004; Hunt, 2004).

An extensive faunule of silicified calcareous sponges has been recovered from the Upper Guadalupian Reef Trail Member of the Bell Canyon Formation, from the Patterson Hills, in the southwestern part of the Guadalupe Mountains National Park in western Texas. This is the youngest silicified faunule of Permian sponges known from that area, and possibly the youngest from North America. It includes the hypercalcified ceractinomorph “sphinctozoans” Amblysiphonella sp., Tristratocoelia rhythmica Senowbari-Daryan and Rigby, 1988, Colospongiella permiana n. gen. and sp., Exaulipora permica (Senowbari-Daryan, 1990), Parauvanella minima Senowbari-Daryan, 1990, and the “sphinctozoans” Girtyocoelia beedei (Girty, 1909), Sollasia ostiolata Steinmann, 1882, Sollasiella reticulata n. gen. and sp., Ramosothalamiella divaricata n. gen. and sp., and Spica texana n. sp. Also present are Guadalupia zitteliana Girty, 1909, Guadalupia minuta n. sp., Lemonea cylindrica (Girty, 1909), and Lemonea micra Rigby, Senowbari-Daryan, and Liu, 1998. Aspiculate calcareous sponges include the “inozoids” Preperonidella rigbyi (Senowbari-Daryan, 1991), ?Djemelia sp., Radiotrabeculopora virga n. sp., Daharella ramosa Rigby and Senowbari-Daryan, 1996, Daharella pattersonia n. sp., Daharella crassa n. sp., and Newellospongia perforata n. gen. and sp. The problematic Lercaritubus problematicus Flügel et al., 1990 is tentatively included with the “inozoids.”

The new siliceous protomonaxonid demosponge Monaxoradiata lamina n. gen. and sp., is a moderately common sponge from the member. The new siliceous lithistid demosponges Chiastocolumnia cylindrica n. gen. and sp., Dactylites obconica n. sp., and Dactylites magna n. sp., the large hexactinellid sponge Toomeyospongia gigantia Rigby and Bell, 2005, and the new lyssacinosid Flexuospiculata hexactina n. gen. and sp., along with isolated large hexactines, are associated with these silicified calcareous sponges from the Reef Trail Member. Toomeyospongia gigantia Rigby and Bell, 2005, described earlier, is the only large complete hexactinellid sponge that is part of the Reef Trail Member assemblage.

The problematical Pulsatospongia obconica n. gen. and sp., whose taxonomic position is uncertain, along with an encrusting possible inozoid sponge, and spicule-lined ?burrows are also described as part of the fossil assemblage.

Significant faunal similarity occurs between this assemblage and those from several areas within the Paleo-Tethys Sea, especially with those from the Djebel Tebaga area of Tunisia. This suggests significant faunal exchange between the two regions, possibly resulting from strong trans-Panthalassan equatorial currents and a significant anti-cyclonic gyre within the Paleo-Tethys basin.

New collections, as well as original type material, of Lower and Middle Ordovician sponges from the Mingan Island Archipelago are described and figured from the Mingan and Romaine Formations. Archaeoscyphia minganensis (Billings, 1859), Hudsonospongia minganensis Raymond and Okulitch, 1940, H. irregularis Raymond and Okulitch, 1940, H. duplicata Raymond and Okulitch, 1940, Zittelella varians (Billings, 1861a), and Eospongia roemeri Billings, 1861, are redescribed from original type specimens and new collections. The species Archaeoscyphia pulchra (Bassler, 1927), Rhopalocoelia clarkii Raymond and Okulitch, 1940, Psarodictyum magnificum Raymond and Okulitch, 1940, and Lissocoelia ramosa Bassler, 1927 are reported and described from the Mingan Islands for the first time. To these sponges are added the new species Anthaspidella amplia, Archaeoscyphia undulata, Hudsonospongia nodosa, and Zittelella grossa, which are described from type specimens from the Mingan Formation.

The assemblage from 12 localities from the Mingan Formation, and one from the Romaine Formation, represents one of the most diverse demosponge faunas from eastern North America. Sponges in most of the localities accumulated as transported debris or lag gravels, but locally, some grew in small reefoidal mounds and also accumulated as adjacent debris.

An Upper Triassic metaspondyle dasycladacean alga, Diplopora oregonensis n. sp., is described from the Hurwal Formation, southern Wallowa Mountains, northeastern Oregon. It occurs in the accreted Wallowa terrane, which is interpreted as far-travelled relative to the craton of North America. The fossil alga is found in limestone clasts within a limestone–chert–volcanic clast conglomerate of the Hurwal Formation. The new species is related to Diploplora borzai Bystricky, known from the Upper Triassic of the Carpathian Mountains and Sicily, but is distinguished by very small branches and a distinct segmentation of the thalli. Diplopora oregonensis is the first Triassic dasycladacean alga known from the United States, and perhaps from all of North America. The absence of calcareous green algae from rocks of cratonal North America, as well as from most Triassic displaced terranes of the eastern and western Pacific, is in stark contrast to counterparts in the former Tethys region of central Europe, where dasycladacean algae were abundant and contributed significantly to the sediment. This paucity of algae may be related to differences in environment, but more likely is linked to the paleogeographic situation and dispersal abilities of the algae. The similarity of the Oregon dasyclads to species in western Europe, coupled with the lack of dasyclad algae in any other part of North America, is evidence in support of a far-travelled nature for the Wallowa terrane.

The Early Permian (late Sakmarian to early Artinskian) adrianitid ammonoid Nevadoceras steelei new genus and species occurs in a fauna containing the ammonoids Properrinites Elias, Prothalassoceras Böse, Daraelites Gemmellaro, Almites Toumanskaya, Bamyaniceras Termier and Termier, Akmilleria Ruzhencev, Agathiceras Gemmellaro, Metalegoceras Schindewolf, Stenolobulites Mikesh, Glenister, and Furnish, Crimites Toumanskaya, Neocrimites Ruzhencev and the conodonts Sweetognathus whitei (Rhodes) and Mesogondolella bisselli (Clark and Behnken). This fauna occurs in a concretionary interval within micritic basinal facies of the Dry Mountain trough at Portuguese Springs, White Pine County, east-central Nevada.

Cyclocystoids are one of the rarest and most enigmatic of the extinct echinoderm groups. Despite recent systematic revision (Smith and Paul, 1982), their basic anatomy and functional morphology remain poorly understood. Smith and Paul (1982) recognized eight genera and 39 species ranging in age from Lower Ordovician to Late Devonian. Since then, one new genus and species, Monocycloides oelandicus, has been established by Berg-Madsen (1987), and the range of the genus Sievertsia has been extended to the Middle Devonian of the U.S.A (Fluegeman and Orr, 1990). In addition, undescribed cyclocystoid marginal ossicles have been found in the Lower Carboniferous of Ireland (G. D. Sevastopulo, personal communication). Here we record an additional new species from the Late Ordovician of Kentucky.

The remaining terrestrial gastropod fauna of the late Oligocene–early Miocene Cabbage Patch beds of western Montana is composed of nine new species, all from extant genera now occurring in the western United States: Vallonia berryi, [Succineidae] montana, Nesovitrea pulchra, Deroceras securis, D. mahiz, Punctum alveus, Polygyroidea montivaga, Oreohelix brandi, and Monadenia? n. sp. A, which is described from neanic material. All except the Monadenia? represent first occurrences of the respective genus in North America. The terrestrial fauna suggests that climatic and environmental conditions during the late Oligocene–early Miocene interval must have been very similar to those of the present. Two sizes of gastropod eggs, attributed to P. montivaga and V. berryi, were found at one locality. Monadenia? n. sp. A is of limited use, due to rarity, as an index fossil for the upper Cabbage Patch beds.

Early Permian massive corals define a narrow zone (the Thysanophyllum coral belt of Stevens, 1982) that surrounded the northern and western margins of Pangaea from the southern Ural Mountains through western North America to Bolivia (Stevens, 1982; Wilson, 1990). This belt appears to have been essentially continuous in the Wolfcampian, and although massive corals persisted along this belt into the Leonardian, they were restricted to many fewer localities.

A new fossil Ictiobus species is described, based on an abundant collection of well-preserved isolated bones found in lacustrine deposits of Pliocene (Blancan) age near Tula de Allende, state of Hidalgo, central Mexico. This fossil Ictiobus species shows the diagnostic character of the genus. In the palatine bone the ethmoid process is longer than the premaxillary process. Suspensorial pleural ribs with trapezoidal shape and a dentary bone with extremely short and wide gnathic ramus are the characters that support the creation of this new Ictiobus species. The fossil record of Ictiobus, the first known in Mexico, extends the paleogeographical distribution known of this genus, which had been previously restricted to the USA.

From the Aseelah Unit (Saal Formation), Batain Coast (eastern Oman), 48 bryozoan species were described. Eight species of them are new: cystoporids Cystodictya augusta n. sp. and Sulcoretepora orientalis n. sp., trepostomid Ulrichotrypella omanica n. sp., rhabdomesids Streblotrypa (Streblotrypa) binodata n. sp., Rhabdomeson coniforme n. sp., R. latum n. sp., Orthopora punctata n. sp., and phyloporine Rhombocladia quasiminor n. sp. A new combination is erected: Streblotrypa (Strebloscopora) katoi Sakagami, 2000 n. comb. Fifteen species are described in open nomenclature. the fauna shows mainly Lower to Middle Permian age, and paleobiogeographic connections to the Urals, southeast Asia and Australia.

A detailed morphological study of over 2,500 Middle Ordovician (Black Riveran) lophospirid archaeogastropods from the lower half of the Platteville Formation (Pecatonica Member and Mifflin Submember of the McGregor Member), principally as it is exposed in southern Wisconsin, has permitted the definition of five species of Lophospira. Lophospira perangulata (Hall), L. milleri (Hall), L. serrulata (Salter), L. helicteres (Salter), and L. delicata (n. sp.) are preserved throughout a three-meter interval of fine-grained, heavily bioturbated carbonates, now dolomitized. Deposition took place on a broad, shallow tropical shelf, which was characterized by low rates of deposition and low physical energy. The sampled interval represents about 500,000 years. The benthic marine invertebrate fauna is well preserved, diverse, and characteristic of an environment of normal marine salinity.

Of the five Lophospira species, only one, L. perangulata, has been positively identified in older strata (late Whiterockian, eastern North America). The other four species were endemic to the interior seas, and apparently at least two of these, L. serrulata and L. helicteres, did not survive into post-Platteville (post-Black Riveran) environments. Changes in the proportions of lophospirid species from the Pecatonica into the Mifflin strata probably reflect subtle changes in the distribution of carbonate shelf habitats but no major alteration in the kinds of habitats available for colonization.

Cretaceous clavagellid pelecypods are a poorly known group, and have previously received little study. Ascaulocardium armatum is conchologically the most complex burrowing pelecypod known. From the study of living clavagellids, it is possible to interpret the various tubes extending outward from the adventitious crypt of A. armatum as devices for hydraulic burrowing and deposit feeding. The conchologically complex A. armatum occurs near the beginning of the history of the Clavagellidae, and does not seem to have given rise to any younger species. Ascaulocardium armatum is known only from the Upper Cretaceous rocks (Santonian–Maastrichtian) of the east Gulf and Atlantic Coastal Plains of the United States of America, as is probably the genus Ascaulocardium. All known Cretaceous clavagellids are burrowing species having a free right valve, and this is the ancestral mode of life of the Clavagellidae. Clavagellids that have a boring habit are a more recent evolutionary development, as are burrowing species having both juvenile valves cemented to the crypt. Clavagellids probably evolved from Jurassic–Early Cretaceous pholadomyids. Almost all Cretaceous clavagellids occur outside the Tethyan Zoogeographic Realm; this distribution is in marked contrast to the modern distribution of the family. Living species mostly inhabit clear, shallow seas in subtropical to tropical shelf areas.

In contrast to the immense effort that has been put into the geological survey and stratigraphic study of the Neogene of Bocas del Toro region (Panama), little research has been done on the systematics of this region's rich gastropod assemblages. This is the first paper dealing primarily with the Bocas Neogene gastropod assemblages (Strombidae) since the pioneer work of Olsson (1922). Neogene strombid assemblages of the Dominican Republic have recently been reviewed and updated, and, therefore, the Strombidae are a suitable starting point for the revision of the gastropod assemblages from the Neogene of Bocas del Toro. Six species of Strombus are described, three of them new: S. acanthospira n. sp., S. pugiloides, S. gatunensis, S. elegantissimus n. sp., S. vermeiji n. sp. and S. cf. floridanus.