Callianassid fossils, preserved within their burrows, collected from Mount Discovery, East Antarctica, provide the first such occurrence in Antarctica as well as evidence for deposition in a shallow marine environment distal to a deltaic system. The age of the specimens, based upon associated dinoflagellate cysts, is late early to middle Eocene.

The Namurian Tsingyuan Formation from Ningxia, China, is divided into three members. The remarkably well-preserved gastropods from the Tsingyuan Formation belong to three assemblages: the Angyomphalus longicostatus—Glabrocingulum tongxinensis assemblage from the Lower Member; an assemblage of some siliceous Bellerophon sp., and Naticopsis sp. from the Middle Member; and the Euphemites hindi—Turbonitella semisulcatus assemblage from the Upper Member. Based on the associated ammonoids and conodonts, these assemblages are considered equivalent to the Eumorphoceras, Homoceras2-Reticuloceras1 and Reticuloceras2 zones of West Europe respectively.

The Campanian-Maastrichtian-aged Grande Carriere quarry near Tercis, southwest France, contains a diverse and abundant assemblage of both micro-and macrofossils from a thick sequence of well-exposed limestones. Its fauna is also a mixture of both Boreal and Tethyan Province species. Because of these two traits, the quarry provides an excellent source of information about integrated biostratigraphic events among diverse taxa, as well as providing a reference section for correlation between the two biogeographic provinces. The quarry has recently been proposed as a candidate for the Campanian/Maastrichtian boundary stratotype section, while one ammonite found there, Pachydiscus neubergicus, has been proposed as the index fossil marking the base of the Maastrichtian Stage. We have made collections of Upper Cretaceous ammonites and planktonic foraminifera from limestones exposed in, and near this site, which yield new information about the relative stratigraphic ranges of Upper Campanian and Lower Maastrichtian ammonites and foraminifera.

Extensive collections of Pennsylvanian marine gastropods from 20 marine units in the Appalachian Basin contain 227 recognizable taxa. Twenty-two new species and subspecies are recognized including Bellerophon (Bellerophon) laticallis, B. (B.) graphicus varicallis, B. (Pharkidonotus) breyeri, Knightites (Cymatospira) montfortianus discordis, K. (Retispira) fascireticulatus, Colpites lirata, Abylea formosa, A. paradoxus, A insolitus, Spiroscala decorata, Euconospira equisita, Neilsonia invisitata, Worthenia parvula, Gosseletina nodosa, Glyptotomaria (Dictyotomaria) concinna, G. (D.) facta, G. (D.) decora, Phymatopleura preclara, Callispira grossa, Ceraunocochlis? subulata, Streptacis? ingens, and S.? complanata.

Correlation of marine stratigraphic units within the collection area are discussed. Zonation on the basis of pseudozygopleurid taxa, following that of Anderson et al. (1989), is presented as well as mention of characteristic taxa of the various series.

The microstructure of the non-window portions of the shell of Corculum cardissa resembles other Fraginae, with predominantly fibrous prismatic outer, branching crossed lamellar middle, and complex crossed lamellar inner layers. Both the anterior and posterior windows in its shell reflect reduced pigmentation and incursion of the outer shell layer, but the posterior windows involve deeper incursion plus reduction of the outer and middle sublayers of the outer shell layer and microstructural modification of the middle shell layer to enhance light transmission. The planoconvex shape of the posterior windows has more likely evolved to direct and focus light toward the deeper, zooxanthellae-rich gills and anterior mantle, than to merely disperse light.

Silicified material from the Early Caradoc part of the Las Aguaditas Formation in San Juan Province, Argentina, includes a nearly complete growth series for a new species of the tropidocoryphid Stenoblepharum Owens, 1973. Cladistic analysis of Stenoblepharum species indicates that S. astinii new species is most closely allied to the Early Caradoc S. strasburgense (Cooper, 1953) from Virginia. Chinese species of Stenoblepharum are sister group to a Baltic/Laurentian clade. A single adult-like protaspid stage occurs in the life cycle of S. astinii, closely resembling the protaspis of Decoroproetus. It is preceded by a non-adult-like first protaspid instar that appears to be characteristic of Proetoidea in general but contrasts markedly with the early larval stages of other taxa in Proetida.

Liromissus, a new genus of chionine bivalve from the Neogene of Venezuela, serves as an example of the link between geographic range, endemism and extinction susceptibility. Unlike other Neogene tropical American chionine genera, Liromissus was not widespread in the tropical Western Atlantic and Eastern Pacific, but was instead restricted to the Atlantic Gatunian region. Late Neogene extinctions in tropical America affected taxa with restricted geographic ranges, and regions with higher degrees of endemism more severely. Accordingly, Liromissus is the only tropical chionine genus to suffer extinction during the Neogene.

The type species of Liromissus, L. quirosensis, was originally described as a member of the genus Lirophora. Morphological considerations preclude this assignment, but also demonstrate that Liromissus possesses all the characters diagnostic of the Chioninae.

The new genus Herminespina comprises extinct South American species of “Thais”-like ocenebrine gastropods with prominent colabral folds and a labral spine. Geographic range extensions into Peru are reported for the late Pliocene H. mirabilis and the late Miocene to Pliocene H. philippii, both previously known only from Chile. A new early Pliocene species, H. saskiae, is described from the Sacaco Basin of southern Peru and compared with an early Miocene muricid from Peru and Chile, Acanthina katzi. Herminespina is one of several genera of Neogene muricids in western South America that bear labral spines.

Two new genera, Barrandecirrus (Porcelliinae) and Pernericirrus (Agnesiinae), from Upper Silurian marine sediments of the Prague Basin (Barrandian area, central Bohemia) are described. Both these genera belong to the family Porcelliidae and represent the oldest representatives of the superfamily Cirroidea (Vetigastropoda). The sinistrally coiled teleoconch of Barrandecirrus filiformis (Perner) suggests that the pseudobilaterally symmetrical teleoconch of the younger genera of Porcelliinae (Porcellia and Coloniacirrus) is a secondary shell character that originated during post-Silurian evolution of this group. In addition, the sinistral, low trochospiral teleoconch of early Agnesiinae [Pernericirrus sinistorsus (Perner) and Agnesia costata (Goldfuss)] as well as the asymmetrical position of the selenizone and the sinistral teleoconch in early Porcelliinae (Barrandecirrus filiformis) support the opinion that both Porcelliinae and Agnesiinae arose from the same stock. Data presented also suggest that the superfamily Cirroidea evolved during the Silurian or earlier, and it has developed parallel to and independently of other larger groups of the Vetigastropoda such as the Pleurotomarioidea and the Trochoidea.

New collections from the Marshalltown Formation and basal Mount Laurel Sand along the Chesapeake and Delaware Canal in Delaware clarify the ammonite dating of the interval. The Marshalltown Formation yields Pachydiscus (Pachydiscus) sp., Menuites portlocki (Sharpe, 1855) complexus (Hall and Meek, 1856), a subspecies restricted to the Baculites gregoryensis and Baculites scotti zones in the Western Interior of the United States, and Didymoceras binodosum (Kennedy and Cobban, 1993a) known only from the B. scotti zone of the Western Interior and correlatives in Arkansas and Texas. The basal part of the Mount Laurel Sand contains a complex assemblage preserved as phosphatic molds: Nostoceras (Nostoceras) monotuberculatum Kennedy and Cobban, 1993a, Nostoceras (N.) sp., Didymoceras platycostatum (Kennedy and Cobban, 1993b), D. stevensoni (Whitfield, 1877) (previously thought to be from the Marshalltown) and Exiteloceras jenneyi (Whitfield, 1877). The last two are index species of their eponymous zones in the Western Interior. This sequence is compatible with ammonites from the Wenonah Formation, which lies between the Marshalltown and Mount Laurel to the north and contains ammonites indicative of the Baculites scotti zone, and the fauna from higher in the Mount Laurel Sand, which includes elements of the Didymoceras cheyennense and Baculites compressus zones of the Western Interior sequence.

The Cretaceous and early Cenozoic species of the shallow-marine, warm-water bivalve Plicatula from California (United States) and Baja California (Mexico) are reviewed, and three new species are named. All of these species are representatives of Plicatula and not of the closely related taxon Harpax, which is associated with high-latitude and cool-water regions. The earliestknown Cretaceous species of Plicatula from the study area is P. variata Gabb, 1864, from Lower Cretaceous (Hauterivian Stage) strata in northern California, and our studies show it to be conspecific with Plicatula onoensis Anderson, 1958.

Plicatula allisoni new species is from Lower Cretaceous (Albian Stage) strata in Baja California, Mexico. Plicatula modjeskaensis new species is from Upper Cretaceous (Turonian Stage) strata in the Santa Ana Mountains, southern California. A possible new species from the same strata is also mentioned. A poorly preserved specimen of Plicatula? sp. is known from Upper Cretaceous (upper Campanian to lower Maastrichtian) strata in northern California.

The only Paleocene species of Plicatula from the study area is P. ostreiformis Stanton, 1896, from lower Paleocene strata of Lake County, northern California, and our studies show it to be conspecific with Ostrea buwaldana Dickerson, 1914. The only previously described Eocene species of Plicatula from the study area is P. juncalensis Squires, 1987, from lower middle Eocene (“Capay Stage”) strata of Los Angeles County, southern California. Plicatula surensis new species is from middle lower Eocene (“Capay Stage”) strata in Baja California Sur, Mexico. In addition, there is a Plicatula? sp. from Eocene strata of Baja California Sur, Mexico.

Although Plicatula is of uncommon occurrence north of Baja California, its thermophilic trait makes it useful in recognizing periods of warm climate.

A structured evolutionary pattern emerges from cladistic and stratocladistic analyses of the Calceocrinidae (Echinodermata). These Paleozoic disparid crinoids were dominated by three long-ranging genera, and other genera were derived during endemic radiations in North America and in Europe. Calceocrinid evolution was highly mosaic, including the repetition of morphological transitions, numerous character reversals, and evolutionary independence of characters.

As a family, the calceocrinids make up a highly derived, unique family because the crown is bilaterally symmetrical, is reflexed onto the stem by a hinge between the radial and basal circlets, and was normally situated just above the substratum. The analysis included 23 genera with 17 characters; three were coded as ordered based on previously observed evolutionary trends. Standard cladistic analysis yielded a total of 17,000 equally parsimonious trees. The addition of stratigraphic data through the use of stratocladistic methodology reduced this number to 16 equally parsimonious trees.

Brachysphingus is a low-spired bucciniform neogastropod known only from the fossil record of California and northern Baja California. The earliest species, Brachysphingus gibbosus Nelson, 1925, ranges in age from latest Cretaceous or possibly earliest Paleocene to the late Paleocene. During the early Paleocene, the smoothish B. gibbosus evolved into the axially ribbed B. sinuatus Gabb, 1869, which is the senior primary synonym of B. gabbi Stewart, 1927. During the late Paleocene, B. sinuatus evolved into B. mammilatus Clark and Woodford, 1927, which is the youngest species of Brachysphingus and which lasted into the early Eocene.

All three species of Brachysphingus were shallow-marine dwellers subject to transport into deeper waters via turbidity currents.

The bivalve molluscs Colpomya? sp. and Goniophorina (Cosmogoniophorina)? tenuicostata Harrington are recorded for the first time in the Arenigian Suri Formation (Famatina Range, western Argentina), and the new taxa Suria ovalis new genus and new species, and Redonia riojana new species are proposed. Additionally, the rostroconchid Ribeiria spinosa Babin and Branisa is also described. Some taxa shared with the Acoite Formation (Cordillera Oriental, Northwestern Argentina) and the Sella Formation (Cordillera Oriental, Bolivia) suggest that the Suri Formation was geographically related to these basins, and consequently, it could likewise be considered as a peri-Gondwanan area.

Larvae of three proetide trilobites are described from the Garden City Formation: Proetide A, Goniophrys prima, and Licnocephala cavigladius. The larvae of Proetide A share a spindle-shaped axis and natant hypostomal condition with other proetide larvae as synapomorphies. The forward-tapering glabella and slender posterior fixigenal area of post-larval cranidia of Proetide A indicate a close affinity to the earliest proetide family (Hystricuridae). The primitive nature of the larvae of Proetide A is further supported by the possession of plesiomorphic features, including four glabellar lobes and bilobed axial lobes (L1/L2/L3). Larval features of Goniophrys prima (a telephinid) such as an elliptical outline and smooth exoskeleton are not consistent with the hypothesis that the genus is the ancestor to younger telephinids. The larvae of Licnocephala cavigladius are typical of the Bathyuridae in having a smooth, ovoid shield and less distinct axial furrows.

A new species of carcineretid crab, Carcineretesplanetarius, is described from the Upper Cretaceous (lower Maastrichtian) Barton Creek Dolomite at Albion Island, Belize. The age is based on the stratigraphic range of associated nerineid gastropods and correlation with nannoplankton, benthic foraminifera, and the other known congeneric species of crab found in Jamaica. Confirmation of this age aids in constraining the timing of ejecta deposits of the Chicxulub impact found at the top of Barton Creek Dolomite exposed on Albion Island. Paleoenvironmental and paleoecological analyses suggest that these crabs were swimmers in lagoonal settings, capable of burrowing a few centimeters into the mud for protection.

Agnostoid trilobites from the Carlos Rusconi collections in the Museum of Natural Sciences of Mendoza, Argentina, are revised. The agnostoids were collected in the southern Precordillera of Mendoza Province, western Argentina. Revised taxa include Agnostus microcephalus (Rusconi), Lotagnostus (Lotagnostus) peladensis? (Rusconi), Lotagnostus (Lotagnostus) lasherensis (Rusconi), Homagnostus pehuenchensis Rusconi, Kormagnostus seclusus (Walcott), Kormagnostus? beltensis (Lochman in Lochman and Duncan), Hypagnostus parvifrons (Linnarsson), Ptychagnostus cuyanus (Rusconi), Ptychagnostus aculeatus (Angelin), Lejopyge laevigata (Dalman), Tomagnostella exsculpta (Angelin), Diplagnostus planicauda (Angelin), Oedorhachis typicalis Resser, Clavagnostus calensis Rusconi and Clavagnostus repandus (Westergård in Holm and Westergård). Some taxa of uncertain affinities are recognized and new specimens assignated to Lotagnostus and Pseudagnostinae are illustrated. Hypagnostus parvifrons, L. laevigata and C. repandus are reported for the first time in South America. Global correlation with previously described agnostoid faunas indicates that the outcrops range from middle Middle Cambrian to latest Late Cambrian in age.

Three homocrinid crinoids from the Upper Ordovician Maquoketa Formation of northern Iowa and southern Minnesota are described: Ectenocrinus simplex (Hall), Drymocrinus strimplei new species, and Sygcaulocrinus typus Ulrich. Ectenocrinus simplex is relatively abundant, geographically widespread in the Appalachians and midcontinent of North America, and long-ranging in time (Middle Ordovician Shermanian to Upper Ordovician Maysvillian). The aboral cup of ectenocrinids underwent transpositional allometry during its evolution so that juvenile cups from the Upper Ordovician Maquoketa Formation resemble the adult cups of ancestral individuals from the Middle Ordovician. Sygcaulocrinus typus exhibits a unique expanded proximal stem consisting of three-to-five large columnals throughout its post-larval development. These columnals are rigidly joined to the aboral cup. Consequently, the proximal generative zone for new columnals is displaced below the proximal part of the stem. In addition, the columnals in the proximal stem of S. typus mainly grow with stong positive allometry with respect to the aboral cup. Essentially, the growth vectors of the proximal columnals converge on those of the aboral cup plates.

Trilobites assigned to 29 genera and 39 species are reported from the Deadwood Formation in the Black Hills of South Dakota. Two new species, Prosaukia lochmani and Arcifimbria pahasapaensis, are described. Brachiopods are reported from the Taenicephalus Zone.

A biostratigraphic zonation is established for the upper part of the Deadwood Formation. The Taenicephalus Zone in the lower part of the study interval is succeeded upsection by the Ellipsocephaloides Zone, both of which are assigned to the Franconian Stage. These two zones are overlain in turn by the Illaenurus and Saukia Zones of the Trempealeauan Stage. These zones are used to correlate this part of the Deadwood with coeval strata in Montana and Wyoming, central Texas, Oklahoma, and Alberta, Canada. The lowstand of sea level that occurred in the Great Basin at the time of the deposition of the Saukiella junia Subzone of the Saukia Zone probably extended eastward into the Black Hills, resulting in the absence of this fauna in the Black Hills.

Living ectocochliate cephalopods have long been thought to be restricted to a single genus, Nautilus Linnaeus, 1758, comprising five or six extant species. The shells of two species, N. scrobiculatus Lightfoot, 1786, and N. perforatus Conrad, 1847, are quite distinct, but no soft-parts were known until 1984, when N. scrobiculatus was seen alive for the first time. Dissections show that significant anatomical differences exist between N. scrobiculatus and other Nautilus species, including differences in gill morphology and details of the male reproductive system. These differences, along with phylogenetic analysis of extant and selected fossil nautiloid species, indicate that N. scrobiculatus, and N. perforatus should be distinguished from Nautilus as a newly defined genus, Allonautilus. This analysis contradicts previous phylogenies proposed for the Nautilida, which placed Nautilus as the last-evolved member of the order. We surmise that Allonautilus is a descendent of Nautilus, that the latter is paraphyletic, and first evolved in the Mesozoic, rather than in the late Cenozoic, as has been previously suggested.