The diversity and distribution of teleosts in the Dinosaur Park Formation of Alberta, Canada, is evaluated on the basis of precaudal centra. In order to avoid the erection of redundant taxa, and to include all teleost precaudal centra in a single system, a parataxonomic system is erected. Fifteen distinct basal groups, termed morphoseries, are described. Growth-related changes and serial variation along the column are taken into account in defining these groups, so each morphoseries is interpreted as representing a distinct, low-level taxon of teleost. One of the morphoseries could be identified as hiodontid and two as acanthomorph on the basis of derived character-states. This is the first Cretaceous record of hiodontids in North America. In addition, elopomorphs, clupeomorphs, salmoniforms, and osteoglossoforms are recognized on the basis of general similarity with the precaudal centra in extant members of these groups. Two teleosts of intermediate level of evolution, but of uncertain relationships, are also present. Differences in the stratigraphic distributions of the morphoseries allow two distinct assemblages of teleosts to be recognized in the formation. One is present in fluvial-dominated localities of the Dinosaur Park Formation, the second in a complex of mud-filled channels in the Lethbridge Coal Zone. The paleoecological complexity present in the formation, and the high level of diversity of teleosts in these beds, emphasizes the importance of including disarticulated remains in studies of the diversity and distribution of teleosts in the Cretaceous.

Faunal data provide critical constraints upon tectonic models, particularly in such areas of extreme structural complexity as the region adjacent to the eastern syntaxis of the Himalaya. Trilobites reported to have been collected from the Yunling collage at Yinchangou, northwestern Yunnan, are here assigned to Kunmingaspis yunnanensis Chang, 1964, and the concept of the genus Kunmingaspis is reconsidered. Although there is debate about to the paleogeographic affinities of the Yunling collage, the apparent presence of this species supports previous arguments for faunal links between the Yangtze platform and the Himalayan margin during Early and Middle Cambrian time. A significant tectonic event of Late Cambrian/Early Ordovician age present in the western central Himalayan margin suggests that the Lhasa block collided with India at that time, but the northward extent of that block remains unclear. The recently discovered Late Cambrian trilobite fauna of Bhutan may hold the key to establishing faunal relationships between the Tethyan Himalaya, Sibumasu, and the Yangtze platform during this interval. No Cambrian sedimentary rocks are yet known from the Lhasa or Qiangtang blocks of Tibet and so there is no direct evidence for the existence of Cimmeria during the Cambrian Period.

The Callapoid family Necrocarcinidae Förster, 1968, was a successful group of crabs distributed worldwide and ranging in age from the Early Cretaceous to the Oligocene. Included taxa appear to have preferred littoral to sublittoral environments (e.g., Fraaye, 1994), have crawled closely appressed to the bottom and/or to have sheltered in muddy bottoms (Bishop and Williams, 1991), and probably were adapted to temperate to tropical climatic settings (Schweitzer and Feldmann, 2000). This lifestyle is similar to that of extant calappids. Before the present study only two calappids were known from the Maastrichtian type area. Both these species, Prehepatus werneri Fraaye and Collins, 1987, and Paranecrocarcinus quadriscissus (Noetling, 1881), have been described and discussed in detail by Collins et al. (1995).

The fossil record of siliceous sponges—Hexactinellida and demosponge “Lithistida”—hinges upon both body fossils plus isolated spicules mostly recovered from limestones by acid digestion. The earliest record of siliceous sponge spicules extends back to the late Neoproterozoic of Hubei, southern China (Steiner et al., 1993) and Mongolia (Brasier et al., 1997), and body fossils attributed to the hexactinellids have been described from the Ediacaran of South Australia (Gehling and Rigby, 1996); thus they are the oldest-known definite representatives of extant animal phyla. The Early Cambrian saw a remarkable diversification in spicule morphology, with the appearance of an essentially “modern” array of forms (Zhang and Pratt, 1994). While a diversity decline may have occurred with the late Early Cambrian extinction(s), the subsequent Paleozoic and Mesozoic fossil record of spicules shows a relatively consistent range of morphologies (e.g., Mostler, 1986; Bengtson et al., 1990; Webby and Trotter, 1993; Kozur et al., 1996; Zhang and Pratt, 2000). However, because spicule form is not restricted to individual taxa and many sponge species secrete a variety of spicule shapes, it is difficult to gauge true siliceous sponge diversity and to explore their biostratigraphic utility using only isolated spicules.

This paper deals with Paracalamitina striata (Schmalhausen) Zalessky, 1934, an equisetophyte of the family Tschernoviaceae from the Permian of Angaraland. New material contributes to a better understanding of this plant, which now can be reconstructed. Paracalamitina striata is an equisetopsid with opposite ribs on the stem. Its main stem bears lateral shoots or shoot and leaf scars, that are located at nodes. Shoot nodes have subcylindrical leaf sheaths. The distal parts of leaves are free and acute. Generative organs are fertile zones, which are formed by numerous sporangiophores with peltate sporophylls. A terminal sterile whorl is presented above each fertile zone. An emended diagnosis of Paracalamitina Zalessky is provided on the basis of new material and re-examination of previously collected specimens as well. The nomenclature and taxonomic status of P. striata also are discussed.

A single large specimen of carcineretid crab from the Cretaceous Puerto Romero unit of Colombia constitutes the basis for a new species, Ophthalmoplax triambonatus. A re-diagnosis of the Carcineretidae results in the assignment of five genera to the family: Carcineretes Withers, 1922; Branchiocarcinus Vega, Feldmann, and Sour-Tovar, 1995; Mascaranada Vega and Feldmann, 1991; Ophthalmoplax Rathbun, 1935; and Woodbinax Stenzel, 1952. The cross-sectional profile of O. triambonatus suggests that it was a back-burrower, rather than an active swimmer.

Opisthobranch Gastropods are rare in Mesozoic deposits of Antarctica. The first documented occurrence of opisthobranchs from this continent is from Cretaceous shallow-marine deposits of the James Ross Basin, Antarctic Peninsula, where Wilckens (1910, p. 95–96, pl. 4, fig. 19) described the minute ringiculid Cinulia sp., based on five specimens from two localities on Snow Hill Island. No further work has been done on the Snow Hill Island species. The next mention of Antarctic Cretaceous opisthobranchs was by Zinsmeister et al. (1989, p. 733, fig. 2, p. 734, fig. 3), who cited the occurrence of the ringiculid “Oligoptycha cf. O. concinna Meek and Hayden, 1858,” in the lowermost part of Unit 8 of the López de Bertodano Formation (Maastrichtian) on the southern half of Seymour Island (Fig. 1). We report the first record of Acteonidae from the Mesozoic of Antarctica, Acteon (Tenuiactaeon) antarctihadrum n. sp., discovered in shallowmarine Maastrichtian deposits.

A juvenile specimen of the titanosaurid sauropod Alamosaurus sanjuanensis, recovered from just below the Cretaceous/Tertiary boundary horizon in Big Bend National Park, Texas, is from an individual less than half the size of adult specimens referred to this species. The disarticulated skeleton was preserved in deposits of a shallow flood-plain pond and includes elements not previously described, allowing for an improved diagnosis for this species. The elongate opisthocoelous cervical vertebrae have non-bifid posteriorly deflected neural spines with deep postspinal fossae. The dorsal vertebrae have wide spatulate neural spines with strong prespinal laminae, and lack hyposphene-hypantrum articulations. Alamosaurus sanjuanensis exhibits a unique morphology of the ischium, evident even in this juvenile specimen. Comparison with other titanosaurid species suggests that A. sanjuanensis is most closely related to an unnamed titanosaur from Peiropolis, Brazil and Neuquensaurus australis from Argentina.

Twenty permineralized ovules were recovered from a mixed marine and terrestrial assemblage from the Finis Shale near Jacksboro, Texas, USA. The strata have been dated as Virgilian (upper Pennsylvanian: Gzhelian) based on ammonoid biostratigraphy, regionally correlated based on the marine assemblage, and globally correlated based on ammonoid, fusulinacean and conodont data. These morphotaxa conform to trigonocarpalean ovules based on their three angled symmetry and the presence of a stalked nucellus attached to the integument only at the base. The ovules share many features with the genus Pachytesta but represent a new genus based on their unique exterior shape, integumentary morphology, and vascular system. In addition, these specimens represent the youngest known occurrence of trigonocarpalean ovules, thereby extending their biostratigraphic range. The presence of these plant remains in a regionally and globally correlatable marine assemblage aids correlation of continental strata with established, biostratigraphically time equivalent, marine strata.

The Echinoderm fauna of the Brassfield Formation (Lower Silurian, Early to Middle Llandoverian) contains more than 30 species and is locally common in southern Ohio making it one of the most important Early Silurian faunas known (Foerste, 1919, 1936; Ausich, 1984a, 1984b, 1985, 1986a, 1986b, 1986c, 1987; Ausich and Schumacher, 1984; Ausich and Dravage, 1988). At present, the Brassfield Formation has produced two callocystitid rhombiferans including Brockocystis nodosarius Foerste (1919) and Anartiocystis foerstei Ausich and Schumacker (1984). Neither of these taxa is well-known, being described from a handful of moderately well to poorly preserved specimens each. The discovery of Anartiocystis whitei n. sp., the third callocystitid species known from the Brassfield Formation and second known species of the genus, greatly clarifies the morphology of the genus adding significant information on the plating of the ambulacra and stem.

Crinoid columnals are major faunal components of interbedded shales and carbonates of the Upper Ordovician Kope to Fairview formations (Edenian-Maysvillian) of the Cincinnati Arch region. Six species can be identified on the basis of distinctive morphological characters of the columnals. Crinoid distribution was plotted from point-counted carbonate samples taken through a 68-m thick composite section of the Kope to Fairview formations in Campbell County, Kentucky. This section spans a shallowing-upward, third-order depositional sequence (C1), part of C2, and the Edenian-Maysvillian Stage boundary. The slender cladid crinoid Merocrinus occurs in the lowermost Kope below the base of this section. The slender disparids Cincinnaticrinus and Ectenocrinus occur throughout the section but are most abundant in the lower 25 m where the shale percentage is 60–90 percent. The larger, more robust disparid Iocrinus appears within the carbonate-rich Grand Avenue member of the Kope at 40–50 m, and the large, plated camerate Glyptocrinus first appears just above the Grand Avenue and becomes the dominant crinoid above the C1–C2 sequence boundary that lies just above the Kope-Fairview contact. The largest and most robust crinoid in this sequence, Anomalocrinus, occurs at the top of the Grand Avenue Member. Siliciclastic ratio and biofacies composition indicate that the occurrence of larger, more robust crinoid taxa is correlated with shallowing depth. Crinoid trophic niche differentiation is also correlated with decreasing depth and the concomitant increase in water movement caused by waves and currents. The deeper water disparids have a nonpinnulate filtration fan with low branch density and wider ambulacral grooves. The shallower water camerate Glyptocrinus has a pinnulate filtration fan with high branch density and narrower ambulacral grooves. These relationships are consistent with the predictions of aerosol filtration theory.

The opportunity to study some of de Koninck's (1883) type specimens from the Institut Royal de sciences Naturelle de Belgique (RMNS), specimens from the British Museum of Natural History (BMNH), and from the Museum of Comparative Zoology, Harvard University (MCZ) has provided insight into the taxonomic relationships of some polyplacophoran taxa. It is evident that errors have occurred in relating various specimens to taxa which differ significantly. Two examples of this related to a Devonian species in Germany and a Permian species in the United States National Museum of Natural History (USNM) are clarified and illustrated.

Nerineoids, so typical of the Jurassic and Early Cretaceous in Europe, are usually rare and lacking in diversity in North America north of Mexico. This is especially true of the Pacific slope faunas. Only three species of nerineoid gastropods have previously been reported from the Cretaceous of California (Saul and Squires, 1998). The oldest of these species, Aphanoptyxis andersoni Saul and Squires, 1998, is from the Early Cretaceous (Hauterivian) in northern California. The other two species are Late Cretaceous (Turonian): Aphanoptyxis californica Saul and Squires, 1998, is from northern California, and Nerinella santana Saul and Squires, 1998, is from a locality and strata in southern California near the occurrence of Nerinella califae n. sp. The description of N. califae n. sp. gives California the greatest diversity of Turonian northeastern Pacific slope nerineoids, namely, Aphanoptyxis californica and two species of Nerinella. These Turonian nerineoids are also, thus far, the geologically youngest North American Pacific slope nerineoids.

The Early Cambrian Chengjiang Lagerstätte, Yunnan Province, Southwest China, has become one of the most celebrated Cambrian fossil Lagerstatten not only for perhaps the earliest biota of soft-bodied organisms in the Phanerozoic (Yuan and Zhao, 1999; Zhang et aI., 2001; but see Budd and Jensen, 2000), but also for a number of significant discoveries (Shu et al., 1996a, 1996b, 1999a, 1999b, 2001), proven to be of particular importance for our understanding the Cambrian explosion. Also in Southwest China, Guizhou Province, there is a very significant, although less acclaimed, Middle Cambrian soft-bodied fauna as well, namely the Kaili fauna, which occurs in the Kaili Formation in Kaili area (Kuizhou). The age of the Kaili Formation ranges from late Early to early Middle Cambrian. Regionally, the Kaili Formation is about 222 m thick and consists of three parts. The lowermost part (late Early Cambrian, about 55 m thick) is dominated by thin, calcareous siltstone strata interbedded with limestone layers at the base. The middle part (early Middle Cambrian, ca. 123 m) consists of dark green mudstone and shale, while the uppermost part (ca. 44 m) is composed of interbedded limestone and silty shale. The Kaili fauna is derived from mudstones in the middle part of the formation (Zhao et aI., 1994; Zhu et aI., 2000).

Karagandoceratids are a rare offshoot of the Prionoceratinae, resembling that subfamily in general conch form and sutural ontogeny, but differing by possession of an acute ventral margin and an increasingly trifid ventral lobe. The systematic position of the Karagandoceratidae has been controversial [see Bartzsch and Weyer (1988) for an exhaustive review]. The nominate genus, Karagandoceras Librovitch, 1940 (type species, K. galeatum), possesses a weakly divided ventral lobe which has led authors to refer it to both the Praeglyphioceratina (Ruzhencev, 1960, 1962; Bogoslovsky, 1971; Ruzhencev and Bogoslovskaya, 1978; Bogoslovskaya et al., 1999; Kusina, 2000) and the Goniatitina (Weyer, 1965, 1972; Kullmann, 1981). Discovery of an ancestral karagandoceratid genus, gen. nov. I aff. Karagandoceras Bartzsch and Weyer, 1988, in the early Tournaisian Siphonodella sandbergi conodont Zone in Germany provided clarification on the proximate origin of Karagandoceras and provided a plausible link to the early Tournaisian prionoceratin genus Nicimitoceras Korn, 1993 (type species, Imitoceras subacre Vöhringer, 1960). Bartzsch and Weyer (1988) proposed a karagandoceratid phylogeny beginning with gen. nov. I aff. Karagandoceras in the early Tournaisian, progressing through Karagandoceras in the middle Tournaisian, and culminating with a third, descendent genus, gen. nov. II aff. Karagandoceras (typical species, Karagandoceras bradfordi Manger, 1971), early in the late Tournaisian. Bartzsch and Weyer (1988) elected to leave both the initial and final members of this lineage, gen. nov. I and gen. nov. II aff. Karagandoceras, in open nomenclature pending discovery of more completely preserved material. Discovery of superbly preserved representatives of a new species of gen. nov. II aff. Karagandoceras from the Borden Formation in northeastern Kentucky provides additional sutural and morphological details that support Bartzsch and Weyer's phylogenetic interpretation and makes formal description of this terminal karagandoceratid taxon (herein designated Masonoceras new genus) possible.

Graptolites are relatively uncommon fossils in the Middle and Upper Ordovician carbonates of the North American mid-continent. With the notable exception of the Viola Springs Formation in Oklahoma, most units contain a single species, which occur within narrow stratigraphic intervals (often single beds). While uninteresting in terms of their diversity, these monospecific collections commonly yield excellent three-dimensionally preserved specimens that can be isolated from their matrix and studied. In particular, the large number of well-preserved specimens allows for accurate evaluations of intra-specific variation and reliable descriptions of taxa that are generally known from flattened or otherwise distorted material. Additionally, these graptolite collections can provide important biostratigraphic ties between disparate facies—shallow mid-continental limestones and the deeper-water black shales characteristic of continental margins.

The abundant fusulinids of the Hughes Creek Shale Member of the Foraker Limestone in east-central Kansas are noted for their excellent preservation (Hageman and Kaesler, 1998). Not all these fossils are in pristine condition, however, as taphonomy has taken its toll. We deal in part with necrolysis during predation, but we examine more specifically instances in which predation failed and the fusulinid survived to repair damage to its test.

A relatively large new specimen of the callocystitid rhombiferan Novacystis hawkesi Paul and Bolton, 1991, is described from the Wenlock (Middle Silurian) Thornloe Formation of east-central Ontario. This new specimen adds to the known morphology of Novacystis hawkesi, including the plating of the thecal side opposite the periproct, the presence of four pectinirhombs in standard callocystitid placements, and brachiole morphology. It also confirms the unusual placement of the periproct previously described for this species. A phylogenetic analysis of Callocystitidae indicates that, as presently defined, Callocystitinae sensu Paul and Bolton is polyphyletic and Apiocystitinae is paraphyletic. Novacystis forms part of a small, relatively primitive echinoderm fauna, probably of middle Wenlock age from the Timiskaming area, suggesting that shallow cratonic areas of the Canadian shield area may have served as refugium for archaic echinoderm taxa.

Small phosphatic fossils recovered from acid residues of the Galena Group Middle (Ordovician) of Wisconsin were recently described by Clark et al. (1999) as weird things. Here, we report that specimens identified by those authors as Thing 3 and Thing 6 are fragments of conulariids belonging to two species that occur widely through Middle Ordovician strata of eastern North America. Similarly disintegrated, conspecific specimens from the Trenton Limestone of northwestern Indiana, and articulated, conspecific specimens from Ohio and New York, are introduced for comparison.