The Permian–Triassic boundary, examined at two sections in the Southern Alps, occurs ~ 1.0 to 1.5 m above the base of the Tesero Oolite Member of the Werfen Formation in a depositionally continuous sequence of inner neritic carbonates. Lagenide foraminifers from the boundary interval comprise 27 species in 15 genera plus additional unidentified taxa, most of which became extinct during the end-Permian crisis. The only survivors were “Nodosaria” elabugae and unidentified species in Geinitzina and Nodosinelloides, with representatives of the latter two genera being short-term holdovers. The end-Permian lagenide extinction level occurs a few decimeters below the biostratigraphically defined erathem boundary, just above the contact between the Bulla Member of the Bellerophon Formation and the overlying Tesero Oolite Member. Confidence intervals (>96%) for the lagenide extinction at the two sections are 0.03 and 0.04 m thick. Plots of species' stratigraphic abundance versus their last observed occurrences below the estimated extinction intervals at both localities are consistent with abrupt extinction or gradual extinction lasting no more than the time required for 1 m of rock to accumulate. Blooms of the foraminiferal disaster taxa Rectocornuspira kalhori and Earlandia sp. occur in the extinction interval and continue well into the Dienerian part of the Mazzin Member of the Werfen Formation, consistent with a protracted survival phase. A detailed carbon isotope record has been obtained from rocks bracketing the extinction at the well-known Tesero section. The combined microfossil and carbon isotope data indicate that the extinction occurred during an initial negative shift in δ13C. Therefore, the negative excursion is likely to be related to the cause of extinction and unlikely to be merely a consequence of extinction.

The Upper Cambrian sponge Wilbernicyathus donegani Wilson, 1950 was originally described as an archaeocyath. The original specimens were lost. Later, based on the original description and figures, this species was interpreted as an orchocladine lithistid, but family-level taxonomy has not been clear. A neotype is designated to help stabilize the taxonomy of this species. A redescription based on the neotype and other new material from the area of the type locality and elsewhere demonstrates that this species is an orchocladine lithistid sponge belonging to the family Anthaspidellidae. It has a regular skeleton consisting of dendroclones and trabs arranged in a ladderlike net, and radial canals are well organized. The species occurs within sponge-microbial and stromatolitic reefs in the Wilberns Formation of central Texas and possibly the Clinetop Bed of the Dotsero Formation of Colorado. Stratigraphically, it ranges from the Idahoia to the Saukia trilobite zones of the Upper Cambrian Ptychaspid Biomere. Ecologically, Wilbernicyathus Wilson, 1950 occupies a reefal niche and constitutes up to 30% of the reef volume. These Late Cambrian bioherms represent the initial Laurentian expansion in the sponge-microbial buildups that dominated reef environments worldwide during the Early Ordovician.

The morphology of Tuzoia is reinterpreted in the light of abundant new specimens from the Middle Cambrian Burgess Shale (British Columbia, Canada) and Kaili (Guizhou, China) Lagerstätten. Tuzoia was a very large (up to 180 mm long) bivalved arthropod with a nonmineralized domelike carapace strengthened by prominent pointed features and often flanked by a lateral ridge bearing a spiny frill. The reticulate pattern of Tuzoia is comparable with that of present-day crustaceans (e.g., myodocope ostracods) and is interpreted as a structural compromise between exoskeletal lightness and high resistance to mechanical stress. Tuzoia had a pair of large, stalked, spherical, possibly compound eyes facing forward. Flagella-like antennae protruded through the anterior notch. No other appendages are known except possible filamentous setae underlying the carapace. Tuzoia typically occurs as laterally (lc) or dorsoventrally (dvc) compacted carapaces or single valves. Each type (lc or dvc) emphasizes particular aspects of the morphology (e.g., spiny lateral ridge, ventral margin) that were often interpreted as specific differences by previous authors. A revision of Tuzoia validates only 7 of the 23 named species. Tuzoia is placed tentatively within a group of large bivalved arthropods along with Isoxys and the possible ancestors of Thylacocephala (Lower Cambrian–Upper Cretaceous). In the Middle Cambrian, Tuzoia occurs across Laurentia, South and North China, and the Perigondwanan area (Bohemia) within a relatively narrow subtropical belt, indicating a high dispersal capability and possible latitudinal control on its distribution. Functional morphology, taphonomy, and the distributional pattern indicate that Tuzoia was a free-swimming arthropod.

A new species of the Montastraea “annularis” species complex is herein described from Pleistocene coral reefs of the Caribbean Sea. The species, Montastraea nancyi n. sp., had a broad geographic distribution at mainly insular sites 125 Ka. It has a fossil record extending from >600 Ka (thousand years) to 82 Ka, both first and last occurrences exclusively on the island of Barbados. It also had a broad environmental tolerance, occurring in fringing, windward back-reef and reef-crest, leeward reef-crest, and lagoonal patch-reef environments. In every habitat in which it lived, there are examples that it either dominated the coral fauna or shared dominance with Acropora palmata, a dominant shallow water coral in high-energy Pleistocene and modern reefs. The extinction of Montastraea nancyi resulted in evolutionary and ecological change in surviving members of the M. “annularis” species complex.

Two new species of the rhynchonellid brachiopod Probolarina are described, Probolarina neoleonensis new species and Probolarina papalotensis new species. They were collected from a Paleocene limestone lens associated with a diapir in the La Popa basin, northeastern Mexico. Thousands of these brachiopods occur in this lens and constitute the first report of brachiopods for the Difunta Group, from which a diverse paleobiota has been previously reported. This occurrence represents the oldest record for the genus in the Western Hemisphere, as the only other Paleocene occurence of this genus was reported from New Zealand. Recent studies suggest that the carbonate lentil from which the brachiopods were collected were deposited in the shadow-effect area adjacent to the diapir, which affected the sediment influx into the basin.

The Late Ordovician and Early Silurian conodont faunas of northeast Russia are described, based on 39 conodont-bearing samples collected from Kanyon, Padun, Tirekhtyakh, Maut, and lower Sandugan Formations at Mirny Creek and Ina River sections, Omulev Mountains. The faunas are represented by a total of 776 identifiable conodont specimens assigned to 35 species representing 25 genera, among which a new species, Periodon mirnyensis, is established. Based on graptolite zones at the same locality and other conodont faunas worldwide, the faunas are assigned to the Caradocian, early Ashgillian, late Ashigillian, early Llandovery, and late Llandovery. The Ordovician faunas belong to outer platform to upper slope facies with a North Atlantic Realm affinity; the Silurian faunas are from slope and basin facies. The conodont faunas are the first to be described from the Kolyma Terrane, which has an enigmatic paleogeographic position during the Early Paleozoic.

The Horse Spring conodont succession in the Canning Basin replicates zones 6 through 13 of the thirteen-fold Frasnian zonation. Horse Spring, together with other Canning Basin sections, demonstrates the widespread application of the zonation. Furthermore, the recently formalized three-fold subdivision of Zone 13, which has been recognized in the Montagne Noire, Moroccan Meseta, and northern Ontario, is developed at Horse Spring and other Canning Basin sections.

The Canning Basin Frasnian is noteworthy for the high quality of preservation of the conodont faunas, the extremely low CAI values, and the abundance of elements in most collections. The emphasis in this paper is on the taxonomy of Frasnian Palmatolepis. Newly described species are: Palmatolepis beckeri, P. feisti, P. housei, P. klugi, P. nicolli, P. playfordi, P. uyenoi, and Polygnathus kirchgasseri. Complete and partial multielement apparatuses have been reconstructed for Palmatolepis playfordi and P. nicolli.

New material of polyglyphanodontine lizards from the Late Cretaceous has been found in various localities in western North America. Several transversely oriented teeth representing a new species of Dicothodon were recovered from the Turonian of southern Utah. These specimens necessitate reassignment of Polyglyphanodon bajaensis to Dicothodon (Polyglyphanodon) bajaensis. From the Campanian of Utah, additional teeth and jaw fragments referable to Manangysaurus saueri have been recovered and this species is reassigned here to Peneteius (Manangysaurus) saueri. Also, an isolated tooth referable to Peneteius has been recovered from the Campanian of southern Texas. The results of a phylogenetic analysis support a monophyletic grouping of the transversely-toothed taxa with Bicuspidon as the sister taxon of Polyglyphanodontini new taxon, which is comprised of Polyglyphanodon, Dicothodon, and Peneteius. The phylogenetic analysis also places “teiid” lizards from the Cretaceous of Asia and North America in a monophyletic group, Borioteiioidea new taxon, which is the sister taxon to the Teiioidea (Teiidae + Gymnophthalmidae). This new hypothesis of the interrelationships of these taxa requires the reevaluation of several characteristics that were previously considered diagnostic for a more inclusive Teiidae. Another implication of our results is that Teiidae (sensu stricto) has no demonstrable pre-Tertiary occurrence. It appears that Teiioidea and Borioteiioidea diverged from a common ancestor by the Early Cretaceous. The Teiioidea entered South America and are currently represented by the Teiidae and Gymnophthalmidae, whereas Borioteiioidea radiated throughout North America with subsequent dispersal to Asia and Europe.

Seven fossil leaf species are described from impression fossils collected from the Upper Cretaceous (Maastrichtian) Fox Hills Formation in south-central North Dakota, USA. They are Marmarthia johnsonii n. sp., Nilssoniocladus yukonensis n. comb., Nilssoniocladus comtula n. comb., Mesocyparis borealis, Rhamnus salicifolius, Paloreodoxites plicatus, and Zingiberopsis magnifolia. These species represent some of the elements of the Fox Hills flora that have paleogeographic ranges to the northwest (N. yukonensis, N. comtula, and M. borealis) and to the southwest (M. johnsonii, R. salicifolius, P. plicatus, and Z. magnifolia) of the Fox Hills type area. The identification and reappraisal of these species represent an effort to understand the biogeographic relationships of Late Cretaceous floras across the Northern Hemisphere.

Two leaves of Quercus simulata Knowlton from the Miocene of Oregon each show a new type of cynipid gall. Antronoides cyanomontanus n. sp. is described from six elongate and narrowly spindle-shaped galls, 7.0 mm long, and 2.0 mm wide tapering to a narrow tip. They have expanded rim-like bases with most galls scattered throughout the midsection adjacent to or partially straddling a secondary vein. Antronoides oregonensis n. sp. is known from 20 galls, 4.0-5.0 mm long, 1.8-2.0 mm wide and weakly clavate, appearing C-shaped with a rounded apex and circular to oval-shaped base. Galls occur primarily in the basal third of the leaf in a single file along each side of the midrib. Contrary to previous studies, we found A. schorni Waggoner and Poteet, A. polygonalis Waggoner, and A. cyanomontanus to be morphologically closer to Cynips cornifex Hartig on Q. pubescens (European white oak), whereas the new gall A. oregonensis most closely resembles X. clavuloides. The presence of Antronoides indicates the evolution and dispersal of Cynipini wasps was well underway in western North America by the Miocene. However, the new galls leave open the possibility that X. clavuloides and related species may have evolved during the Paleogene in higher-latitude mesic forests of western North America, rather than in the southern Great Basin as suggested by Kinsey and Waggoner and Poteet.

Bryozoans were collected from a thin shaley limestone in the lower part of the Bird Spring Formation in the northern part of the Muddy Mountains, Clark County, southern Nevada (Fig. 1). The purpose of this paper is to describe a new genus and two new species of these bryozoans. The fauna of the Bird Spring Formation has taken on a new importance with the formation's designation as the Global Boundary Stratotype Section and Point (GSSP) for the Mid-Carboniferous Boundary (Lane et al., 1999). Samples were collected from the bryozoan-bearing unit while teaching field camp during the spring of 1994.

The enigmatic Silurian fossil Bunodella horrida Matthew, 1889 was originally described as a crustacean (Matthew, 1889). B. horrida was later included with the pseudoniscid synziphosurines by Størmer (1955) in the Treatise on Invertebrate Paleontology. Bunodella Matthew, 1889 was subsequently dismissed as a merostome in later treatments (Eldredge, 1974; Anderson and Selden, 1997). However, the type and only known specimen (Fig. 1), housed in the New Brunswick Museum (NBMG), has not been re-studied since Matthew's initial description. Reexamination of this fossil has led us to interpret it as the partial coxa of a pterygotid eurypterid swimming leg. The coxa is likely to belong to Acutiramus Ruedemann, 1935 rather than any other pterygotid, but it cannot be further separated from other species in the genus and is left as Acutiramus sp. A more precise assignment must await more diagnostic material (e.g., chelicerae). The genus Bunodella Matthew, 1889 is therefore deemed invalid and its usage discontinued. Bunodella Pfeffer, 1889 was also established as a genus of a modern hexacoralline anemone based on a single species, B. georgiana Pfeffer, 1889, but has since been reassigned to the genus Parantheopsis McMurrich, 1904 by Carlgren (1949) along with several other species of anenome.

Until recently considered a rare Appalachian Basin endemic, Pennoceras Miller and Unklesbay, 1942 has emerged as one of the most widespread and locally abundant ammonoids in the lower Missourian of the Midcontinent (Boardman et al., 1994). Here we document the first Midcontinent record of the type species of Pennoceras, P. seamani Miller and Unklesbay, 1942, from the Hushpuckney Shale equivalent in southeastern Kansas. Additional, previously undescribed species of Pennoceras from the Exline Limestone and Mound City Shale equivalents in Oklahoma and southeastern Kansas are described as Pennoceras bennisoni new species and Pennoceras heckeli new species. Discovery of these ancestral species provides clarification on the derivation and early history of Pennoceras and provides a possible link to the Desmoinesian Wiedeyoceratidae.

Sawfishes of the family Pristidae comprise a group of rays having dorsoventrally flattened, sharklike bodies and elongated rostra bearing a row of teeth on each side. Some species may attain total body lengths (TL) of 7 m or more (Compagno and Last, 1999). Unlike the similarly-shaped sawsharks of the family Pristiophoridae, the number of rostral teeth and their proportions are established in utero and maintained into adulthood (Slaughter and Springer, 1968; Miller, 1974), and if a tooth is lost the alveolus remains empty. In addition, the gills are located on the underside of the body and there are no rostral barbels (Tricas et al., 1997; Compagno and Last, 1999). Recent Pristidae consists of five to seven species (depending on synonymy) within two genera, Pristis (Linck, 1790) and Anoxypristis (White and Moy-Thomas, 1941).

The family Mixosauridae Baur, 1887 is a dominant group of Middle Triassic ichthyosaurs. Its generic composition has been controversial, but recent findings from southern China enabled Jiang et al. (2006) to recognize two monophyletic taxa within the clade, suggesting the presence of two genera within the family, namely Mixosaurus Baur, 1887 and Phalarodon Merriam, 1910. The latter genus, which was invalidated at one point (Nicholls et al., 1999; McGowan and Motani, 2003), was recently resurrected by Schmitz (2005) by validating its type species. Mixosaurus is Tethyan in distribution, whereas Phalarodon had been known mostly from North America and Spitsbergen, apart from a possible juvenile from Switzerland (Brinkmann, 1997, 1998). More recently, Jiang et al. (2003) reported a largely complete, yet poorly preserved skeleton as the first record of the genus Phalarodon from Asia and referred it to Phalarodon sp. However, important synapomorphies were not clearly identified, and evidence has since emerged that the specimen had been tampered with by farmers after it was collected. In the light of the cladistic analysis by Jiang et al. (2006), the referral of the specimen to the genus Phalarodon is questionable.