The concept of the Ordovician gastropod genus Maclurites Le Sueur, 1818, at present includes much variation. Maclurina Ulrich in Ulrich and Scofield, 1897, is removed as a subjective synonym of Maclurites and reestablished as a separate genus. Species of Maclurites with spiral grooves on the outer whorl surface and a relatively small umbilicus are transferred to Maclurina. Maclurina manitobensis (Whiteaves, 1890) forms a distinctive part of the Late Ordovician-age “Arctic Ordovician fauna.” An unusually large specimen (25 cm in diameter) from the Bighorn Dolomite (Upper Ordovician), Wyoming, is illustrated; this Wyoming specimen is the volumetrically largest Paleozoic gastropod ever reported.

Many specimens of the conulariid Paraconularia magna (Ries) from the Tackett Formation (Upper Pennsylvanian, Missourian) of Oklahoma exhibit repaired or unrepaired injured exoskeletons. Scalloped, cleft, and embayed patterns are interpreted to be repaired sublethal damages produced by unknown events or organisms. Punctures, which are the first reported in conulariids, were not followed by exoskeletal repair and were probably lethal. Cladodont sharks are implicated as possible predators of P. magna because of a close correspondence in size and pattern between the dentition of some sharks and the punctures preserved in conulariid exoskeletons.

Two new genera, Anisaeger and Distaeger, and three new species, Anisaeger brevirostrus, A. spiniferus, and Distaeger prodigiosus, extend the range of the Aegeridae (Dendrobranchiata, Penaeoidea) into the Middle Triassic (Anisian) of China. Seven decapod crustacean species are now known from the Luoping biota of southern China. Morphological features of shrimp that are present but rarely mentioned in the neontological literature are recognized as potentially useful in classifying fossil material, including a diaeresis on the exopod of the uropods and multiarticulate flagellae on pleopods. Unusual taphonomic features of the shrimp include fractured cuticle, preservation in lateral, dorsal, and ventral position, and twisted cephalothoraxes.

Ocean Drilling Program (ODP) Holes 980 B and C, Feni Drift at the eastern slope of the Rockall Plateau, eastern North Atlantic, were examined for late Quaternary deep-sea ostracode taxonomy. Nineteen genera and 32 species were examined and (re-)illustrated with high-resolution scanning electron microscopy images. One new species Cytheropteron paramassoni n. sp. is described and one new name Eucytherura zehali is proposed for Eucytherura hazeli Yasuhara et al., 2009. This study provides updated taxonomic information for deep-sea ostracode genera and species from the eastern North Atlantic, which is an important baseline for application of deep-sea ostracodes to paleoceanographical reconstructions and paleoecological studies in this region.

A new collection of fossil decapod crustaceans from the Cretaceous Rosario Formation, the Eocene Tepetate Formation and the Oligocene El Cien Formation, Baja California Sur, Mexico, has yielded two new genera and several new species, Amydrocarcinus dantei n. gen. and sp., Levicyclus tepetate n. gen. and sp., Eriosachila bajaensis n. sp., Oregonia spinifera n. sp., Archaeopus mexicanus n. sp., and Necronectes nodosa n. sp. Additionally, new occurrences of the previously described Lophoranina bishopi, Xandaros sternbergi, Icriocarcinus xestos, and Lobonotus mexicanus as well as Dardanus cf. D. mexicanus are reported. As part of ongoing work on global evolutionary and paleobiogeographic patterns within the Decapoda, the work has prompted a review and synthesis of decapod occurrences in the tropical and subtropical Americas including the southern United States, the Caribbean, Mexico, Central America, and northern South America. As a result of the systematic review, several new combinations are reported herein which include Eriosachila bartholomaeensis (Rathbun, 1919), Lobonotus sandersi (Blow and Manning, 1996; 1998), and Matutites americanus (Rathbun, 1935). Icriocarcinus is transferred to the Goneplacidae, extending the range of that family into the Cretaceous. Most Cretaceous through Miocene tropical and subtropical American taxa appear to have originated within the area and a large number were endemic. Most of the immigrants to the central Americas appear to have evolved along North Atlantic shelves and subsequently dispersed to the Americas, probably via continental shelf routes. In addition, as demonstrated by several previous studies, decapod crustaceans appear to have evolved in numerous middle- and high- latitude areas with subsequent dispersal to lower latitudes, contrary to the long held notion that the tropics are areas of origin with subsequent dispersal to other regions. Low-latitude decapod taxa tend to remain in low-latitude areas. The Maastrichtian and the Eocene appear to have been times of elevated extinctions within the Decapoda; however, the extinction patterns for those two time intervals are very complex.

Bison antiquus Leidy, 1852 was one of the largest and most widely distributed megafaunal species during the Late Pleistocene in North America, giving rise to the modern plains bison in the middle Holocene. Despite the importance of the ancient bison, little is known about its feeding ecology. We employed a combination of extended mesowear, and mesowear III to infer the dietary preference and habitat use of three Mexican samples of B. antiquus. These included two northern samples—La Piedad-Santa Ana and La Cinta-Portalitos—from the Transmexican Volcanic Belt morphotectonic Province, as well as one southern sample—Viko Vijin—from the Sierra Madre del Sur morphotectonic province. We found that the northern Mexican samples were primarily nonstrict grazers, whereas the southern sample displays a pattern consistent with mixed feeding habits. This suggests variability among the diets of the bison from these samples, caused by different paleoenvironments. This evidence complements the paleoenvironmental reconstructions in the studied localities; for the northern samples, open prairies composed of patches of woodland or shrubland and, for the southern locality, a fluvial floodplain with short-lived vegetation. In both scenarios, grasses (Poaceae) were nondominant. The dietary habits of our samples of ancient bison in Mexico are the southernmost dietary inference for the species in North America and expand our knowledge of the dietary habits of B. antiquus during the Late Pleistocene.

Subduction-Related Hydrocarbon-Seep carbonates in Cenozoic deepwater sediments in western Washington State, USA, yield fossil invertebrate communities that are largely endemic to these localized microhabitats (Goedert and Squires, 1990; Peckmann et al., 2002; Goedert et al., 2003; Kiel, 2006). An unusually large species of the deep-sea gastropod Abyssochrysos Tomlin, 1927 has been described from the oldest of these seep carbonates, which occurs in the Humptulips Formation on the southern slopes of the Olympic Mountains (Goedert and Kaler, 1996). New material of this species was recently collected at this site and shows that this species has a deep notch and a selenizone at the base of the outer lip, a feature that is very unusual among living gastropods, and unknown from Abyssochrysos. This feature is also present on two gastropod specimens, found in the collection of the Burke Museum (UWBM) that are, according to the label, from the Humptulips area but without detailed locality information. Stable isotope analysis of the micritic matrix adhering to the specimens showed δ13C values as low as −37 to − 41‰ relative to PDB standard. Such negative values clearly indicate that the carbonate formed under the influence of anaerobic oxidation of biogenic methane (cf. Whiticar, 1999; Peckmann et al., 2002). The isotope analysis was carried out in the same lab using the same methods as described in Kiel (2006). The Humptulips area is currently covered with dense vegetation and attempts to locate the carbonate outcrop where these two specimens could have come from have been unsuccessful. The purpose of this note is to introduce a new genus for this unusual species, to discuss its possible place among the gastropods, and to speculate about the function of the two deep sinuses in the outer lip of the aperture.

Rhynchonellida is the stratigraphically oldest and phylogenetically most basal of the extant rhynchonelliform brachiopod orders, yet phylogenetic relationships among rhynchonellides are poorly known. The fourteen named rhynchonellide superfamilies (four of which have extant representatives) were defined primarily on the basis of features of the dorsal cardinalia, particularly crural morphology, but their homology and polarity have not been investigated rigorously. Superfamily monophyly is unclear, as is the evolution of several distinctive rhynchonellide morphological features, such as crura.

The purpose of this study is to investigate the phylogenetic relationships among extant rhynchonellide genera using skeletal characters, and to compare the results with the current classification, elucidating the evolution of morphological features in the process. We completed parsimony-based and Bayesian analyses using fifty-eight characters of the interior and exterior of the shell that vary among the nineteen extant genera. Our results are readily interpretable with respect to the classification, and indicate that Hemithiridoidea, Dimerelloidea, and (in some analyses) Pugnacoidea appear to be monophyletic. Species classified in Dimerelloidea and Pugnacoidea, and in certain cases Hemithiridoidea, each form derived subclades that evolve from within a paraphyletic Norelloidea at the base of each subclade. Raduliform crura appear to be the most basal, phylogenetically; five other crural morphologies evolve from the raduliform state. However, morphological characters currently uniting genera in rhynchonellide superfamilies are not clearly diagnostic and exhibit a relatively high degree of homoplasy overall, suggesting that consistency with the classification may be based on a false sense of confidence in rhynchonellide morphology to clearly elucidate evolutionary relationships. Published molecular phylogenetic hypotheses conflict with the morphological topologies, further supporting this possibility.

The evolutionary trends among diagnostic characters of Recent rhynchonellides appear to reflect successive juvenilization in adult morphology in several subclades, suggesting that heterochrony may have played an important role in the evolution of the group.

Disklike, firm, bilaterally symmetrical fossils recovered from the middle Lower Cambrian Amouslek Formation of the Moroccan Anti-Atlas are described under the name Microschedia amphitrite n. gen. and sp. Their systematic affinity, particularly to brachiopods and cnidarians, and resemblance to existing taxa are discussed. Although interpretation as a brachiopod appears to be more convincing, their morphology does not permit a precise determination of systematic position.

Fossils of a new primitive plesiadapid primate, Pronothodectes gaoi n. sp., from the middle Tiffanian (late Paleocene) Paskapoo Formation of Alberta, Canada, are described. Pronothodectes gaoi, the youngest known species of the genus, has P3–4 and lower molars that are intermediate between those of the early to middle Tiffanian successional species Plesiadapis anceps Simpson and Plesiadapis rex (Gidley) both in size and qualitative characters. Pronothodectes gaoi retains I2 and the lower canine, as do all species of Pronothodectes Gidley but not Plesiadapis Gervais. A possible second species of Pronothodectes, from the earliest Tiffanian Cochrane 2 locality, Alberta, more closely resembles the ancestral Plesiadapis, Plesiadapis praecursor Gingerich, in size and configuration of P4, M1–3, but not in dental formula since the lower canine and perhaps I2 are retained. The stratigraphic occurrences of the fossils described here show that ancestral plesiadapids having I2 and the lower canine did not evolve anagenetically into Plesiadapis at the Torrejonian–Tiffanian boundary, as had been previously believed and that knowledge of the infrequently known anterior lower dentition may be necessary for recognition of some, otherwise indistinguishable, plesiadapid species. These discoveries make both interpretation of early plesiadapid phylogeny and correlation based on the stratigraphic succession of early plesiadapid species uncertain.

A single specimen of Cyclolobus persulcatus Rothpletz (1892), a species interpreted as a primitive member of the genus, is described from the Cherrabun Member of the Hardman Formation, Liveringa Group, Canning Basin, Western Australia. It is the youngest Permian ammonoid known from Australia. Type and other representatives of C. persulcatus from Indonesia (Timor) are part of the “Amarassi fauna,” which is considered post-Guadalupian. Cyclolobus is sporadically abundant and widely distributed in the Dzhulfian Stage, and probably extends into the overlying Dorashamian Stage.

The Giant Rat Kangaroos (Ekaltadeta, Propleopus) were placed in a new subfamily the Propleopinae by Archer and Flannery (1985). The discovery of new Ekaltadeta material from Riversleigh, northwestern Queensland has stimulated a review of propleopine phylogeny. Cladistic analysis of five propleopine taxa suggests possible paraphyly for Ekaltadeta and polyphyly for Propleopus. A new species of Miocene propleopine, Ekaltadeta jamiemulvaneyi n. sp., from system C local faunas at Riversleigh, is described.

Some species of late Paleozoic bellerophontacean gastropods attained unusually large sizes. Yochelson (1960) described several Permian species from the American Southwest having shells more than 50 mm long, and noted that the largest North American specimen is an incomplete Leonardian steinkern more than 90 mm long, from the Glass Mountains of Texas. A Permian species of Bellerophon from Japan is up to 120 mm wide (Yochelson, 1960), and several Mississippian and Pennsylvanian species in the 90+ mm range are also known (Weir, 1931; Kues, 1987). Steinkerns of this size are not uncommon in Wolfcampian and Leonardian formations in New Mexico, but because of lack of preserved shell material and/or occurrence in massive limestones they are rarely collected and little is known about them. In this note we report and illustrate an unusually well preserved but incomplete Guadalupian bellerophontid from southern New Mexico. It is considerably larger than the specimens mentioned above, and appears to be the largest late Paleozoic bellerophontid yet reported.

Octapyrgites elongatus n. gen. n. sp., a relatively rare, tetraradial olivooid (Cnidaria, Medusozoa), is described from Bed 5 of the Yanjiahe Formation (Cambrian Stage 2) near Yichang, China. Although similar to Olivooides and Quadrapyrgites from the Fortunian Stage in consisting of a partially corrugated (longitudinal) periderm with a quadrate (transverse) apical portion and V-shaped apertural lobes, O. elongatus is substantially larger than other olivooids. The elongate apical region of O. elongatus is similar to four-sided Anaconularia anomala (Barrande, 1867), though with a flat tip that may have been an adaption for a sessile mode of life. As in other olivooids, embryonic development in O. elongatus may have been direct. Last, the paucity of olivooids and the absence of pentaradial cnidarians and carinachitids in Cambrian Stage 2 indicate a marked decline in the disparity of cnidarians near the Fortunian–Cambrian Age 2 boundary, when by contrast bilaterians underwent rapid diversification.

UUID: http://zoobank.org/60acc2f9-44f8-4a97-9449-960ad76f8fff

The systematic position of the Ordovician calcareous microfossil Halysis Høeg, 1932 has long been uncertain. Only known from thin sections, its morphology has been suggested to be either a single chain of cells or a series of tubes and it has been regarded as a green alga or cyanobacterium. Here we propose that Halysis represents a single sheet of cells. This new morphological interpretation accounts for Halysis's appearance in thin section as an extended flexuous series of cells, some of which are not seen to be in mutual contact, exhibiting nonlinear cell-size variation. It is also consistent with the absence of tubiform sections unequivocally attributable to Halysis. This reassessment suggests comparisons between Halysis and Mesozoic–Cenozoic thin laminar unistratose coralline red algae. Halysis cells are relatively large (40–210 µm), but their lower range is comparable to cells of corallinaceans such as Lithoporella (Foslie) Foslie, 1909. Applanate thallus morphology in Halysis resembles that of thin laminar species of Lithophyllum Philippi, 1837 that were traditionally included in Titanoderma Nägeli, 1858. Interpretation of Halysis as a coralline-like alga strengthens the likelihood that a variety of corallines was present in the Ordovician, more than 300 Ma prior to the currently recognized major diversification of this important group of red algae in the Cretaceous.

Cambrothyra ampulliformis Qian and Zhang, 1983, is a jar- or vase-shaped fossil known from the Lower Cambrian of Shaanxi and Hubei provinces, China. It has been interpreted as a protistan test or cyst or a metazoan sclerite. A large collection of specimens from the Xihaoping Member of the Dengying Formation in southern Shaanxi Province permits its detailed redescription. These fossils are highly variable in shape but this variation is continuous and does not support the current recognition of multiple species for this material. They were originally hollow with a restricted basal foramen and a calcareous wall probably composed of fibrous aragonite. All of these features support the identification of Cambrothyra as sclerites of a coeloscleritophoran, a problematic group of Cambrian scleritome-bearing metazoans. Furthermore, the walls of Cambrothyra sclerites contain numerous pores, a feature shared with other coeloscleritophorans. Cambrothyra resembles chancelloriids in particular due to the shared presence of a verruculose texture around the foramen and the absence of mirror-image pairs of asymmetric sclerites. However, unlike chancelloriids, which have rosette-like compound sclerites, the scleritome of Cambrothyra was dominated by isolated sclerites, with only a few pairs and clusters of sclerites and twin sclerites. Consequently, we hypothesize that Cambrothyra forms a clade with other chancelloriids, but represents a basal lineage that plesiomorphically retained isolated sclerites. The morphology of Cambrothyra sclerites, which shares features with both chancelloriids and halkieriids, thus supports the hypothesis that all coeloscleritophorans form a natural group.

Extraordinarily well-preserved pithonellid microfossils (calcitarchs, “calcispheres”) from the Turonian (upper Cretaceous) of Tanzania reveal previously unknown morphological traits, crystallographic patterns, and chemical signatures, providing new insight to this enigmatic group of microfossils. Using combined transmitted-reflected light microscopy, scanning electron microscope imagery, electron microprobe elemental analysis and stable isotope geochemistry, the present study reveals four new aspects of the genus Pithonella, notably, the following. An affinity with cyst-forming organisms, potentially the dinoflagellates, is indicated by the presence of a hatch opening and corresponding operculum. The pristine outer wall architecture consists of thin, smooth shingle-shaped plates with regular rows of slit-shaped pores and an apical sub-angular or circular pore. This primary surface pattern is significantly different from previous descriptions of an outer wall consisting of “parquet-shaped” prismatic crystal rows; this latter surface pattern is formed by secondary overgrowth. The crystallographic pattern of the inner wall is crypto-crystalline. Unaltered pithonellids reveal a calcite chemistry characterized by comparably high Mg-contents, relatively enriched stable carbon isotope values, and stable oxygen values indicating a surface water habitat. Based on these previously unseen traits, the diagnosis of the genus Pithonella is emended. A new species, Pithonella diconica, is described from the lower-middle Turonian sediments of Tanzania.

Late Carnian–early Norian corals from the Luning and Osobb formations in west-central Nevada represent an important Late Triassic fauna for understanding the paleoecology and the paleogeography of the eastern Panthalassa region during Late Triassic time. The corals occur in bedded limestone representing biostromes and patch reefs and their composition presages the important global changeover of faunas of the intra-Norian interval. A taxonomic analysis of over 60 specimens reveals a majority of colonial corals ranging from cerioid, astreoid (i.e., cerioid-plocoid lacking walls), meandroid and thamnasterioid types. Surprisingly, remnants of the original aragonite microstructure remain in some specimens, allowing a better comparison with more remote Tethyan corals. In total, 14 genera have been identified from Nevada while two genera remain undetermined. The fauna is composed of species considered typical of both the North American Cordillera and cratonal South America. The following genera and species are new and endemic to the Americas: Khytrastrea silberlingi and K. cuifiamorpha, Flexastrea serialis, Nevadoseris punctata, Areaseris nevadaensis and a new genus Minasteria (with Astrocoenia shastensis Smith, 1927 as type species). Likewise are the new species: Margarogyra silberlingi and Curtoseris dunlapcanyonae. Genera Meandrovolzeia, Margarogyra, Ceriostella, Ampakabastraea, Retiophyllia, Distichomeandra, Curtoseris, Thamnasteria and Astraeomorpha provide important links to the former Tethys province. The revised coral fauna changes previous views of the close taxonomic similarity with the Tethys, instead producing a paleogeographic pattern emphasizing a much greater degree of endemism. This pattern emphasizes the isolation of Nevada from the Tethys and the similarities with some outboard terranes of the Cordillera.

Molluscan assemblages from upper middle Eocene deposits of southwestern Washington represent a regional biotic system that provides independent evidence of a range of depositional environments in a delta. Four marine molluscan assemblages reflect a subtropical fauna that inhabited an inner neritic to upper bathyal gradient down the prodelta slope. Comparisons with Recent molluscan taxa indicate changing trophic structures from dominantly infaunal filter feeding in the shallow, coarser-grained substrate to dominantly infaunal deposit feeding in the fine-grained mud. A very high diversity of carnivorous gastropods indicates that the biocenosis included a wide array of predominantly errant, soft-bodied invertebrate prey. The most shallow marine assemblages show evidence of dense Turritella patches within infaunal bivalve-dominated associations, indicating mosaics of distribution across a soft-sediment substrate. Low diversity marginal-marine and freshwater assemblages show faunal links with each other. They indicate interdistributary bay and marsh environments that are commonly part of a river-dominated delta.

One new species of retiolitid, Gothograptus storchi, five new species of monograptids (Monograptus patulus, Monograptus glutiformis, Streptograptus galeus, Testograptus cubitus, and Monoclimacis capillus), and one new cyrtograptid, Cyrtograptus palmatus, are described from the lower Homerian lundgreni Biozone of Arctic Canada. The presence of a species of Gothograptus in the Cyrtograptus lundgreni Biozone of Arctic Canada is documented for the first time. Further, full-relief specimens of Cyrtograptus multiramis Törnquist? and C.? urbaneki Teller are described. Better and more completely preserved, isolated material of Sokolovograptus cf. S. parens Obut and Zaslavskaya, Pseudoplectograptus sagenus, Cometograptus apsis, C. nevadensis, Monograptus biglossa, Cyrtograptus hamatus, C. lundgreni, and C. radians, previously described in Lenz and Kozłowska-Dawidziuk (2001a), is also illustrated. The total global species diversity of the lundgreni Biozone thus approaches 50, making the subsequent extinction event even more profound.