Three species of Karakaschiceras, K. attenuatus (Behrendsen, 1892), K. neumayri (Behrendsen, 1892), and K. lycoris (Leanza and Giovine, 1949), and one species of Neohoploceras, N. arnoldi (Pictet and Campiche, 1860), are described and figured from the Valanginian strata of the Neuquén basin in west-central Argentina. The large collection of fossils available for study shows wide intraspecific variation regarding ornament and whorl section in Karakaschiceras neumayri and Neohoploceras arnoldi, casting some doubts on the current systematics applied to species of these genera. The biostratigraphic position of the four species in the Neuquén basin corresponds to the Karakaschiceras attenuatus Subzone of the Olcostephanus atherstoni Zone. This subzone is correlated with the Mediterranean Karakaschiceras inostranzewi and Saynoceras verrucosum zones of Europe at the base of upper Valanginian sections.

A new genus of long-horned chasmosaurine ceratopsid is described from the Dinosaur Park Formation (upper Campanian) of Western Canada. Mojoceratops perifania is represented by a skull and a parietal from the Dinosaur Park Formation of Alberta and an isolated parietal from the Dinosaur Park Formation of Saskatchewan. Several other specimens are provisionally referred to this taxon. While Mojoceratops shares many plesiomorphies with Chasmosaurus, the animal lacks the forward-curving parietal epoccipitals and reduced postorbital horns that diagnose the genus Chasmosaurus, and it differs from all other chasmosaurines in exhibiting a prominent sulcus on the anterior margin of the parietal, swellings on the anterodorsal surface of the parietal rami, and a small accessory process on the first parietal epoccipital. Other unusual features include anteriorly extended parietal fenestrae, a broad, heart-shaped frill, and transverse expansion of the postfrontal fontanelle. The type material of “Eoceratops canadensis” and “Chasmosaurus kaiseni” are nondiagnostic and these names are therefore considered nomina dubia, but their morphology is consistent with Mojoceratops and they probably belong to this genus. The frill of Mojoceratops shows marked variation. Some of this variation probably results from intraspecific variation or ontogenetic changes, but because the Dinosaur Park Formation encompasses more than a million years of time, evolution may explain some of these differences. Phylogenetic analysis shows that Mojoceratops forms a clade with Agujaceratops mariscalensis; Chasmosaurus is the most basal member of Chasmosaurinae.

Since 1986, samples with a total mass of more than 14,000 kg, mainly from three key sections in western Hunan, South China, have been processed for conodonts. Previous work mainly focused on biostratigraphy, but the taxonomy has been performed only on the faunas of the middle Cambrian. Described herein are conodonts of the upper Cambrian (Furongian Series) through lowermost Ordovician from Hunan, South China. Conodonts of the middle Cambrian are redescribed, based on material that has been recovered for more than three decades. The fauna consists of 82 species belonging to 36 genera. Newly established genera are Lugnathus n. gen., Miaognathus n. gen., Millerodontus n. gen., Tujiagnathus n. gen., Wangcunella n. gen. and Wangcunognathus n. gen. New species are Coelocerodontus hunanensis n. sp., Furnishina wangcunensis n. sp., Laiwugnathus hunanensis n. sp., Laiwugnathus transitans n. sp., Lugnathus hunanensis n. gen. n. sp., Miaognathus multicostatus n. gen. n. sp., Millerodontus intermedius n. gen. n. sp., Prosagittodontus compressus n. sp., Tujiagnathus gracilis n. gen. n. sp., Wangcunella conicus n. gen. n. sp., Wangcunognathus elegans n. gen. n. sp., Westergaardodina dimorpha n. sp., Westergaardodina gigantea n. sp., and Westergaardodina sola n. sp. The taxonomy of some conodont genera is revised. In the light of histological investigation, genera are assigned to euconodonts, paraconodonts, or protoconodonts. The 13 conodont zones previously proposed in the middle Cambrian through lowermost Ordovician remain the same, but taxa within these conodont zones are documented more clearly because of the revised taxonomy proposed herein.

Cambrian strata of the Laurentian craton contain numerous examples of Burgess Shale–type faunas. Although displaying a more or less concentric distribution around the cratonal margin, most faunal occurrences are in present-day western North America, extending from the Northwest Territories to California. Nevertheless, the soft-bodied and lightly skeletalized fossils in most of these Lagerstätten are highly sporadic. Here, we extend knowledge of such Middle Cambrian occurrences in Utah with reports of four taxa. An arthropod from the Marjum Formation, Dytikosicula desmatae gen. et sp. nov., is a putative megacheiran. It is most similar to Dicranocaris guntherorum, best known from the younger Wheeler Formation, but differs primarily in the arrangement of pleurae and overall size. Along with a specimen of ?Yohoia sp, a new species of Yohoia, Y. utahana sp. nov., is described. It differs from the type and only known species, Y. tenuis, principally in its larger size and shorter exopods; it is the first description of this genus from outside the Burgess Shale. A new species of a stem-group lophotrochozoan from the Spence Shale, Wiwaxia herka sp. nov., possesses a palisade of dorso-lateral spines that are more robust and numerous than the type species of Wiwaxia, W. corrugata. Another notable taxon is Eldonia ludwigi from the Marjum Formation, which is interpreted as a primitive ambulacrarian (assigned to the cambroernids) and a new specimen of the ?cnidarian Cambrorhytium from the Wheeler Shale is illustrated.

The Mazon Creek Cycloidea contain four taxa: Cyclus americanus Packard, 1885, Cyclus obesus, new species, Halicyne max, new species, and Apionicon apioides, new genus, new species. We conclude, based on a cladistic analysis, that cycloids are specialized maxillopodan crustaceans and a possible sister group to the Copepoda. They may have filled a niche similar to modernday crabs.

Ophioxenikos langenheimi n. gen. and sp. (class Somasteroidea), Stibaraster ratcliffei n. gen. and sp., and Cnemidactis? macroadambulacralatus n. sp. (both class Asteroidea) are new stelleroid echinoderms described from Lower and Middle Ordovician strata of the western United States. Stibaraster clearly is at the asteroid grade of organization, although an early representative of the class. Ophioxenikos is the first fossil somasteroid recognized from beyond Europe. It is similar to Chinianaster and Villebrunaster, ambulacral characters of all three suggest affinities with ophiuroids. Cnemidactis? is recognized from North America; it is unusual in the presence of proportionately large marginal ossicles. An indeterminate species is unusual in its structural parallels with living taxa. In recent years, the possibility that edrioasteroids were ancestral to stelleroids has been revived. Supporting arguments for this hypothesis neglect important differences; ancestry of stelleroids remains uncertain.

A new genus and three new species of the microchiropteran family Mystacinidae are described from Miocene freshwater limestones in northern Australia. The type species, Icarops breviceps new genus and species, is from the middle Miocene Bullock Creek deposit, Northern Territory; I. aenae new species and I. paradox new species are from the slightly older (early Miocene) Wayne's Wok and Neville's Garden Sites at Riversleigh, northwestern Queensland. Fossil mystacinids are rare in each deposit and represented so far only by lower teeth and dentary fragments. They are characterized by a suite of apomorphies shared only with Quaternary mystacinids endemic to New Zealand. The family Mystacinidae has no pre-Pleistocene record and its relationships to other groups of bats remain unclear. Possible sister-groups include South American noctilionoids and the cosmopolitan molossoids and/or vespertilionoids. The presence of plesiomorphic mystacinids in the Australian Tertiary suggests an Australian origin for the family.

The uppermost 5–15 m of the Douling Formation in the southern Hunan area, South China, yields a diverse fauna comprised of ammonoids, bivalves, and brachiopods. The brachiopods reported in this paper consist of 51 species in 34 genera and are dominated by the Lopingian (Late Permian) species associated with a few species persisting from the underlying Maokouan (Late Guadalupian). This fauna is of earliest Wuchiapingian in age as precisely constrained by the associated conodont Clarkina postbitteri postbitteri and the Guadalupian-type ammonoid fauna of the Roadoceras-Doulingoceras Zone in the brachiopod horizon. The discovery of the Lopingian species-dominated brachiopod fauna in the earliest Wuchiapingian in southern Hunan suggests a much less pronounced effect of the pre-Lopingian crisis (end-Guadalupian mass extinction) than the end-Changhsingian mass extinction in terms of brachiopods, a contemporaneous onset of the Lopingian recovery/radiation during the pre-Lopingian crisis period, and taxonomic selectivity of the pre-Lopingian crisis in terms of different fossil groups. New taxa are Echinauris doulingensis n. sp., Pararigbyella quadrilobata n. gen. and n. sp. and P. doulingensis n. gen. and n. sp.

The new asteroid species Sclerasterias zinsmeisteri (Asteriidae), Paragonaster clarkae, Tesselaster clarki (both Goniasteridae), and the new ophiuroid species Ophiura hendleri (Ophiuridae) are described from the late Eocene La Meseta Formation at Seymour Island, Antarctic Peninsula. The arm tip of an apparently new genus of the Oreasteridae is too incomplete to assign at the generic level. Other La Meseta asteroid species have been described elsewhere. Six of seven recognized stelleroid genera and all represented families survive, and differences between new species and existing congeneric species are subtle. Thus, the La Meseta fauna was similar to living faunas in basic composition.

Among La Meseta asteroids, Zoroaster aff. Z. fulgens and Ctenophoraster downeyae are known from numerous specimens; fossils of the other species are comparatively uncommon and given the uncertainties of sampling, further taxa might await discovery at Seymour Island. Although the Paxillosida is known from Jurassic rocks, fasciole-bearing, semi-infaunal genera are first known from Cretaceous deposits, and Astropecten and Astropecten-like Ctenophoraster are first recorded from Cenozoic rocks. Zoroaster and Tesselaster are only known from deep water settings today, although they are found in the La Meseta. Ophiura hendleri, the only ophiuroid recognized to date from the La Meseta, occurs singly, in small groups, and in Paleozoic-type ophiuroid-rich beds.

The stromboid fauna from Cenozoic deposits of Chile contains an unusual mixture of warm-water and cool-water taxa, showing relationships with either Argentinian or New Zealand taxa. Six species of Strombidae, Aporrhaidae, and Struthiolariidae are described, and their relationships and paleobiogeographic implications are discussed. Conus medinae Philippi, 1887 from the Miocene Navidad Formation is assigned to the genus Strombus and thereby constitutes the first record of Strombidae from southwestern South America. The new subgenus Austrombus is proposed for smooth species of Strombus without any spines or axial sculpture. Hemichenopus araucanus (Philippi, 1887) from the ?Eocene of Peninsula Arauco shows strong affinities to Dicroloma zelandica Marshall, 1919 from the Eocene of New Zealand, which is here assigned to Hemichenopus. The New Zealand species Perissoptera (Hemichenopus) thomsoni Allan, 1926 does not belong in Hemichenopus but could not be reassigned to another aporrhaid genus. Struthiochenopus bandeli n. sp. and Struthiochenopus philippii Zinsmeister and Griffin, 1995 are reported from deepwater facies in Chile, rather than the nearshore facies favored by congeners in Argentina. Perissodonta ameghinoi (Ihering, 1897) and Perissodonta chilensis (Philippi, 1887) are the only species of this genus in the eastern Pacific, the former being an Atlantic species, reported for the first time from the Pacific. The term Neo-Weddellian is proposed for Miocene taxa having their origin in the Late Cretaceous–Paleogene Weddellian Province.

The whip scorpions (Arachnida: Uropygi) from the Pennsylvanian Coal Measures of Mazon Creek, Illinois, USA are restudied. Four Mazon Creek uropygid specimens have previously been described and a fifth is added here. Contrary to earlier reports, none of the specimens lack eyes and the sternum is similarly shaped in all the specimens. Consequently, the two younger names, Geralinura similis Petrunkevitch, 1913 and G. gigantea Petrunkevitch, 1913 are here treated as junior synonyms of G. carbonaria Scudder, 1884. The morphology of the pedipalps is more like those of some modern amblypygids, being spiniferous and non-chelate, suggesting the subchelate palps found in all Recent whip scorpions is an apomorphy not yet incorporated into the bodyplan of G. carbonaria. Indeed, subchelate palps also seem to be absent in other species of this age. For completeness, we summarise here the six Pennsylvanian whip scorpions currently recognised—including sketch reconstructions—with comments on further differences between the Paleozoic and living taxa. Geralinura Scudder, 1884 is reserved for G. carbonaria and the British species G. britannica Pocock, 1911. Prothelyphonus Friĉ, 1904 is reinstated for the Czech species P. bohemicus (Kuŝta, 1884). Parageralinura gen. nov. is proposed for the widely overlooked Dutch species P. neerlandica (Laurentiaux-Vieria and Laurentiaux, 1961) and the German species P. naufraga (Brauckmann and Koch, 1983). All the Coal Measures whip scorpion genera are treated here as plesion taxa, basal to the Thelyphonidae, which can be defined as whip scorpions with a fully subchelate pedipalp, the chelae formed from large and distinct patellar and tibial apophyses.

Scanning electron microscopy of the architecture of Rotalina inermis Terquem, 1882, the type-species of the genus Pararotalia Le Calvez, 1949, and of Rotalia mexicana Nuttall, 1928, the type-species of the genus Neorotalia Bermudez, 1952, reveals that both taxa have in common: 1) an umbilical bowl closed by either a single or a compound umbilical plug; 2) an interiomarginal extraumbilical aperture, restricted by a toothplate that protrudes with a free edge into the aperture and forms an umbilical spiral canal; and 3) a septal flap and intraseptal interlocular spaces. Rotalia mexicana, however, also possesses an enveloping canal-system, similar to that found in the Calcarinidae. For this reason Neorotalia must be regarded as a valid distinct genus, not synonymous with Pararotalia, as proposed by some authors. Calcarina calcar d'Orbigny, 1839, variously placed by authors in Rotalia Lamarck, 1804, in Pararotalia Le Calvez, 1949, and lately again in Calcarina d'Orbigny, 1826, is shown to possess the same basic architecture as Neorotalia and is placed, consequently, into this latter genus. Irregular supplementary apertures occurring in N. calcar are not considered of generic value and neither are they regarded as indicating a relationship with Nautilus spengleri Gmelin, 1788, the type-species of Calcarina. The latter, although characterized by a complex enveloping canal-system, possesses primary multiple interioareal main apertures, surrounded by thick rims, as well as a small umbilical plate, but lacks a toothplate with a free edge. For comparison, Pararotalia spinigera (Le Calvez, 1949) and Neorotalia viennoti (Greig, 1935) were also studied. The subfamily Pararotaliinae Reiss, 1963, is emended to include the canal-system as a characteristic feature. A glossary of selected terms is appended.

The skeleton of a newly discovered, exceptionally preserved specimen of Saniwa ensidens is described in detail. the fossil consists of a complete articulated skeleton exposed in dorsal view. It adds important additional information to our knowledge of the anatomy of this fossil varanoid taxon, including a detailed description of the dermatocranium in dorsal view, complete vertebral counts, and a detailed account of the appendicular skeleton. Cartilage preservation allows the identification of treacheal rings, sternum, inscriptional ribs, epicoracoid and suprascapula. Patches of skin are preserved on dermal skull bones, and scattered scales surround the entire skeleton. Incomplete ossification of carpal and tarsal elements, as well as of epiphyses, indicate that the specimen is not fully mature.

To investigate the phylogenetic affinity of Yuknessia simplex Walcott, 1919, scanning electron microscopy was applied to the Burgess Shale (Cambrian Series 3, Stage 5) type material and to new material from the Trilobite Beds (Yoho National Park) and specimens from the Cambrian of Utah. On the basis of fine-scale details observed using this approach, including banding structure interpreted as fusellae, Yuknessia Walcott, 1919 is transferred from the algae, where it resided for nearly a century, to the extant taxon Pterobranchia (Phylum Hemichordata). Considered as such, Yuknessia specimens from the Trilobite Beds and Spence Formation (Utah) are amongst the oldest known colonial pterobranchs. Two morphs regarded herein as two different species are recognized from the Trilobite Beds based on tubarium morphology. Yuknessia simplex has slender erect tubes whereas Yuknessia stephenensis n. sp., which is also known in Utah, has more robust erect tubes. The two paratypes of Y. simplex designated by Walcott (1919) are formally removed from Yuknessia and are reinterpreted respectively as an indeterminate alga and Dalyia racemata Walcott, 1919, a putative red alga.

A new juvenile specimen of Pteranodon from the Smoky Hill Chalk Member of the Niobrara Formation of western Kansas had an estimated wingspan in life of 1.76 m, ~45% smaller than the smallest previously known specimens, but does not differ in morphology from larger specimens. Its presence indicates that juveniles were capable of flying long distances, so it falsifies the interpretation of Pteranodon as growing rapidly to adult size under parental care before flying. Instead juveniles were precocial, growing more slowly to adult size while flying and feeding independently for several years before going to sea. Because juveniles are otherwise unknown in the Smoky Hill Chalk Member, they must have occupied different environments and ecological niches than adults; thus Pteranodon exhibited ontogenetic niches. Evidence is presented that most other pterosaurs (e.g., Rhamphorhynchus, Pterodactylus, Anhanguera) also exhibited various ontogenetic niches, which, along with their large body size, suggests that pterosaur taxonomic diversity was rather low, like that of crocodilians.

Protichnites eremita from the Cambrian Elk Mound Group of Wisconsin is reinterpreted based on new material and trackway experiments. Two new forms of P. eremita suggest that the discrete medial imprints of these traces could be produced by the segmented postabdomen of euthycarcinoids from the same deposit. Form 1 could have been produced by a pair of euthycarcinoids traveling together, like in limulid amplexus, where both individuals made imprints with their postabdomens. In this scenario, if one individual held its postabdomen to the left side, it is possible to produce left-handed shingling in trackways and angled segmentation of each medial imprint. Form 2 could have been produced by a single animal traveling in arcing or tightly looping paths. Experimentally-produced medial imprints yield morphologies that are consistent with both trackway forms. Thus, it seems more likely that P. eremita was produced directly by the animal's body (alone or paired) rather than by employing hermit-like behavior.

An abundant, varied, and well-preserved assemblage of discrete sponge spicules of late Ordovician age is described from the Malongulli Formation of central New South Wales. It is associated with one of the most diverse Ordovician siliceous sponge faunas known. The assemblage occurs in allochthonous limestone blocks within breccia deposits of a predominantly graptolitic and spiculitic siltstone succession, and is composed mainly of hexactinellid spicule types. Included are a number of distinctive forms, recognized as new taxa—Silicunculus bengtsoni, Kometia cruciformis, Chelispongia prima, and Pseudolancicula exigua. All are new genera except Silicunculus Bengtson, 1986, which was previously described from the upper Cambrian of Queensland. The problematical Anomaloides reticulatus Ulrich, 1878, is reported for the first time from Australia. A wide variety of other diagnostic, but more generalized, spicule types also occurs, including stauractines, pinnular and nonpinnular pentactines and hexactines, ornamented oxyhexasters and echinhexasters, clavules, anchorate root-tufts, and uncinates. The pinnular pentactines may be assigned to the form genus Palaeorubus Ishiga (in Ishiga et al., 1987), interpreted incorrectly by Ishiga as a radiolarian. The sponges, discrete spicules, and radiolarians of these limestone clasts were transported in debris flows to a basinal setting from peri-platform oozes that formed on the flanks of the shallow offshore island-arc platform of the Molong High.

The earliest known record of lingulid-coral associations is described from Ashgill tabulate corals preserved on Manitoulin Island, Ontario. Lingulid infestation of tabulate corals and stromatoporoids also is locally abundant in Ashgill and Llandovery limestones on Anticosti Island, Québec, and these preserve the new lingulid species Rowellella? anticostiensis inside the cavities of Trypanites borings. In all examples, lingulids appear to nestle in previously formed Trypanites, likely in a dead host coral or stromatoporoid. In some instances in the Silurian of Anticosti, regeneration of host growth while infested by lingulids is evidenced by a new type of compound trace fossil, Klemmatoica linguliforma new ichnogenus and ichnospecies. Similar endosymbiotic relationships previously observed in Silurian corals from Wales and Sweden suggest that the lingulid association with tabulate corals and stromatoporoids was widespread in early Paleozoic shallow marine settings.

Recurring associations of the trilobite ichnogenus Rusophycus with various “worm” burrows suggest an interaction between the two tracemakers, specifically, capture of the worm by the trilobite. An exceptional ichnofossil from the Upper Ordovician of southwestern Ohio shows characters consistent with previously described “trilobite hunting burrows” from Cambrian and Silurian strata. Preserved in convex hyporelief is R. carleyi, attributable to the trilobite Isotelus, on which is superimposed the case of a worm burrow of the ichnogenus Palaeophycus. The cast of the worm burrow appears to have been truncated by the digging activities of the trilobite, suggesting its predation of the worm. The exquisite preservation of ventral axial morphology of the trilobite distinguishes this Rusophycus from simpler bilobate forms attributable to filter-feeding behavior. Congruency in the preservation of worm and trilobite trace supports the conclusion that both were created at the same time, as the trilobite exited the intrastratal burrow. This is the first report of a trilobite hunting burrow from the Ordovician, and the first evidence for predatory behavior for the trilobite genus Isotelus.