Three new and one completely preserved species of hexactinellid sponges are described from Early Cambrian black shales of South Anhui, China. The sponges occur in the middle part of the Huangboling Formation, which is assigned to the early Canglangpuian based on trilobite biostratigraphy. Metaxyspongia skelidata n. gen. and sp. and Hexatractiella dongzhiensis n. sp. are subcylindrical thin-walled Protospongiidae. Ratcliffespongia multiforamina n. sp. is assigned to the Hintzespongiidae. With these new sponges, the first occurrences of the Protospongiidae and Hintzespongiidae, and of Hexatractiella Mehl, 1996, can be traced back to the Early Cambrian. Solactiniella cf. plumata Steiner et al., 1993, with irregular rossellimorph skeletal architecture and regular spicular organization, is found here associated with the above species. Thus, the Anhui assemblage can be considered as intermediate between Atdabanian shallow-water communities of hexactinellids with irregular skeletons and the Middle Cambrian deepwater sponge facies characterized by regularly organized Hexactinellida.

An early late Emsian codiacrinid and Frasnian specimens of an indeterminate species of Parapisocrinus, an undesignated new genus of a catillocrinid, and two amabilicrinids are described from the eastern part of the Anti-Atlas Mountains of Morocco. These are the first articulated crinoid specimens reported from the Famennian of Morocco. Specimens occur within ammonoid-rich dysoxic shales, marls, and thin limestones at Ouidane Chebbi, Jebel Mrakib, Lambidia, and Rich Bou Kourazia. Parapisocrinus, the codiacrinid, and the catillocrinid are loose cups that are associated with other megafossils and may have been transported within the pelagic depositional settings. The amabilicrinids occur in three small unitaxial lenses, two of which have associated logs. The problems with and possibility of a pseudoplanktic lifestyle for stemmed crinoids are discussed.

These new collections expand the known stratigraphic and geographic distribution of the pisocrinid and amabilicrinids and the early evolutionary history of the catillocrinids. New taxa introduced are the amabilicrinids Mrakibocrinus bockwinkeli, Moroccocrinus ebbighauseni, and the codiacrinid Elicrinus? weyeri.

Echinoids are among the most conspicuous and diverse constituents of the Upper Cretaceous and Paleocene marine invertebrate fauna of Argentina. Nine species were collected from localities exposing the Jagüel (Maastrichtian), Roca (Maastrichtian– Danian), Salamanca (Danian), Arroyo Barbudo (Danian), El Fuerte (Danian), and Arroyo Salado (Danian) Formations in northern Patagonia, Argentina. Only one of these taxa, Paraster joannisboehmi (Oppenheim in Böhm, 1903), has been described previously from Argentina. Four taxa, Gauthieria menuthiae (Lambert and Savin in Lambert and Thiéry, 1911), Nucleopygus pullatus (Stoliczka, 1873), Diplodetus nutrix (Lambert in Boule, 1899), and Hemiaster hawkinsi Lambert, 1933, have been described previously from Madagascar. One species, Micropsis desori (Cotteau in Leymerie and Cotteau, 1856), has been described previously from France. One taxon, Pygopistes parrasae is a new species. Argentinian cassiduloids include the only two known Danian species of Nucleopygus and Pygopistes. The spatangoids were not strongly affected by the K-T extinction event. Comparisons of the Patagonian echinoids with those of the Northern Hemisphere indicate that they were strongly influenced by dispersal from Tethyan sources.

Reconsideration of the nature of zooids in trepostomate Bryozoa defines them as physically connected and asexually replicated colony members that housed systems of organs necessary to perform vital functions for the colonies. Zooids known to contain organs in trepostomes are limited to autozooids, the requisite feeding and sexual units, and polymorphs, including macrozooids and two rare zooids of unknown function. Other colony structures are extrazooidal and remain outside zooidal boundaries throughout colony life. They include the commonly occurring mesopores, exilapores, and styles. This two-part morphologic division of colonies reveals two correlated functions. The essential autozooids dominated the growth patterns and physiology of trepostome colonies; the extrazooidal parts grew concurrently and passively to connect autozooids and to support and strengthen colonies.

Pleurojulid millipedes, known since the turn of the last century to be relatively abundant in the Westphalian D (Carboniferous: Pennsylvanian) Gaskohl of Nýřany, Czech Republic, are here also identified as an important component of the Pennsylvanian (Westphalian D) Mazon Creek millipede fauna preserved in ironstone nodules. Pleurojulids reach lengths approaching 10 cm, have as many as 69 body segments, medium-sized heads, and large ocellaria with upwards of 40 ocelli. Pleurojulids have previously been interpreted as having either a juliform-like or a colobognathan-like trunk-ring architecture. In order to distinguish between these two hypotheses, almost all pleurojulid specimens in museum collections were surveyed to document the deformation pattern of exoskeletal elements to aid in reconstruction of the trunk-ring architecture. The Nýřany specimens are completely flattened while the Mazon Creek specimens retain a degree of three-dimensionality. In order to assess how trunk-ring architecture controls patterns of deformation, a variety of extant millipedes were experimentally compressed. The distribution of exoskeletal elements in pleurojulid fossils was most similar to that seen in compressed extant polyzoniid millipedes. Based on the available evidence, pleurojulid trunk-ring architecture is reconstructed as semicircular in cross section, consisting of arched diplotergites, free pleurites firmly articulated to the lateral margins of the tergites and held in a near horizontal position, and free sternites. Pleurojulida are hypothesized to be basal helminthomorph, the sister group to Colobognatha, though inclusion in Helminthomorpha is equivocal. The taxonomy of previously described pleurojulid millipedes from Nýřany is revised and newly recognized specimens from Mazon Creek specimens are described. Two genera are recognized within the new order Pleurojulida: Pleurojulus and Isojulus. Two species of Pleurojulus are recognized: P. biornatus and P. levis. Pleurojulus aculeatus and P. pinguis are synonymized with P. levis. Only one species of Isojulus, I. constans, is recognized with I. setipes, I. marginatus synonymized with it along with Pleurojulus longipes and P. falcifer.

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.

Two lineages exist for Cahabagnathus. Lineage 1 is C. friendsvillensis–C. chazyensis–C. sweeti–C. carnesi. Three new species are proposed in lineage 2, which consists of C. baueri n. sp.–C. directus–C. cooperi n. sp. and C. craigi n. sp. The distribution pattern of Cahabagnathus was strongly influenced by Chazyan sea-level changes. The wide distributions of C. friendsvillensis and C. sweeti correspond to two large transgressions and the more narrow distribution of C. chazyensis and C. carnesi correspond to regression events. A similar relationship exists between sea-level change and the distribution of species in lineage 2. Evolution of the cahabagnathids was apparently influenced by the rise of sea level, which widely distributed taxa, and the fall of sea level, which isolated taxa. We propose that it was from peripheral isolates of widely distributed taxa that endemic Cahabagnathus taxa (C. baueri, C. cooperi, C. craigi, C. chazyensis, and C. carnesi) evolved.

Restudy of two Early Silurian (Aeronian) stricklandioid species, Stricklandinia transversa Grabau, 1925 and Stricklandiella robusta Rong and Yang, 1981 from the Yichang area of South China, leads to the recognition of two new genera, Sinokulumbella and Sinostricklandiella. Two types of spondylia and four types of cardinalia are recognized for the Stricklandioidea and can be used for classification of the superfamily at the generic or even familial level. On the basis of these characters, five groups (typified by Stricklandia, Stricklandiella, Kulumbella, Microcardinalia, and Aenigmastrophia) can be recognized within the superfamily. Sinokulumbella n. gen., with a small, shallow, bowl-shaped spondylium and a pair of outer hinge plates that are discrete from the crura, is regarded to be affiliated with the Kulumbella group. Sinostricklandiella n. gen. has superimposed plicae and costae, although its internal structures are similar to the Stricklandiella group. A revised classification of stricklandioids implies that the Chinese pentamerides were characterized by strong provincialism during the early and middle Llandovery. This interpretation is supported further by the complete lack of true Stricklandia and Microcardinalia lineages in South China. Different stocks of stricklandioids in Baltica, Laurentia, South China, Siberia, and Kazakhstan may have experienced allopatric evolution, punctuated by several pulses of faunal migration or exchange between these paleoplates during the Llandovery. Evolution of the Stricklandia lineage is significantly different from that of Kulumbella and Sinokulumbella, particularly in that the outer plates disappeared earlier in the kulumbellids than in the stricklandiids.

Isolated marginal tooth crowns of the early Campanian mosasaur Hainosaurus Dollo, 1885, from the Kristianstad Basin and the Vomb Trough, southern Sweden, are described and illustrated. The teeth have been collected from a narrow stratigraphic interval corresponding to the highest belemnite zone in the lower part of the European two-fold division of the Campanian stage. A reexamination of dental and skeletal characters in two alleged species of Hainosaurus, ‘H.’ pembinensis Nicholls, 1988 and ‘H.’ gaudryi (Thévenin, 1896), and detailed comparisons with the corresponding elements in H. bernardi Dollo, 1885 and Tylosaurus proriger (Cope, 1869a), strongly indicate that ‘H.’ pembinensis and ‘H.’ gaudryi are both Tylosaurus Marsh, 1872. Diagnostic features of Hainosaurus include a very small infrastapedial process on the quadrate (conspicuous protuberance in Tylosaurus), flattened, symmetrically bicarinate marginal teeth (asymmetric and conical in Tylosaurus), short and wide pygal centra, and anteriorly situated intermediate caudal vertebral centra with dorsoventrally thin transverse processes (markedly triangular centra and thick processes in Tylosaurus).

A new genus and species of eurypterid (Eurypterida: Chelicerata) is described as Orcanopterus manitoulinensis from the Upper Ordovician Kagawong Submember (Upper Member) of the Georgian Bay Formation, Manitoulin Island, Ontario, Canada. The material comprises several partial specimens in addition to disarticulated carapaces, appendages, metastomas, opisthosomal segments, and telsons. Associated fossils include rare bryozoans, a conularid, ostracodes, and conodonts. A restricted marine lagoon, or very shallow subtidal to intertidal environment is inferred. This assemblage, perhaps representing an accumulation of molted exuviae, was apparently preserved as the result of rapid burial by carbonate muds and silts during a storm event. O. manitoulinensis shares a number of traits with both the Hughmilleriidae and the Carcinosomatidae. Diagnostic features include curved preabdominal segments, a petaloid A metastoma with deep anterior emargination, spiniferous appendages of Carcinosoma type, paddle with enlarged, symmetrical podomere 9, and a xiphous telson. It is only the fourth (the first Canadian) well-documented Ordovician eurypterid genus, and provides the oldest reliable record of the Hughmillerioidea to date.

Representatives of several genera of late Paleozoic Caenogastropoda have been studied based on exceptionally well-preserved material from the latest Permian of south China, the Pennsylvanian of the United States, and the Early Carboniferous of Australia. This material has well-preserved protoconchs which are relatively rare in Paleozoic gastropods. The morphology of the protoconch and especially that of planktotrophic larval shells gives crucial taxonomic and phylogenetic information. It helps to recognize convergence, which is common in Gastropoda. The larval shell morphology of the following taxa is discussed and illustrated: Platyzona (Goniasmatidae), Erwinispira n. gen. (Erwinispirinae n. subfam.), Propupaspira (Propupaspiridae), Soleniscus (Soleniscidae), Meekospiridae, and Chlorozyga (Imoglobidae). The new species Meekospira? solenisiciforma is described. The main diagnostic feature of the order Procaenogastropoda, a fluent protoconch/teleoconch transition, probably represents a preservational artifact. An abrupt transition indicating metamorphosis can be shown for several genera which have been assigned to the Procaenogastropoda. Therefore, the monophyly of the Procaenogastropoda is questioned, and the taxon is refuted. While the caenogastropods of latest Permian gastropod faunas are dominated by typical late Paleozoic genera and families, the Early Triassic is characterized by an almost complete faunal turnover of caenogastropod genera.

Neoplagiaulacid multituberculates are among the most numerous and best represented members of early Cenozoic North American mammal faunas, achieving their greatest diversity during the Paleocene. Despite their relatively dense record in the Torrejonian (middle Paleocene) and Tiffanian (late Paleocene), the study of early Cenozoic neoplagiaulacids has been limited more often than not to isolated teeth or, more rarely, incomplete skull, gnathic, or postcranial remains. The current study reports on new neoplagiaulacid multituberculates from the Paleocene Paskapoo Formation of central Alberta, Canada, at localities along the Blindman River near the City of Red Deer. The exceptionally well-preserved specimens consist of incomplete articulated and associated skull and gnathic remains, and collectively document four new species: Ectypodus elaphus, Neoplagiaulax serrator, Neoplagiaulax paskapooensis, and Neoplagiaulax cimolodontoides. Neoplagiaulax paskapooensis is the most dentally complete neoplagiaulacid so far discovered, with a single specimen documenting for the first time left and right I2 and I3 in situ with the cheek teeth, along with the associated lower dentition. Specimens of Neoplagiaulax cimolodontoides record important details of the rostrum and palate, and provide the first direct evidence of incisor replacement in Neoplagiaulax. The new neoplagiaulacids, together with other multituberculates from the Blindman River localities, document unusually high multituberculate diversity in the latter half of the Tiffanian in western Canada. Despite superficial similarity to some European species of Neoplagiaulax, the new taxa from the Paskapoo Formation apparently show no closer relationship to these than do other North American congeners, suggesting parallel evolution in endemic North America and western European clades.