A detailed taxonomical description of scleractinian corals from the Maastrichtian of Mexico (Cardenas Formation) is given for the first time. The coral association comprises 16 taxa which belong to 9 families: Dictuophyllia conferticostata (Vaughan), Cladocora jamaicaensis Vaughan, Cladocora gracilis (d'Orbigny), Antiguastrea cellulosa (Duncan), Multicolumnastraea cyathiformis (Duncan), Placocoenia major Felix, Siderastrea vancouverensis Vaughan, Siderastrea adkinsi (Wells), Goniopora sp., Actinacis haueri Reuss, Actinacis parvistella Oppenheim, Actinhelia elegans (Goldfuss), Meandrophyllia oceani (de Fromentel), Dermosmiliopsis orbignyi Alloiteau, Trochoseris aperta Duncan, and Cyathoseris formosa d'Achiardi. The corals described herein were collected from mixed coral-rudist and coral-dominated assemblages in the Arroyo de la Atarjea, and one unnamed riverbed which lithologically correspond to the Arroyo de la Atarjea section, both of which belong to the upper member of the Cardenas Formation. On the genus level, 94% of the Mexican fauna corresponds to the Maastrichtian coral assemblages of Jamaica. Moreover, the Cardenas fauna shows close affinities to both Upper Cretaceous coral associations of central Europe and the Caribbean, as well as to Lower Tertiary faunas of Central America and the Caribbean. On the species level, 68.8% of the Cardenas corals are known from Lower Tertiary strata of Central America, the Caribbean, South America, Asia, European/Mediterranean region, and/or southeastern parts of the USA.

The morphologic expression of microenvironmental variation is difficult to document in fossil ecosystems and therefore is poorly understood. However, documentation of environmental sources of variation in the phenotype is essential for meaningful studies of microevolution and speciation. A fossil assemblage from the Mississippian (Valmeyeran) Warsaw Formation near St. Louis, Missouri, provides necessary conditions to evaluate microenvironmentally induced phenotypic variation in the Paleozoic trepostome bryozoan Leioclema punctatum (Hall, 1858). Specimens of L. punctatum, found as fragments in 22 discrete piles, were collected in their entirety from a weathered surface. Each pile contained 20–200 branch fragments of L. punctatum, which were all originally attached to large, soft-bodied hosts (sponges?). Multiple attachment bases were found in most piles, indicating that 1) multiple L. punctatum colonies (genotypes) are represented in each pile, and 2) each pile represents a near contemporaneous, relatively short-lived microcommunity. Morphological characters were measured (four per section) from two branches for each of two specimens from five separate piles. Results from completely random, nested, one-way ANOVA indicate that no highly significant differences exist among microcommunities or between colonies for any measured characters, but that significant variation exists within colonies and among colonies in the same microcommunity (pile). That is, submicroenvironmental variation, within and among colonies, can play a greater role in morphogenesis than environmental heterogeneity within a given environmental setting (undifferentiated facies). Microenvironmental factors affect the size and shape of mesopores (space-filling structures) more than other morphological characters.

Results are encouraging for the general application of the preserved fossil phenotypes as proxies for biological species. This conclusion is based on the absence of systematic variation at microenvironmental levels, measurable here, but not normally distinguishable in paleontological and sedimentological studies. Correct attribution of fossil species assumes, however, that the source and the relative importance of the low-level (submicroenvironmental) variation on development/ontogeny is recognized and attributed appropriately. Results call for a reevaluation of the application of within versus among colony variation used as a proxy for environmental stability.

Long-stemmed eocrinoids are limited to two species in the basal Middle Cambrian Kaili Biota, which occupies the middle portion of the Kaili Formation, Taijiang County, Guizhou Province, China. The Kaili Biota contains preserved soft-bodied organisms shared with either the Chengjiang Fauna (Southwest China) or the Burgess Shale Fauna (British Columbia) or with both. Echinoderms are preserved as limonitic external molds that produce excellent latex casts. Sinoeocrinus lui Zhao et al., 1994 has a complex ontogenetic development, which is described in terms of morphology of holdfast, number of thecal plate circlets, addition and morphology of thecal pores, ambulacral arrangement, and number of brachioles relative to thecal height. Because of the complex ontogeny the following species are now seen to be synonymous with S. lui: S. curtobrachiolus Zhao et al.,1994; S. lepidus Zhao et al., 1994; S. longus Zhao et al., 1994; S. minus Zhao et al., 1994; Paragogia globosa Zhao et al., 1994; and Curtoeocrinus guizhouensis Zhao et al., 1994. A second and rare eocrinoid of undetermined familial and ordinal placement, Balangicystis rotundus n. gen. and sp., has an unusually long holdfast and poreless thecal plates with prominent radial ridges. Sinoeocrinus lui and Balangicystis rotundus inhabited the outer shelf in disaerobic fine-grained shales and mudstones. Megascopic infauna in their community is not present.

Abundant isolated elements of cornute and mitrate stylophorans were recovered from the upper Tremadocian Tumugol Formation in the Taebaeksan Basin, Korea. Cornute skeletal elements comprise a diverse assemblage of marginals and brachials of cothurnocystid affinities, suggesting the presence of no fewer than four different species. Mitrate remains include numerous isolated adorals, marginals, and aulacophoral plates with typical peltocystidan morphologies. Two adorals are identified as Anatifopsis sp., while all the others are attributable to A. cocaban. However, the two previously documented peltocystidans of Korea, A. cocaban and A. truncata, are sufficiently distinct from other Anatifopsis species to warrant assignment to a new genus, Taebaekocystis. Cladistic analyses suggest that Lagynocystida is the sister group of the clade uniting peltocystidans and mitrocystitidans and that the adorals of Taebaekocystis n. gen. and associated isolated peltocystidan elements possibly account for several different types of peltocystidans, intermediate in morphology between Peltocystidae and Kirkocystidae.

A diverse and well-preserved fauna of shelly fossils from the upper Lower Cambrian Bastion and Ella Island Formations of North-East Greenland contains more than 90 species. The fauna is the most diverse shelly fauna yet discovered in the Lower Cambrian of Laurentia and includes many fossils previously known only from other continental blocks. It enhances correlation of the North-East Greenland succession into Laurentia, most notably with the Browns Pond Formation of New York State, but also with other important Early Cambrian continents, in particular with Australia, Antarctica, and Siberia. A middle Dyeran age is most probable for both the Bastion and Ella Island Formation, and the rich fossil assemblage facilitates correlation with the Botoman Stage of Siberia and its equivalents. One new taxon is described, the disc-shaped problematicum Tunudiscus duovittarius n. gen. and sp.

A number of Early Cretaceous inoceramids are widely known worldwide, but many are poorly understood. In particular the nature of ligaments and muscle scars are in need of major revision. The inoceramid genus Neocomiceramus Pokhialainen and the species N. curacoensis (Weaver) are revised based on newly collected materials in the Neuquén Basin, west-central Argentina. Neocomiceramus curacoensis is recorded in the Agua de la Mula Member of the Agrio Formation. A Late Hauterivian age is indicated by the associated ammonite fauna. Neocomiceramus curacoensis has a shell shape similar to Inoceramus J. Sowerby, but its ligament lies in a higher angle to the commissural plane and has a smaller number of pits. Neocomiceramus curacoensis probably lived reclined and byssally attached on muddy offshore substrates under restricted oxygen levels. The genus Neocomiceramus ranges from the Valanginian?, Hauterivian to Albian and probably is cosmopolitan. It differs from other well-recognized Early Cretaceous inoceramid genera, namely Actinoceramus Meek, Anopaea Eichwald, and Coloniceramus Pokhialainen by its shell shape, shell thickness, ornamentation, and ligament morphology.

Dolostones of the upper Piauí Formation, Parnaíba Basin, northern Brazil, preserve a rich and diversified invertebrate fauna of Morrowan to Desmoinesian age. Among bivalves, Heteroconchia (15 species) is the most diversified, followed by Pteriomorphia (11 species), and rare endobenthic species of the Palaeotaxodonta (three species). Eleven species of Pteriomorphia are described, including representatives of the genera Parallelodon?, Myalina?, Septimyalina, Caneyella?, Leptodesma (Leptodesma), L. (Leiopteria), Meekopinna?, Aviculopinna?, and Aviculopecten. A new combination, Etheripecten trichotomus, and the oldest member of the Anomiidae recorded, Pindorama nordestina n. gen. and sp., also are described. Details of muscle scars and hinge characters have been recovered for several taxa, thereby refining the knowledge for species diagnoses. Fossil beds in the Esperança and Mucambo dolostones reveal episodic burial of bivalves in life position. These are internally complex, multistory fossil concentrations recording background and episodic processes. Hence, those fossil concentrations show high degrees of time-averaging and poor paleoecological resolution (except for the bivalves preserved in situ).

Upper Paleozoic Cephalopoda of west-central Patagonia are revised, based on reexamination of all available specimens and of most localities in Chubut Province, Argentina. Nautiloidea Orthocerida are represented by Sueroceras irregulare Riccardi and Sabattini, S.? chubutense (Closs), Sueroceras sp., and Mooreoceras zalazarense Sabattini and Riccardi and Pseudorthoceratidae gen. and sp. indeterminate; Nautilida by Amosiceras reticulatum new genus and species; and Ammonoidea Goniatitida by Glaphyrites taboadai new species and Glaphyrites sp. This fauna belongs to the Cisuralian Sueroceras irregulare and Mooreoceras zalazarense assemblage zones.

Trilobites previously assigned to the Entomaspididae Ulrich in Bridge, 1931 are common in Laurentian strata assigned to the upper Sunwaptan Stage of the Upper Cambrian. Most species are poorly known, and typically only sparse cranidial data are available. Large silicified samples from the Lava Dam Member of the Notch Peak Formation, western Utah, contain three new species for which cranidia, librigenae, thoracic segments, and pygidia are known. The species permit clarification of the morphology and affinities of previously described taxa from elsewhere. They are referred to Notchpeakia n. gen. (type species: N. milleri n. sp.) which, in addition to the type includes N. taylori n. sp., N. notchpeakensis n. sp., N. cherrycreekensis n. sp., and N. varga (Westrop, 1986). The “entomaspidid” trilobites are assigned to the traditionally post-Cambrian Harpetidae Hawle and Corda, 1847.

Upper Eocene and lower Oligocene deposits of the Jebel Qatrani Formation, Fayum Depression, Egypt, have provided a number of skulls and other bones that belong to a species of snakehead (Channidae). This material is morphologically more similar to species of Parachanna, rather than species of Channa, and is here described as a new species, Parachanna fayumensis. It differs from the other species of the genus in possessing a prominent tooth patch on the posterior end of the parasphenoid.

This new species of channid is the oldest member of the family known from Africa. Prior to this record, the oldest African fossil channid material was found in Mio–Pliocene deposits. This lack of information on the African fossil record leads to biogeographic reconstructions in which channids were believed to have arisen in Asia and invaded Africa through fresh waters, only after the two continents were connected in the Miocene. The Egyptian material shows that channids were in the fresh waters of Africa in the latest Eocene. Either a freshwater connection existed between Africa and Asia before or during the late Eocene, or members of the Channidae were able to migrate through marine waters to attain their current distribution.

Histology of newly discovered ganoid scales from the lower Bahariya Formation, in the Bahariya Oasis of western Egypt, confirms the presence of polypterid osteichthyans in this early Cenomanian locality. These fossils, occurring in the ∼97 million-year-old lower Bahariya sequences, are among the earliest known polypterids. The Bahariya scales exhibit four tissues: ganoin, dentine, isopedine (elasmodin), and a basal plate of cellular bone, confirming their inclusion within the Polypteriformes. They have a discontinuous ganoin layer, present only as highly variable ridges and bosses. Dentine along the edges of the ganoin ridges appears to have undergone active remodeling, suggesting that the ganoin ridges represent the remnants of a continuous ganoin cover. Modern polypterids inhabit exclusively freshwater environments. Polypterids are not rare in the lower Bahariya Formation. Their presence in these coastal sediments suggests that freshwater habitats lay close to the site of deposition of this sequence during the early Cenomanian.

A new actinopterygian, Cuneognathus gardineri new genus and species, is described from the Devonian (Famennian) Obrutschew Bjerg Formation of East Greenland on the basis of multiple incomplete specimens. Cuneognathus most closely resembles Limnomis from the Famennian Catskill Formation of Pennsylvania, and, like that taxon, is known exclusively from freshwater deposits. A cladistic analysis with an ingroup of 13 actinopterygians and an outgroup of five sarcopterygians explores the relationships between the new genus and some of its better-known Devonian contemporaries, and recovers the same four topologies regardless of the implementation of limited character ordering. Cheirolepis is resolved as the most basal of well-known Devonian actinopterygians, consistent with a majority of previous studies. A novel sister-group relationship between Howqualepis and Tegeolepis is found in all trees. Disagreement between the most parsimonious cladograms is concentrated in a clade whose members are often informally referred to as ‘stegotrachelids.’ Cuneognathus and Limnomis are resolved as sister taxa within this large radiation along with the pairings of Moythomasia dugaringa plus M. nitida and Krasnoyarichthys plus Stegotrachelus. The arrangement of taxa is conserved when the enigmatic Dialipina is added to the analysis, although the reconstructed position of that genus above both Cheirolepis and Osorioichthys seems improbable. Our scheme of relationships suggests that actinopterygians invaded freshwater environments at least four times during the Devonian, while age constraints indicate that many of the cladogenic events between ingroup taxa included in this study occurred during or before the Givetian.

Abundant and diverse trace fossils occur in deposits, recording an Early Devonian transgression in Bolivia. The very well-exposed Presto-El Peral section is located in the Interandean Belt 50 km northeast of Sucre. Trace fossils can be assigned to five associations from nearshore to offshore environments (namely Skolithos, Diplocraterion, Altichnus, Palaeophycus, and Zoophycos associations). They clearly illustrate the different colonization phases of the benthos with increasing marine influence. A deeper-water Helminthopsis association occurs in other complementary sections on the Eastern Cordillera. Variation of bioturbation intensity, ichnodiversity, and preservation potential is evaluated. The morphology of traces, mainly deep burrows, shows a significant gradient related to the behavior of tracemakers and the environmental changes. Main trends are consistent with the Seilacherian bathymetric model which is detailed here and/or emended with a well-exposed field example. A precise correlation is proposed with fossil benthic associations dominated by brachiopods. The whole gives an accurate model for benthos colonization and benthic marine zonation.