An abundant and well preserved trilobite fauna is described from Upper Cambrian calcareous mudstones of the McKay Group, near Cranbrook in southeastern British Columbia. The trilobites are mostly articulated, consisting of similar numbers of molts and carcasses. They are representative of a new deep water biofacies, the Wujiajiania Biofacies, and a new Wujiajiania sutherlandi Fauna of late Steptoean age. The trilobites were collected from a narrow interval (<20 m thick) of richly fossiliferous strata, in a thick sequence of unfossiliferous to sparsely fossiliferous strata of similar lithology. The fauna includes fourteen species, six of which are new: Aciculolenus palmeri, Burnetiella leechi, Hedinaspis canadensis, Labiostria westropi, Pterocephalia norfordi, and Wujiajiania sutherlandi.

Heliolitine corals occur in Upper Silurian strata of the topmost Douro, lower Barlow Inlet, and lower Somerset Island formations in the Boothia Uplift region. The fauna includes Heliolites (nine species), Propora (two species), the stelliporellid genera Podollites (three species) and Stelliporella (one species), and the plasmoporid Squameolites (one species). Species present but not previously reported from the region include Heliolites arcuatus Bondarenko, Heliolites uksunayensis Mironova, Stelliporella ilensis Bondarenko, Podollites assitus new species, Podollites parryi new species, Podollites plectilis new species, Propora tubulata (Lonsdale) and an unidentified species of Propora. All species occur in reef and reef-associated facies of open carbonate shelf and ramp settings. In restricted nonreefal carbonate shelf settings, diversity attenuates to a minimum, exemplified by numerically abundant monospecific assemblages of Heliolites uksunayensis. Six of the 16 morphotaxonomic units recognized compare with species reported previously in Silurian faunas of Kazakhstan and Mongolia. Combinations of characters in the species attributed to Podollites support revision of the genus, possibly to include Derivatolites and Tarbagatailites, in a group morphologically intermediate between Stelliporella and Heliolites.

Scanning electron microscopy of tests of Triticites ventricosus and Schwagerina sp. shows that the microgranular wall was secreted rather than agglutinated. Grains range in size from 0.5 to 6.0 μm, but grains larger than 4 μm are rare. Evidence that grains were secreted includes tight packing, uniform size and shape, and apparently homogeneous composition. Furthermore, scanning electron microscopy confirms the perforate nature of the antetheca and the nature of the keriothecal wall. Alveoli taper toward the tectum and pass through the tectum as tiny pores, enhancing communication between chambers and with the external environment.

The traditional model for the addition of chambers is rejected. Three ways in which new chambers may have been added to the test that are consistent with observations made here: 1) The antetheca may have thickened differentially, creating a substrate to which the keriotheca of the new chamber was attached; 2) Part of the tectum, septum, and keriotheca of the previous chamber may have been resorbed before calcite forming the new chamber was secreted, perhaps necessary because the tectum was an unsuitable substrate on which to attach the keriotheca of the new chamber; 3) A combination of the above may have occurred wherein the antetheca thickened differentially and was resorbed locally, providing a suitable substrate on which to attach the keriotheca of the new chamber. The last model is favored here because it best explains the shape of the septa and the configuration of the keriotheca of the chambers of most specimens. Nevertheless, the other two models are consistent with the morphology of some specimens.

Radiolaria extracted from two bedded-limestone and two limestone-concretion samples from the upper Llandovery of the Cape Phillips Formation, Cornwallis Island, allow the distinction between the spicular haplentactinid subfamily Secuicollactinae and the nonspicular Rotasphaeridae. This restores Secuicollactinae and returns Secuicollacta to the subfamily from the Rotasphaeridae. Secuicollactinae represent 36 percent of the fauna and are assigned to three genera, Secuicollacta, Diparvapila new genus, and Parvalanapila new genus; these form 27, five, and three percent of the fauna, respectively. The remaining one percent of the subfamily is unassigned. Rotasphaeridae form four percent of the fauna and are represented by Rotasphaera. Secuicollacta is diagnosed on the basis of the presence of an ectopic spicule in addition to several rotasphaeridlike primary units. The salient characters of Diparvapila include two lattice shells with an ectopic spicule on the medullary shell. Parvalanapila is diagnosed on the basis of a lattice sphere overlain by a labyrinthine layer and an ectopic spicule on the lattice sphere. New species described here are Secuicollacta malevola, S. sceptri, S. gliris, S. herrimani, S. segari, S. vallipuellae, S. resodiosae, S. glaebosa, S. teli, Diparvapila hicocki, D. saintrochae, D. larseni, Parvalanapila fleischerorum, and Rotasphaera severa. Four species of Secuicollacta are reported in open nomenclature, as are two of Diparvapila and two of Rotasphaera.

Two new species of dinoflagellate are described from the upper Cenozoic of the North Atlantic region. They are assigned to the goniodomacean genus Capisocysta Warny and Wrenn, 1997 emend., whose archeopyle uniquely forms by the extensive and exclusive dissociation of hypocystal plates. Capisocysta lata new species is recorded from the upper lower Pliocene Coralline Crag Formation of eastern England, the lower and upper Pliocene of the subsurface Great Bahama Bank, and as a living cyst from Phosphorescence Bay, Puerto Rico. Capisocysta lyellii new species is reported from the Coralline Crag Formation of eastern England. Capisocysta provides the only unambiguous example of a hypocystal archeopyle in the order Gonyaulacales and the only example of a hypotractal archeopyle in the division Dinoflagellata.

The spherical, proximate cysts have pre-formed lines of weakness that occur exclusively on the hypocyst, where they follow plate boundaries. Upon excystment, these sutures facilitate the separate release of plates 2–6″′, ps, 1p, and 1″″. Sulcal plates 1s and rs and postcingular plate 1″′ typically remain attached to the epicyst, forming a distinctive hyposulcal tab. The single antapical plate in C. lata is represented in C. lyellii by two plates (left and right first antapical homologues) that are released separately.

Capisocysta has a tropical to warm temperate distribution today. It thrived and perhaps formed blooms in tropical carbonate platform environments of the Bahamas during the Pliocene, and might prove to be a useful indicator of very warm intervals within the Pliocene of higher latitude regions including the southern North Sea basin.

To facilitate discussion of Capisocysta, several morphological terms have been modified or newly introduced. These terms more precisely describe archeopyle position and extent in dinoflagellates.

Permineralized fossils of the terminal Proterozoic (600–550 Ma) Doushantuo Formation, China, provide an unusually clear window on biological diversity just before the Ediacaran radiation. In the eastern Yangtze Gorges region, cherts in lower and upper Doushantuo carbonates preserve prokaryotes and protists from subtidal marine environments below and above fair weather wave base, respectively. Phosphorites in the Weng'an district to the south contain diverse acanthomorphic acritarchs as well as cellularly preserved thalloid algae. Twelve taxa of probable cyanobacteria are recognized. None is endemic to the Doushantuo Formation, and most have long stratigraphic ranges. The apparent restriction of two species to late Neoproterozoic and Cambrian rocks may reflect secular variation in taphonomic circumstance rather than evolution. Thirty-one species of spheromorphic and acanthomorphic acritarchs are recognized, about half of which occur elsewhere in rocks of the same approximate age. At least some of the eight formally described species of multicellular algae can be assigned with confidence to the Rhodophyta; these fossils provide a glimpse of structural and reproductive diversity in Neoproterozoic algae that is, to date, unique. Several reports of Doushantuo animal fossils have been published; most compelling are triact spicules identified in chert nodules. Along with more than two dozen taxa of compressed macrofossils preserved in carbonaceous shales from the top of the formation, Doushantuo permineralizations indicate that large animals radiated into a world rich in prokaryotic, protistan, and, even, multicellular diversity.

Endothyroid foraminifers are common in most marine Pennsylvanian units in the Appalachian Basin. The genera Planoendothyra Reitlinger, 1959, and Endothyranella Galloway and Harlton, 1930, are the dominant taxa. Scarce Endothyra Phillips, 1846, are restricted below the Desmoinesian. The greatest change in stratigraphic distribution of taxa occurs at the Atokan-Desmoinesian boundary.

Sixteen taxa are recognized. Five new species are proposed, including Planoendothyra orbiculata, P.? associata, Endothyranella kentuckyensis, E. inflata, and E. intermissa. Most taxa are assigned previously described American species using a cf. designation. Description and thin section illustration provide a basis for nomenclatural acceptance of these taxa.

Ten species of brachyuran decapod crustaceans, including four new species, Matutites miltonorum, Pororaria? granulosa, Eocarpilius blowi, and Glyphithyreus sturgeoni, are described from the Eocene Castle Hayne Formation in North Carolina. In addition, claw fragments suggest the presence of an additional four species. Analysis of the fauna within the formation, coupled with data from the enclosing rocks, suggests an environment of deposition in subtropical, clear water at shallow shelf depths. Wave and current energy were variable. Although no corpses were recognized and all the taxa were represented either by claw fragments or isolated carapaces, little abrasion or breakage was observed, which suggests that the material was deposited near the living site of the organisms. Many of the decapod taxa are congeneric with contemporaneous forms from Italy and with Miocene species in Hungary. Paleoceanographic modeling, using the Parallel Ocean Climate Model (POCM), forced by the GENESIS atmospheric circulation model, produces conditions of temperature, salinity, and ocean circulation that corroborate conclusions drawn from analysis of the Castle Hayne sediments and fauna and, additionally, yields similar conditions for the northern margin of the Tethyan region in the Mediterranean basin. Ocean circulation patterns demonstrate the feasibility of dispersal of subtropical organisms from the Mediterranean part of the Tethys across the Atlantic Ocean to the North American coastline.

Several specimens of the gigantic new species, Wewokella costata, have been recovered from the Upper Missisippian Hartselle Sandstone of Marshall County, east of Huntsville, in northeastern Alabama. The large sponges have flutted columnar growths and basic skeletons of triactines that are grossly encrusted or overgrown by calcium carbonate to produce massive fused skeletons. These are the oldest and largest specimens of Wewokella yet certainly identified. Wewokella costata has a skeleton with reduced numbers of triactines, but with extensive calcareous cement. The species could be in the lineage leading to the Inozoida Rigby and Senowbari-Daryan, 1996, which have spicule-free skeletons of sphaeroidal aragonite.

Bryozoans are an important part of the benthic marine fauna in a wide variety of modern environments and are found in rock forming abundance in a number of settings throughout much of the Phanerozoic. Bryozoologists and nonspecialists have grouped taxa into colonial growth forms (e.g., erect fenestrates or encrusting sheets), both to simplify analyses and because correlations exist between some colony growth forms and the environmental conditions in which the organism lived. These correlations allow for the possibility of paleoenvironmental analyses based on skeletons alone. Existing bryozoan colonial growth form classifications do not, however, fully exploit the ecological information present in colony form.

A new scheme is proposed here (Analytical Bryozoan Growth Habit Classification), which provides a list of colony-level morphological characteristics for bryozoan growth habits. This differs from previous approaches to bryozoan growth form analysis in that it is a classification of growth habit characteristics rather than a classification of morphological groups as such. The classification is based on eleven character classes, which describe the orientation of the colony and its occupation of, and placement in space. The overall colony shape is described based on the arrangement of modules in colonial growth. This classification provides a common ground for systematic comparison of character states among varied bryozoan growth habits. This approach allows for the evaluation of correlations among observed morphological character states and specific environmental conditions in which they develop. In addition, these growth habit characters can be used to recognize, characterize, evaluate, and apply more traditional growth form groups in broader studies.

Two new genera of Upper Silurian stromatoporoids in order Actinostromatida are described. Genus Bicolumnostratum Stock, with type species B. micum (Bogoyavlenskaya), is characterized by two kinds of pillars and nonaligned colliculi, and is assigned to family Actinostromatidae. Genus Acosmostroma Stock, with type species A. ataxium Stock new species, contains irregular micropillars and microcolliculi, and is assigned to family Densastromatidae. Two additional new species are Acosmostroma glascoense Stock and A.? cobleskillense Stock. A fourth species is A. tenuissimum (Parks). Bicolumnostratum is known from Ludlow- and Pridoli-age strata, whereas the occurrences of Acosmostroma are strictly Pridoli in age.

Calcareous articulate brachiopods are rare components of the high diversity, phosphatic, silicified, and epidote coated shelly fauna derived from Middle Cambrian (Floran-Undillan) allochthonous limestone clasts from the Murrawong Creek Formation, southern New England Fold Belt, northeastern New South Wales, Australia. Three taxa are described, the kutorginids Nisusia metula n. sp., and Yorkia sp. indet., and the protorthid Arctohedra austrina n. sp. Yorkia is documented from Australia for the first time. An unusual valve (possibly a brachial valve) of enigmatic affinity is also reported and illustrated. Generically, the taxa provide broad regional paleobiogeographic links with the “first discovery limestone” Member of the Coonigan Formation, western New South Wales, and the Current Bush Limestone in the Georgina Basin, northern Australia, and globally, with broadly contemporaneous sequences in western North America, Siberia, and South China.

An account of the systematics, biostratigraphy, ecological setting and the biogeographic implications of rugose corals from olistoliths of the Cabrières area is given. Corals of the lower member of the Izarne Formation are dated by conodonts as gronbergi Zone age, and include Lythophyllum sp. indet., Calceola sandalina (Linné), Tryplasma sp. A, Breviphrentis roharti Pedder new species, B. exigua Pedder new species, and Aqishaphyllum sp. A. Corals from the middle member of the formation include Frechocystis pertinax Pedder new genus and species, Calceola sp. undet., Rhizophyllum sp. aff. R. ukalundense Hill and Jell, Tryplasma enorme Pedder new species, Tryplasma sp. A, Breviphrentis sp. A, Platysmatophyllum halleri Pedder new genus and species, Pseudochonophyllum sentum Pedder new species, and Izarneophyllum barroisi (Frech) new genus. No age significant conodont has been recovered from the middle member. However, scutelluid trilobites, which, together with other trilobites, evidently used the underside of Izarne corals for shelter during molting, provide correlation with conodont sequences in the nappe domain to the north and southwest of Cabrières. From this line of evidence, the middle Izarne coral fauna is deduced to be nothoperbonus Zone age. The association of a variety of benthic trilobites, all with large eyes, provides evidence of a photic zone environment for the middle Izarne corals.

Rugose corals from the Izarne Formation belong to the Old World Realm and have nothing in common with similar age Rugosa of the Eastern Americas Realm. This implies that the dissolution of the boundary between these realms, which occurred in the Middle Devonian, did not begin before latest Emsian time.

The upper Lower Carboniferous, Serpukhovian (=Chesterian) productide brachiopod genus Gondolina, from China, is made the type for the new subfamily Gondolininae in the Aulostegidae. Sectioned specimens reveal an unusual posterior dorsal flap of shell partially covering the ventral interarea.

Relative differences between environmentally controlled variation and genetically controlled variation are important when investigating morphologic variation in general, especially when establishing species concepts. The colonial nature of bryozoans provides a means for distinguishing between the two sources; variation can be partitioned into within-colony (microenvironmental) and among-colony (environmental + genetic) components. For the Paleozoic order Cryptostomata, biologically and taxonomically significant morphologic characters are well defined and methods for recognizing morphotaxa are well established.

The importance of within-colony variation to the morphometric treatment of fenestrate species was assessed after the discovery of a large specimen of Hemitrypa sp. Variation within the colony was compared to variation among and within two congeneric species. The distribution of study segments across the colony allowed assessment of variation both along the growth axis and laterally between segments of approximately equivalent generational age. Repeatability of methods was assessed using data measured independently from identical segments by three workers.

Variation within the large colony is less than variation among congeneric species, indicating that genetic differences among species exceed variation resulting from combined phenotypic and genotypic sources within species. Neither astogenetic nor ontogenetic morphologic gradients are recognized. Variation between data collected from identical segments by pairs of workers falls within the range of variation for the entire colony. Thus, multiple workers can reproduce data to the finest level of meaningful resolution. Cryptostome morphospecies concepts are validated.

The potential for partitioning genotypic versus environmental variation in reduced, multidimensional morphospace is reinforced. Studies of microevolution and speciation may be designed that account for these factors.

Faunules of largely hexactinellid sponges have been collected from siltstones of Early Silurian Wenlock or latest Landovery age within the upper Road River Group from northern British Columbia. The assemblages include the new species: Protospongia columbiana, Hexatractiella pseudonevadensis and Cyathophycus akiensis. Other taxa described include the hexactinellids Protospongia conica Rigby and Harris, 1979, Hexatractiella nevadensis (Rigby and Stuart, 1988), Diagoniella sp., Gabelia pedunculus? Rigby and Murphy, 1983, and a specimen of the monaxonid demosponge Wareiella typicala Rigby and Harris, 1979. Also included is a fragment of what must have been a steeply obconical-cylindrical hexactinellid sponge of uncertain taxonomy; it has a skeleton of robust hexactines in an unquadruled net, above a root-tuft of 10-20 spicules. Other sponge impressions include small circular clusters of hexactines with radiating, to basketlike patterns and somewhat similar, isolated and dissociated, long probably roof tuft spicules and possible basal root tuft rosettes of monaxons. The faunules are similar to other outer continental margin, black shale, sponge assemblages of the Early Paleozoic Era, and include elements previously described from northern British Columbia and central Nevada.

Sinemurian and Pliensbachian Exogyrinae from northern Chile described herein as Nanogyra? cf. auricularis are considered the oldest members of the subfamily known to date. Comparisons with a large number of Jurassic Nanogyrini and aberrant Gryphaea species suggest that they are most closely related to Nanogyra? auricularis (Münster in Goldfuss) from the Toarcian of France, but probably not identical. Morphotypes of several Chilean specimens are transitional between gryphaeate and exogyrate forms, and their assignment to either Gryphaeinae or Exogyrinae appears arbitrary. In order to solve this taxonomic problem, the microstructures of Nanogyra? cf. auricularis and co-occurring typical Gryphaea species were examined and compared to a large database from previous studies. The results suggest that shell chambering is a feature common to all Exogyrinae but not to Gryphaea sensu stricto. Complex cross foliation and branching cross foliation are characteristic of both groups. However, they are more abundant in Gryphaea and apparently become phylogenetically reduced in the Exogyrinae. The transitory morphotypes and microstructures, especially of the Sinemurian specimens, are further evidence for the evolution of the Exogyrinae from the Gryphaeinae. Obviously, the Chilean specimens are very close in time and space to the origin of the subfamily. Thus, the lowermost Jurassic Andean back-arc basin of western South America is considered a plausible place of origin of the Exogyrinae.