Although a number of brachiopod genera have been defined mainly from their internal structures, the fixity of those structures has rarely been investigated. Variability of the rather simple loops of two New Caledonian species of the Recent genus Stenosarina (Terebratulida), one species having a variant with endemic morphology, provides insight into the relationship between the two species. Procrustes methods based on landmarks are used. Intra-population variability is found to be of the same order of magnitude as inter-population variability. Moreover, the morphological distance between the endemic variant and the other specimens is greater than the distance between the two species of Stenosarina. The study also identifies a morphocline between the three forms of Stenosarina under study.

Previous descriptions of Tucetona lack a consistent system using diagnostic characters and only two recent Caribbean ‘species' are recognized. In this study, textural and structural features of the Tucetona shell are examined and used as the basis for comparison to other glycymerids and in the recognition of morphospecies. Standard diagnostic characters based mainly on the cross-sectional shape of ribs and on hinge teeth ontogeny are presented and used to distinguish six recent Caribbean morphospecies. The shell texture has been examined by light and scanning electron microscopy, showing the interior of glycymerid hinge teeth structured by two bundles of crossed lamellar texture. Whereas European Glycymeris examined for comparison correspond in their hinge plate textures to the one found in Tucetona, differences from a Caribbean Glycymeris sp. are described. Simple lamellar, crossed-lamellar and cone complex crossed-lamellar textures showed the same basic crystallite subunits.

Heliophyllum halli contains highly variable, mostly solitary rugose corals. Specimens reported here come from shaly beds of the Middle Devonian Hamilton Group in New York State. Early recognition of morphotype variation led James Hall to establish numerous species in the H. halli group that were later interpreted by John Wells in terms of varying life history. Life on unstable and/or soft substrates was facilitated for these corals by talons, root-like structures that allowed larval settling and post-larval development on hard particles such as echinoderm or shell debris. Variation in subsequent growth history is reflected in corallum shape and change in diameter. Straight growth axes reflect partial burial accompanied by vertical growth, while growth axis curvature resulted from unequal settling into substrate or alternatively, life at the surface of substrate, with sharp bends (geniculations) reflecting major changes in growth orientation. Decrease in diameter resulted from environmental stress, with greatest effects on the peripheral portion of the calice. Other major reactions to increased burial rate (through sinking or increased sedimentation) are epithecal secretion to form an outer wall for isolation of itself from surrounding sediment or decrease in polyp size as shown by terminal shrinking of the corallum diameter, at times nearly to zero. Yonge's (1940) summary of observations on living coral polyps suggests that the living H. halli was nonzooxanthellate, with an efficient system of feeding that utilized its multitude of tentacles without the help of cilia, which thus were able to generate currents to promote efficient sediment cleansing. Sediment shedding would also have been aided by polypal distension (swelling) above a reflexed calical margin.

Caribbean coral reef communities were restructured by episodes of accelerated biotic change during the late Oligocene/early Miocene and the late Pliocene/early Pleistocene. However, rigorous description of the effects of rapid biotic change is problematic because preservation and exposure of coral-bearing deposits is not consistent in all stratigraphic intervals. In the Caribbean, early and middle Miocene exposures are more rare than late Miocene and Pliocene exposures. One exception is the late early to early middle Miocene Tamana Formation of Trinidad, and old and new collections from this unit were studied to determine the timing of recovery after the Oligocene/Miocene transition. A total of 41 species of zooxanthellate corals were recovered from the unit, including 21 new records. Within these assemblages, species first occurrences outnumber species last occurrences by a factor of four (31 first occurrences and eight last occurrences). The extension of the stratigraphic ranges of species previously first recorded in Pliocene sediments has reduced an apparent Pliocene pulse of origination, indicating that the Pliocene/Pleistocene transition was largely a result of accelerated extinction against a background of near-constant origination. The fact that few species last occur in the Tamana fauna indicates that the Oligocene/Miocene transition was complete by the end of the early Miocene.

This study represents the first in a series tracing the early evolution of a dominant Caribbean reef coral, the Montastraea “annularis” species complex, using a combination of morphometric and phylogenetic approaches. It focuses on Costa Rica and Panama; additional geographic locations and reef environments will be treated in subsequent work. To distinguish species, new landmark methods are developed by comparisons with genetically characterized modern colonies from Panama. The fossil material consists of transverse thin-sections of 94 well-preserved specimens of M. annularis-like corals collected in Plio-Pleistocene reef sequences in the Limón basin of Costa Rica and the Bocas del Toro basin of Panama. The landmarks comprise 27 spatially homologous points, which define the thickness and structure of the corallite wall and associated costosepta. Bookstein size and shape coordinates are analyzed using cluster analysis and canonical discriminant analysis, and a total of 10 morphotypes are distinguished. Cladistic analyses are performed using characters derived partially from morphometric data. A matrix consisting of 16 taxa and eight characters is analyzed using global parsimony and a sister group of two species as the outgroup. The results reveal two distinct evolutionary groups, which are distinguished by the new corallite wall characters. One group contains one modern species, and the other contains a second; the relationships of the third are poorly resolved.

Despite the low number of equally parsimonious trees, high numbers of plesiomorphic taxa, long range extensions, and lack of agreement with genetic data indicate that the new characters alone are inadequate for completely interpreting evolutionary relationships, and more samples and characters are needed. Nevertheless, these preliminary results do show that three modern species of the M. “annularis” complex arose prior to accelerated extinction at the end of late Pliocene to early Pleistocene faunal turnover of Caribbean reef corals, and two may have originated younger than 4 Ma. Six or more new species may be represented in upper Pliocene to lower Pleistocene sequences in Costa Rica and Panama. Coexistence of predominantly pre- and post-turnover clades may have been responsible for the high diversity observed within the species complex in these two sequences.

The history of research on the “true” stromatoporoids, a presumably monophyletic group of sponges that occurred from the Ordovician through the Devonian, is examined in detail. Stromatoporoid published research is summarized in five categories: quantity of publication; biological affinities; systematics; skeletal microstructure; and paleoecology. Quantity of publication is measured from each of the 75 years. Moderate levels of publication in the late 1920s and 1930s declined in the early 1940s, and were reduced to zero for four years due to the impact of World War II. Levels similar to that of the 1930s returned in the 1950s, after which there was an overall increase until the mid-1980s, when levels began a decrease that persists today. The proportion of research on paleoecology has increased as research on systematics decreased through time. Post-Devonian forms assigned to the stromatoporoids are a polyphyletic grouping of several apparently unrelated taxa, possibly representing both Porifera and Cnidaria. Publications on the post-Devonian “stromatoporoids” amount to less than one-third that on the true stromatoporoids during the same 75 years.

The cladid crinoid order Poteriocrinida Jaekel, 1918 is a polyphyletic group that includes a variety of independent lineages united solely by the presence of ramulate or pinnulate arms. One of these lineages is the Rutkowskicrinidae new family herein assigned to the order Dendrocrinida, Bather 1899. Genera assigned to this new family include Rutkowskicrinus new genus, Decorocrinus new genus, Iteacrinus, Nassoviocrinus, Quantoxocrinus, Sacrinus, Sostronocrinus, ?Propoteriocrinus, and ?Schmidtocrinus. Members of this family are characterized by low conical cups with ridged thecal plates, U-shaped peneplenary radial facets bearing faint transverse ridges, a proximal median ridge on the posterior side of a long, narrow, predominantly straight anal sac, and pentagonal columns with one to two cirri per nodal. Arms in this family are highly variable, ranging from isotomous to heterotomous and pinnulate. The arms in the type specimen of Rutkowskicrinus patriciae n. sp. preserve all these various arm stages. The oldest presently known rutkowskicrinids occur in the Late Silurian (Ludlovian) of Australia and the Early Devonian (Pragian) of western Europe. The family diversified during the Middle Devonian (Givetian) in northeastern North America, and declined in numbers and diversity throughout the Late Devonian before going extinct in the Early Mississippian (Tournaisian).

The Glossocrinidae Goldring, 1923, containing Glossocrinus, Charientocrinus, Catactocrinus, and Liparocrinus, is also reviewed. This family, distinguished by a strongly recumbent anal sac in the B-E plane and a prominent median ridge extending the entire length of the anal sac, was derived from the Rutkowskicrinidae during the Middle Devonian (Givetian) and diversified in the Late Devonian before going extinct at the Frasnian-Famennian boundary.

The previously described rutkowskicrinid and glossocrinid genera listed above were assigned by Moore et al. (1978) to the dendrocrinid family Mastigocrinidae and poteriocrinid families Rhenocrinidae, Poteriocrinitidae, and Scytalocrinidae. Studied taxa include Rutkowskicrinus patriciae new genus and species, Rutkowskicrinus collieri new genus and species, Nassoviocrinus costatus (Goldring, 1954) new combination, Nassoviocrinus schultzei (Haarmann, 1921) new combination, Nassoviocrinus? duluki (Kesling, 1969) new combination, Nassoviocrinus? ornatus (Goldring, 1954) new combination, Nassoviocrinus? chilmanae new species, Decorocrinus arkonensis (Goldring, 1950) new combination, Decorocrinus cooperi (Goldring, 1926) new combination, Quantoxocrinus clarkei (Williams, 1882) new combination, Glossocrinus halli (Goldring, 1923) new combination, and Charientocrinus bellitubatus (Kesling, 1973) new combination.

Decapod crustacean specimens from the middle Eocene San Juan Formation in central Chiapas represent the first record of Eocene decapods in southern México. New taxa include: Dardanus mexicanus new species (Diogenidae), Lophoranina cristaspina new species, Notopus minutus new species (Raninidae); Verrucoides stenohedra new genus and new species (Xanthidae); Stoaplax nandachare new genus and new species (Goneplacidae); and Viapinnixa alvarezi new species (Pinnotheridae). Verrucoides verrucoides new genus and new combination from the Paleocene of Greenland represents a new combination. In addition, the fauna includes Callianassa sensu lato sp., Laeviranina sp., Calappilia cf. C. hondoensis Rathbun, 1930, Eriosachila sp., and indeterminate calappid and xanthoid taxa. This assemblage bears close relationship with coeval faunas in the Tethyan region of southern Europe and southern North America and with Paleocene faunas of Greenland, strengthening the evidence for previously described patterns of dispersal within the Decapoda.

A small fauna of 11 species belonging to 10 genera of Permian Brachiopoda from the lower part of the Qubuerga Formation outcropping near Shengmi village in the Qomolangma region of southern Xizang (Tibet) is figured and new taxa are described. New taxa are Quinquenella semiglobosa and Costatumulus shengmiensis. The fauna is most likely of Wuchiapingian (Djhulfian) age as indicated by the majority of the brachiopod species.

The Early Carnian (Upper Triassic) phaceloid coral originally described by Volz (1896) as Hexastraea fritschi, type species of Quenstedtiphyllia Melnikova, 1975, reproduced asexually by “Taschenknospung” (pocket-budding), a process documented herein for the first time. This type of budding is recognized only in the Amphiastraeidae, a family thus far recorded only from Jurassic-Cretaceous strata. Similar to amphiastraeids, Quenstedtiphyllia fritschi (Volz, 1896) has separate septal calcification centers and a mid-septal zone built of serially arranged trabeculae. The most important discriminating characters of the new amphiastraeid subfamily Quenstedtiphylliinae are one-zonalendotheca and radial symmetry of the corallite in the adult stage (in contrast to two-zonal and bilateral symmetry in the adult stage in Amphiastraeinae). Quenstedtiphyllia fritschi shares several primitive skeletal characters (plesiomorphies) with representatives of Triassic Zardinophyllidae and, possibly, Paleozoic plerophylline rugosans: e.g., thick epithecal wall and strongly bilateral early blastogenetic stages with the earliest corallite having one axial initial septum. To interpret the phylogenetic status of amphiastraeid corals, we performed two analyses using plerophylline rugosans and the solitary scleractinian Protoheterastraea, respectively, as the outgroups. The resulting phylogenetic hypotheses support grouping the Zardinophyllidae with the Amphiastraeidae in the clade Pachythecaliina (synapomorphy: presence of pachytheca). Taschenknospung is considered an autapomorphy for the Amphiastraeidae. This study is the first attempt to analyze the relationships of the Triassic corals cladistically.

Comprehensive analysis of the Cretaceous and Tertiary decapod crustaceans of the North Pacific Rim, focused primarily on the Brachyura, has resulted in additions to our understanding of the evolution and distribution of these animals, both in that region and globally. Hypotheses about changes in climatological and paleoceanographic conditions have not been extensively tested using decapod crustaceans, although they have been well-documented globally and for the North Pacific Ocean by sedimentological and other faunal evidence. Evidence from the occurrences of decapod crustaceans supports hypotheses obtained through these other means. Because the decapod fauna was studied independent of other faunas, it provides a means by which to compare and test patterns derived from molluscan and other faunal data. The brachyuran decapods show distinctive paleobiogeographic patterns during the Cretaceous and Tertiary, and these patterns are consistent with those documented globally in the molluscan faunas and paleoceanographic modeling. Additionally, the changes in the decapod fauna reflect patterns unique to the North Pacific Ocean. The decapod fauna is primarily comprised of a North Pacific component, a North Polar component, a component of Tethyan derivation, an amphitropical component, and a component derived from the high Southern latitudes. The Cretaceous and Tertiary decapod faunas of the North Pacific Ocean were initially dominated by taxa of North Pacific origin. Decapod diversity was highest in the Pacific Northwest of North America during the Eocene, and diversity has declined steadily since that time. Diversity in Japan was relatively low among the Decapoda until the Miocene, when diversity increased markedly due to the tropical influence of the Tethys and Indo-Pacific region. Diversity has remained high in Japan into the present time. The Cretaceous, Eocene, and Miocene were times of evolutionary bursts within the Brachyura and were separated by periods of evolutionary stasis.

Lower Ordovician sections in the type Ibexian area of western Utah contain a considerably more diverse trilobite fauna than has previously been reported. Reinvestigation of these faunas, based on new field sampling, allows a reassessment of the dimeropygid genera Ischyrotoma Raymond, 1925, and Dimeropygiella Ross, 1951. These taxa have been considered synonyms, but parsimony analysis indicates each is a well supported clade, and they are best recognized as sister genera. The number of species known from Ibex has been doubled, from four to eight, and morphological information is now available for most parts of the exoskeleton. New species include Ischyrotoma juabensis (Juab Formation), I. wahwahensis (Wah Wah Formation), Dimeropygiella fillmorensis (Fillmore Formation), and D. mccormicki (Fillmore Formation). The previously named species Dimeropygiella caudanodosa, D. blanda, and D. ovata are fully revised on the basis of abundant new material. Pseudohystricurus is a paraphyletic group, with species distributed as a basal grade of the Ischyrotoma/Dimeropygiella group.

I investigated the degree to which the interpretation of reef coral distribution data is influenced by the numerical and taxonomic scale of analysis in Pleistocene coral communities from the Caribbean Sea. Patterns of community differentiation analyzed at both species and genus levels showed only small differences using different numerical scales (relative abundance, rank abundance and species presence and absence). Whereas some differences were observed between species and genus level patterns, they had little effect on paleoecological interpretations. The greatest differences occurred when presence and absence analyses of assemblages sampled along 40-m transects were compared with those sampled along 40-m transects augmented by a one-hour search for rare taxa. These results suggest that paleoecological interpretations of Quaternary coral communities are robust to numerical scale of analysis at the species and genus level, and to taxonomic scale between the species and genus level. However, interpretations of community structure are sensitive to sampling intensity, geographic scale, and sample size.

Two new genera and ten new species of shallow-marine, warm-water gastropods are reported from several Upper Cretaceous formations found between British Columbia and southern California. The buccinid Zaglenum new genus is represented by two new species and the turbinellid Fimbrivasum new genus is represented by three new species. The nododelphinulid Trochacanthus pacificus new species is the first record of this genus in the Western Hemisphere, and the procerthiid Nudivagus? califus new species could be the first record of this genus on the Pacific slope of North America. The xenophorid Xenophora (Endoptygma) hermax new species is only the second known Cretaceous species of this genus on the Pacific slope of North America, and this species establishes that Endoptygma Gabb, 1877, is a valid taxon. The neritid Otostoma sharonae new species is only the fourth known Cretaceous species of this genus on the Pacific slope of North America. The ringiculid Ringicula? (Ringiculopsis?) hesperiae new species is the first Campanian record of this genus on the Pacific slope of North America and the first recognition of this subgenus in this area.

Gastropods that occur in the Anomalorthis brachiopod zone in the Spring Inlet Member of the Table Point Formation and in the Orthidiella brachiopod zone of the Shallow Bay Formation of the Cow Head Group are documented. Gastropods from western Newfoundland comprise part of the Toquima-Table Head fauna, and six of the seven genera described here are also found in Whiterockian strata of Nevada. Four species assigned to Monitorella Rohr, 1994, Maclurites Le Sueur, 1818, and Malayaspira Kobayashi, 1958, originally described by E. Billings in 1865 from Middle Ordovician (Whiterockian) strata of Newfoundland are revised. Five species of Helicotoma Salter, 1859, Malayaspira Kobayashi, 1958; Lytospira Koken, 1896; Rossospira Rohr, 1994; and Pachystrophia Perner, 1903, not previously reported from Newfoundland are also described. The probable opercula of Monitorella crenulata (Billings, 1865), and Maclurites emmonsi (Billings, 1865), are also illustrated for the first time.

The focus of this paper is to provide an overview of historical and modern accounts of scleractinian evolutionary relationships and classification. Scleractinian evolutionary relationships proposed in the 19th and the beginning of the 20th centuries were based mainly on skeletal data. More in-depth observations of the coral skeleton showed that the gross-morphology could be highly confusing. Profound differences in microstructural and microarchitectural characters of e.g., Mesozoic microsolenine, pachythecaliine, stylophylline, stylinine, and rhipidogyrine corals compared with nominotypic representatives of higher-rank units in which they were classified suggest their separate (?subordinal) taxonomic status. Recent application of molecular techniques resulted in hypotheses of evolutionary relationships that differed from traditional ones. The emergence of new and promising research methods such as highresolution morphometrics, analysis of biochemical skeletal data, and refined microstructural observations may still increase resolution of the “skeletal” approach. Achieving a more reliable and comprehensive scheme of evolutionary relationships and classification framework for the Scleractinia will require close cooperation between coral biologists, ecologists, geologists, geochemists, and paleontologists.

This paper presents a review of Cretaceous to Eocene genera and species of the Cantharus group of the buccinoidean neogastropod subfamily Pisaniinae, the description of two new genera and one new species, and a nonphylogenetic discussion of character evolution in this group. The new genus Ickarus is introduced for Tritonidea ickei Martin, 1914, from the Nanggulan beds (middle Eocene) of Java, Indonesia. Editharus (type species: Fusus polygonus Lamarck, 1803, middle Eocene of the Paris Basin, France) is a new genus with seven to nine species ranging from the early to late Eocene of Europe. Editharus is unusual in having a labral tooth formed at the angular junction between the adapical and abapical sectors of the outer lip. Editharus angulilabris from the Marinesian (early late Eocene) is a new species from the Paris Basin closely related to E. polygonus. The incidence and expression of several characters has sharply increased in the Cantharus group from the Paleogene to the Neogene. These characters include the presence of lirae (spiral ridges) on the inner side of the outer lip, the presence of a parietal tooth at the adapical end of the inner lip, and determinate growth (as inferred from a unique adult varix). These trends are also exhibited by other Cenozoic gastropod clades.

Silicified kirkbyoid ostracodes from the Cantabrian Mountains (Spain) bear a striking resemblance to those of the Carnic Alps (Austria and Italy). The Spanish ostracodes come from the upper part of the Cuera Limestones (Bashkirian-upper Moscovian), which are exposed along the Playa de la Huelga section (Ponga Nappe) in the coastal area of eastern Asturias, northern Spain. These fossils were collected from upper Moscovian limestones deposited in an outer-platform environment. Most of the material from the Carnic Alps was obtained from the Nassfeld Pass area (eastern Carnic Alps), near the Austrian-Italian border, in limestones of the Kasimovian-Gzhelian Auernig Group and the Lower Permian Rattendorf Group. The several Auernig Group limestones that contain silicified ostracodes were deposited in a shallow-marine environment.

Despite the differences in age (according to fusulinids and conodonts), these kirkbyoids are very similar and in some cases identical. Coronakirkbya pramolla new species and Kirkbya carniacantabrica new species occur in both areas. Two other pairs of species, Coronakirkbya krejcigrafi Becker, 1978, and Coronakirkbya carina new species, and Aurikirkbya cf. beckeri (Kozur, 1990) and Aurikirkbya carinthica new species, show close affinities, though they are considered to be different species. Most of the species described herein are either very rare or absent in other regions.

The close paleobiogeographic relationships between the Cantabrian Mountains and the Carnic Alps, documented previously only by brachiopods, are confirmed.

New shumardiid trilobites from Arenig to Early Caradoc deposits of the Argentine Precordillera include species of a revised Kweichowilla (K. salasae, K. sterrenae, and K. piojensis) and the new genus Changchowilla (C. sanjuanina and C. gracielae, and C.? carrerai). Conophrys fabiani new species occurs in the Early Tremadoc of the western Puna region, northwestern Argentina. Leoforteyia new genus is based on L. hintzei new species from the Ibexian of Utah. Published taxa recognized as new species are Conophrys rushtoni, Conophrys wrighti, Leoforteyia ludvigseni and Shumardia whittingtoni. Phylogenetic analysis suggests the differentiation of Shumardia Billings, 1862; Kweichowilla Chang, 1964; Changchowilla new genus; and Leoforteyia new genus as separate taxa and indicates that Conophrys Callaway, 1877, is a grade group. Silicified material provides a nearly complete growth series for Kweichowilla salasae, including the first protaspides known with confidence for the Shumardiidae. Additionally, ontogenetic material for K. sterrenae, C. sanjuanina, C. riojana (Benedetto and Cañas) and C.? carrerai is described.

Leoforteyia is restricted to the Ibexian-Whiterockian of western Laurentia; species of Shumardia are widespread in the Arenig to Early Ashgill of western Europe, Australia, Laurentia, China and Russia. Changchowilla is recorded in the mid-Late Arenig-Llanvirn of the Precordillera and in the Llanvirn-middle Caradoc of China. Argentine species of Kweichowilla are closely allied to Australian species, suggesting biogeographic affinities of the Precordillera to the eastern margin of Gondwana by the Llanvirn and Caradoc.

Functional morphology, occurrence in fine grained sediments, and association mainly with atheloptic and pelagic trilobites suggest that shumardiids were deposit-feeders that inhabited low light levels in low energy settings, with a limited ability to burrow in soft sediments.

Three new Miocene-Pliocene species of the cheilostome bryozoan Metrarabdotos from Venezuela are atypical in showing significant evidence that as many as half the colonies originated asexually (clonally) by “regeneration” from previously existing colonies, rather than almost exclusively from ancestrular zooids (products of metamorphosis of sexually produced larvae), as is characteristic of the genus. The extremely low proportion of zooids (less than two percent) recognizably committed to producing larvae (ovicelled) in these Venezuelan species agrees with that reported in a variety of Danian (Paleocene) genera in which clonal propagation has been reported to predominate. However, all but two of 17 other living and fossil species of Metrarabdotos also have fewer than two percent of their zooids ovicelled, even though all but one of more than 250 colony bases examined originated from ancestrulae. The lack of significant correlation in Metrarabdotos between frequencies of ovicelled zooids and of ancestrular colonies suggests that clonal propagation may not have diverted resources from sexual reproduction. This inference is supported by the retention in these species of a level of heritable morphologic variation (estimated by partitioning among-colonies and within-colonies variance in zooid characters) that is commensurate with that estimated for species of Metrarabdotos in which propagation was apparently entirely by sexual means. Thus, sexual reproduction throughout the genus was apparently sufficient to maintain the genetic diversity from which speciation could proceed at normal rates. As estimated by both cladistic and nearest-neighbor morphologic-stratigraphic methods, the three Venezuelan species occupy quite different positions in the inferred phylogeny of Metrarabdotos. Thus, the elevated level of clonal propagation in these species appears to be a response to local conditions, most probably high productivity associated with upwelling, that promoted more rapid vegetative growth while leaving the level of sexual reproduction unchanged.