The Mount Laurel Sand at Biggs Farm, Delaware, yielded a diverse ammonite fauna comprising Pachydiscus (Pachydiscus) sp., Placenticeras cf. P. placenta (DeKay, 1828), Placenticeras n. sp., Eulophoceras sp., Nostoceras (Nostoceras) draconis Stephenson, 1941, Didymoceras cheyennense (Meek and Hayden, 1856a), Anaklinoceras reflexum Stephenson, 1941, Anaklinoceras tenuicostatum n. sp., Oxybeloceras meekanum (Whitfield, 1877), Solenoceras annulifer Morton, 1841, Baculites ovatus Say, 1820, B. undatus Stephenson, 1941, Hoploscaphites vistulensis Błaszkiewicz, 1980, and Jeletzkytes compressus (Roemer, 1841). The last named two species occur in Europe and indicate an upper but not uppermost upper Campanian horizon. Several species also occur in the Western Interior and suggest correlation with the Didymoceras cheyennense zone and part of the Baculites compressus zone of the upper Campanian in that region.

Corynexochid trilobites of the Cambrian of Morocco are described and the subfamily Acontheinae is revised. With Kootenia beethoveni n. sp., Kootenia spp. indet., Strettonia sp. A, Clavigellus annulus n. gen. and sp., and gen. et sp. incert., the Moroccan Corynexochida comprise only a few forms that are almost exclusively restricted to the High Atlas Mountains. Biogeographical relationships are weak; strong relationships may exist with the faunas of the Shropshire area as already exemplified by some eodiscid and ellipsocephalid taxa.

Five species of camerate crinoids from the Middle Ordovician Dunleith Formation (Galena Group) of northern Iowa and southern Minnesota are described: Cleiocrinus regius Billings, Cotylacrinna sandra n. gen. and n. sp., Euptychocrinus skopaios n. gen. and n. sp., Abludoglyptocrinus charltoni (Kolata), and Eopatelliocrinus ornatus (Billings) n. comb. Archaeocrinus desideratus Billings is assigned to Cotylacrinna, and Glyptocrinus fimbriatus Shumard and Ptychocrinus longibrachialis Brower are placed in Euptychocrinus. The geographical affinities of the Iowa and Minnesota crinoids lie with adjacent localities in the northern midcontinent and the Appalachian province of Canada and New York. Preservation of various specimens implies that Euptychocrinus skopaios, Abludoglyptocrinus charltoni, and Eopatelliocrinus ornatus utilized parabolic arm fans. Cotylacrinna sandra is a specialized rhodocrinitid which is perhaps the largest completely known Ordovician crinoid with a stem length of over 91 cm and a total volume of about 45,740 mm3. The root morphology indicates an upright column and this animal towered above the associated echinoderms, which ranged from the substrate level to a maximum of 25 cm above the seafloor. Euptychocrinus skopaios is marked by dwarfed morphology compared to the closely allied E. fimbriatus, and it exhibits accelerated development of fixed brachs, number of brachials in and length of the arms, and closely spaced pinnules. The dwarfism is interpreted as a specialization for small size and adults of E. skopaios were only located about five or six cm above the substrate. New brachials and pinnules form at the distal arm tips of E. skopaios throughout ontogeny. Consequently, the length of and the number of plates in the food-gathering system are positively allometric relative to the crown volume. Food gathering capacity equals the number of food-catching tube feet times width of the food grooves and it is also augmented more rapidly than expected for an isometric crinoid. Although distantly related to euptychocrinids, most other Dunleith camerates, namely Abludoglyptocrinus charltoni, Eopatelliocrinus ornatus, and Cotylacrinna sandra, follow the same developmental trends of the food-gathering system observed in Euptychocrinus skopaios. Comparison of the pinnulate camerates and three species of ramulate cladids and a disparid from the Dunleith reveals some striking contrasts. At equivalent crown volumes, the camerates are characterized by more numerous arm branches in the form of pinnules, more narrow food grooves, more closely spaced tube feet, and longer food-gathering systems with more plates and greater capacity. The Dunleith camerates were adapted for catching smaller food particles using more numerous and more closely spaced tube feet located on more extensively branched filtration nets than the associated cladids and disparid. The differences can be attributed to taxonomy and presumably phylogeny, that is camerates versus cladids and disparids, and/or morphology in the presence of pinnules versus ramules.

Three types of alimentary canals (=midgut) occur in the Annelida and non-trilobite Arthropoda: 1) a sagittal tube with metamerically paired diverticula related to the number of somites; 2) a tube that is constricted slightly between somites; and 3) a simple tubular gut that may taper slightly backwards to the anus. At least two of these three types (1 and 3) occur in the Trilobita. Pterocephalia and Olenoides share the first type with the probable sister taxon to the Trilobita, Naraoia (Nectaspida), and this is probably the plesiomorphic condition for the class. Varying feeding habits may well have made this character homoplastic within each of these groups. The preservation of parts of the alimentary tract in specimens of Upper Cambrian Pterocephalia n. sp. (McKay Group, British Columbia) was probably a function of taphonomic and/or very early diagenetic changes that resulted from the type of food preferred by that trilobite. Other trilobites from the same beds do not have their soft parts preserved. The alimentary structures are preserved in a different fashion from, apparently unattached to, and an order of magnitude larger than genal caeca that occur in this taxon. Thus, genal caeca are regarded as imprints of circulatory rather than alimentary structures.

Energy dispersive analysis of a fragment of preserved alimentary tract of Pterocephalia n. sp. showed the presence of Ca, Si, Al, Fe, P, K, Na, and Cl. These alimentary tracts are composed of a complex mixture of minerals that probably includes clays, detrital quartz, carbonates, phosphates, and oxides or hydroxides. The structure of these dark fillings is microcrystalline. The presence of detrital minerals as part of this mixture would suggest that this trilobite was a deposit feeder.

A fossilized nest found in a 17 Ma paleosol on Rusinga Island is similar in many respects to those constructed by bees. The nest consists of subellipsoidal cells arranged in paired, parallel rows, which are themselves arranged in clusters. Typical cells average approximately 6 mm by 3.5 mm, and have curved dorsal surfaces and nearly flat ventral surfaces. The nest is here referred to a new ichnospecies: Celliforma habari. The cell shape and nest architecture are most like those of modern bees of the subfamily Halictinae (Apoidea: Halictidae), and probably were constructed by bees with a societal structure that was at least communal and quite possibly more highly social. The nest suggests a subhumid to humid climate and angiosperm-dominated vegetation for Rusinga Island during Early Miocene time.

Examination of extremely well-preserved cuticle samples from the Maastrichtian retroplumid crab, Costacopluma mexicana Vega and Perrilliat, collected in the Difunta Group in Nuevo León State, Mexico, documents the preservation of corpses in an anoxic microenvironment produced by decomposition of soft tissue of the organisms. All four cuticular layers, epicuticle, exocuticle, endocuticle, and membranous layer, as well as pore canals and tegumental glands, can be recognized. There is no evidence of resorption that accompanies molting. X-ray analysis of the cuticle indicates that the organic matrix was replaced by carbonate-hydroxyapatite, that the original calcitic material was replaced by quartz, and that the replacement proceeded from the outer and inner surfaces of the cuticle toward the interior. The specimens were interpreted to have been preserved in an organic-rich, restricted lagoon in which pH was changed by periodic influxes of fresh water.

When not found with fossil bone, gastroliths (fossil gizzard stones) may be hard to identify. One attribute that is potentially useful is their high degree of surface polish, presumably caused by abrasion in the animal's gizzard. A novel video laser light scattering instrument is used to characterize the surface roughness of suspected moa gastroliths, as well as similar (non-gastrolith) quartz rocks that were polished by ocean waves. The instrument is fairly successful at distinguishing between the two types of samples.

Samples from the Dumugol Formation were collected from eight measured sections and two cores in the so-called Baegunsan Syncline, located between eastern Yeongweol and Samcheog areas, Kangweon-Do, South Korea. A total of 7,813 identifiable conodonts were recovered from 146 samples. They are classified into 24 multielement species referable to 16 genera, and 37 form species belonging to 17 genera; six species are newly described: Distacodus dumugolensis, Parapanderodus acontiformis, Scolopodus longibasis, Scolopodus n. sp. A, Triangulodus dumugolensis, and Oistodus(?) sp. The Dumugol Formation is divided biostratigraphically into four conodont zones, viz, Chosonodina herfurthi-Rossodus manitouensis, Glyptoconus quadraplicatus, Paracordylodus gracilis, and Triangulodus dumugolensis zones in ascending order. These zones are correlated with those of the early Ordovician conodont faunas of North America, northern Europe, China, Australia, and Iran. The Dumugol Formation ranges from late Tremadocian to early Arenigian in age. The boundary between these two series lies between 70 and 100 m above the base of the Dumugol Formation in each of the sections.

Speocarcinus berglundi n. sp. is described from the Imperial Formation in Riverside County, California. Although the Imperial Formation spans late Miocene through late Pliocene time, the part of the unit that bears crabs has been radiometrically dated as late Miocene. The identification of a new species was based upon comparison with four extant species and represents the first documented fossil occurrence for the genus. The occurrence of this new species suggests that the genus may have originated in the Pacific and, during the Miocene, dispersed through the Isthmus of Panama to the Caribbean. Two of the specimens exhibit parasitism by Bopyridae (Isopoda).

The genus Otarion Zenker, 1833, first appears in the Wenlock simultaneously with Cyphaspis Burmeister, 1843, as the oldest known species of each occur together in the southern Mackenzie Mountains of the Canadian Northwest Territories. The genera are unambiguous sister groups, a relationship supported most compellingly by a uniquely derived and distinctive pattern of juvenile cephalic spines, shared also with the Carboniferous genus Namuropyge Richter and Richter, 1939. This sister group relationship permits the development of a robust and stratigraphically correlated hypothesis of relationship among the adequately known species of Otarion, Otarion, Cyphaspis, and Namuropyge constitute the tribe Otarionini. The Mississippian genus Dixiphopyge Brezinski, 1988, may also belong to Otarionini. Namuropyge is a paedomorph, likely derived from a Degree Six or Seven meraspid of an older species of uncertain position in the Otarion–Cyphaspis clade.

Three Wenlock species of Otarion occur in stratigraphic succession in a single section in the Mackenzie Mountains. Analysis of morphological change with time, and of sequential ontogenies, suggests that the Silurian history of the genus was dominated by incidents of peramorphosis.

New species are Otarion huddyi, O. beukeboomi, and O. coppinsensis. Otarion brauni Perry and Chatterton, 1979, is revised.

Borealarges n. gen. (type species B. reedi n. gen. and sp.) is a group of trochurine trilobites of mainly northern Laurentian distribution, closely related to both Richterarges Phleger and Terranovia Maximova. Richterarges is restricted to a Laurentian Ludlow-Přídolí clade of unambiguous monophyly. Taken together, the genera form a monophyletic subdivision of Trochurinae. Phylogenetic relationships within this clade are poorly resolved. The precise relationships of some members of the group are difficult to determine at present, and these species are referred to Borealarges sensu lato. Members of Borealarges are ubiquitous elements of silicified Wenlock–Ludlow trilobite faunas contained in debris flows of the Cape Phillips Formation of the central Canadian Arctic. At present, known post-Wenlock diversity of Borealarges is exclusively northern Laurentian, although this may be a function of lack of study in other areas. New species include B. reedi, B. morrisoni, and B. tuckerae, and B. s.l. B. calei. Borealarges mikulicorum (Perry and Chatterton) is revised.

The shoo fly Complex of Late Devonian and older Paleozoic age is a regionally extensive rock assemblage in the northern Sierra Nevada of northern California. It consists chiefly of a coherent unit of phyllite, quartzose sandstone, and chert, and a melange unit (Hannah and Moores, 1986). Several limestone lenses in the Taylorsville area comprise the Montgomery Limestone (Diller, 1892, 1908; McMath, 1958; Figure 1). The Montgomery was long considered to be Silurian, largely on the basis of corals, brachiopods, and cephalopods (Diller, 1892, 1908; McMath, 1958; Berry and Boucot, 1970; Merriam, 1972). However, recent analyses of the biota indicate an Ashgill (middle Maysvillian–Gamachian) age (Boucot and Potter, 1977; Harris, personal commun. cited in Hannah and Moores, 1986, p. 790; Potter et al., 1990b; present study).

This paper describes new species of Ostracoda from Late Cretaceous (late Santonian) oyster reefs of the Eutaw Formation of eastern Alabama. The reefs are composed almost exclusively of Ostrea cretacea Morton, with rarer occurrences of the oysters Exogyra upatoiensis Stephenson and Lopha ucheensis (Stephenson) and the bivalve Anomia preolmstedi Stephenson. Total thickness of the reefs is about 30 m, and the reefs are a major topographic feature across most of Macon and Russell Counties, Alabama, a distance of about 60 km. The reefs are interpreted to have been backbarrier sediments deposited under brackish conditions.

Eight species of ostracodes are identified, including five new species described herein. The fauna is typically well preserved, and includes males, females, and juveniles. New species include Haplocytheridea? eutawensis, Antibythocypris dimorphicus, A. nephotrema, Brachycythere asymmetrica, and Eocytheropteron mutafoveata. Also discussed and illustrated are Cytherella tuberculifera Alexander, Haplocytheridea renfroensis renfroensis Crane, and Fissocarinocythere gapensis (Alexander).

Tyrannosaurids are a well-supported clade of very large predatory dinosaurs of Late Cretaceous Asiamerica. Traditional dinosaurian systematics place these animals within the infraorder Carnosauria with the other large theropods (allosaurids, megalosaurids). A new cladistic analysis indicates that the tyrannosaurs were in fact derived members of the Coelurosauria, a group of otherwise small theropods. Despite certain gross cranial similarities with the large predators of the Jurassic and Early Cretaceous, the Late Cretaceous tyrannosaurids are shown to be the sister group to ornithomimids and troodontids, which share a derived condition of the metatarsus. This clade is found to be nested within Maniraptora, which is a more inclusive taxon than previously recognized. The atrophied carpal structure found in tyrannosaurids and ornithomimids is derived from a maniraptoran condition with a large semilunate carpal, rather than from the plesiomorphic theropod morphology.

The taxa “Carnosauria” and “Deinonychosauria” (Dromaeosauridae plus Troodontidae) are shown to be polyphyletic, and the Late Jurassic African form Elaphrosaurus is found to be the sister taxon to Abelisauridae rather than a primitive ornithomimosaur. Purported allosaurid-tyrannosaurid synapomorphies are seen to be largely size-related, present in the larger members of both clades, but absent in smaller members of the Tyrannosauridae. The remaining giant tetanurine theropods (Megalosaurus and Torvosaurus) were found to be progressively distant outgroups to an allosaurid-coelurosaur clade. The inclusion of the Tyrannosauridae within Maniraptora suggests a major adaptive radiation of coelurosaurs within Cretaceous Asiamerica comparable to contemporaneous radiations in various herbivorous dinosaurian clades.

Museum and field restudy of Cryptolithus from all known geographic and stratigraphic occurrences in eastern North America shows that the principal variable character in this genus is the number of fringe pit arcs. Because this character varies within populations and even single individuals, it cannot be used to distinguish the earlier, typologically defined species of the genus. Instead, a neotype is designated here for the type species, Cryptolithus tessellatus Green, 1832, and morph designations are used for all pit arc variants. Over the time span considered, the species increased the number of pit arcs, but the ecological and evolutionary mechanisms responsible cannot be identified with certainty.

Four specimens of blastozoan and crinozoan echinoderms are described from the Lower Ordovician El Paso Group in the southern Franklin Mountains just north of El Paso, west Texas. Cuniculocystis floweri n. gen. and sp., based on two partial specimens, appears to be a typical rhombiferan in most of its morphologic features except that it lacks pectinirhombs and instead has covered epispires (otherwise known only from Middle Ordovician eocrinoids) opening on most of the thecal plate sutures. The covered epispires in Cuniculocystis indicate that some early rhombiferans had alternate respiratory structures and had not yet standardized on pectinirhombs, a feature previously used as diagnostic for the class Rhombifera. Bockia? elpasoensis n. sp. is a new eocrinoid based on one poorly preserved specimen that has a small ellipsoidal theca and unbranched brachioles attached to a flat-topped spoutlike summit. It is the earliest known questionable representative of this genus and the only one that has been described from North America. Elpasocrinus radiatus n. gen. and sp. is an early cladid inadunate crinoid based on a single well-preserved calyx. It fits into a lineage of early cladids leading to the dendrocrinids and to Carabocrinus. Several additional separate plates, stem segments, and a holdfast of these and other echinoderms are also described.

Anapteris van winkle (1919) is a distinctive corbulid genus characterized by the left valve having a peculiar wing-like flare anteriorly and both valves having the posterior area set off by a prominent umbonal keel (Vokes, 1945; Keen, 1969). Heretofore this genus has been known only from the type species, A. regalis Van Winkle (1919; 1921), which has been recorded only from the upper middle Eocene (Bartonian) Piney Point Formation in Virginia (Ward, 1985). The purpose of this note is to record the second known occurrence of Anapteris. The genus is present in the lower middle Eocene of southern California, where it is represented by Corbula wardii Hanna (1927).

Upper Devonian (Famennian) sequences were sampled at two sections in the Canning Basin, Western Australia, and a section at Bactrian Mountain, Nevada, over an interval ranging from the Upper crepida Zone into the Lower marginifera Zone of the standard conodont zonation for the Famennian. Over 30,000 conodont elements have been identified among 43 species and subspecies within six genera. New complete and partial multielement reconstructions are illustrated for: Palmatolepis falcata, P. glabra prima, P. loba, P. minuta minuta, P. perlobata perlobata, P. perlobata maxima, P. quadrantinodosalobata, P. rhomboidea, P. schindewolfi, P. subgracilis, P. wolskae, Polygnathus cf. P. diversus, P. glaber glaber, P. nodocostatus nodocostatus, P. subnormalis, and P. cf. P. triphyllatus. The reconstructions are based on stratigraphic occurrence, detailed morphologic similarities, and a few exceptional low-diversity faunas. Additionally, Palmatolepis adamantea n. sp. is proposed based on the Pa element.

A more precise understanding of the taxonomic boundaries of Palmatolepis is achieved through knowledge of the entire apparatus, rather than confined to the Pa elements. Reconstructions presented here provide a more comprehensive understanding of the range of morphologic variation that exists in Palmatolepis, and show that a single generalized elemental plan can be demonstrated for all members of the genus. The differences in the non-Pa elements can thus be used to refine taxonomy and increase understanding of phylogenetic relationships at the specific and subspecific level.

The stem (column plus attachment structure) of the extant, Pacific bourgueticrinine crinoid Phrynocrinus nudus A. H. Clark is described, and some notes provided on the crown. The attachment structure is a simple, terminal discoidal holdfast, typical of an obligate encruster of hard substrates and probably derived neotenously from the attached larval stage of an ancestral isocrinid. The column is long and composed of robust columnals. Unlike isocrinids, the mesistele, rather than the proxistele, is the most flexible part of the column. The proximale columnal has an inflexible articulation with the basals; a new proximale grows irregularly between these ossicles. Articulation between the proximale and columnal 2 is synostosial, but all more distal articulations are synarthrial. Proximally and in the dististele, articular facets are rounded, but for much of the column facets are strongly elliptical with offsets approaching 90° in many columnals. However, offset of fulcra is variable between columnals, indicating that it is not a consistently useful criterion for separating species in the bourgueticrinines.

Silicified encrinurine trilobites from Telychian strata of the Whittaker Formation east of Avalanche Lake, District of Mackenzie, Canada, include Briania jeffersoni n. gen. and sp. and Johntempleia pamae n. gen. and sp. Morphology of Briania suggests an origin near the divergence of Pacificurus from the variolaris plexus. Johntempleia also includes Rhuddanian–Aeronian diversity from Scotland, and is resolved as the basal branch of the punctatus plexus. Briania jeffersoni and Johntempleia pamae co-occur with rare taxa of the variolaris plexus (“Nucleurus” spp. A and B) in a deep-water assemblage dominated by Cromus and the odontopleurid Stelckaspis. Stratigraphic range data for encrinurine genera identify the late Telychian to early Sheinwoodian as a time of taxonomic turnover.