Supposed Upper Proterozoic strata in the southwest Taoudeni Basin, Guinea and Senegal, and from the Mauritanide fold belt, Mauritania, have yielded mostly poorly preserved small skeletal fossils of metazoan and protistan origin. Problematic, but possible echinoderm material and spicules of the heteractinid sponge Eiffelia dominate the Taoudeni Basin assemblage. The age of the material is not certain but the paleontologic data suggest an Early Cambrian age for the stratigraphically lowest faunas, and a Middle Cambrian age is possible for the stratigraphically highest collections.

The genus Tribrachiatus (all species of which are widely used stratigraphic markers) and its related genus Rhomboaster are studied in type samples and in five DSDP/ODP sites that have magnetostratigraphies and range from low through high latitudes. Rhomboaster calcitrapa, R. spineus, and R. bitrifida are shown to be junior synonyms of R. cuspis. Rhomboaster transforms into T. bramlettei by flattening of the nannolith. This makes the location of the first occurrence (FO) of T. bramlettei difficult and imprecise. The FO of Rhomboaster, however, is less ambiguous and more reliable for global stratigraphic correlation. Tribrachiatus contortus has a very short (< 1 m.y.) and consistent stratigraphic range. The FO of T. orthostylus is located very near the top of Chron C24r and slightly below the last occurrence of T. contortus. This study also presents detailed morphometric data on the changes from T. bramlettei to T. contortus to T. orthostylus, and calibrates their changes through time with magnetostratigraphy. This shows a detailed picture of the progressive evolution in this group as well as offers an age curve for high-resolution stratigraphic correlation.

Lercaritubus problematicus Flügel, Senowbari-Daryan, and Di Stefano, 1990, a problematic organism, was initially described from Lower and Middle Permian rocks of Sicily, was subsequently recognized in Upper Permian reefs of Oman and reefal limestones of the Tethyan realm. It is here described for the first time from North America, from the Middle Permian reefoidal Upper Capitan Limestone of the Guadalupe Mountains in New Mexico. Lercaritubus problematicus has a stratigraphic range of Lower to Upper Permian and occurs widely in Permian tropical reef deposits.

Late Permian reefal blocks exposed in the Ba'id area of the Eastern Oman Mountains yield a sphinctozoan assemblage that has not been studied previously. The sphinctozoan fauna described here is the first report of such an assemblage from the Arabian Peninsula. Approximately 70 samples were studied with respect to systematic paleontology, as well as frequency of taxa based on presence/absence lists. The sphinctozoans include 14 genera and 25 species. One genus (Rahbahthalamia) and five species (Amblysiphonella omanica, Salzburgia? irregularis, Welteria? hawasinensis, Thaumastocoelia? irregularis, and Girtyocoelia gracilis) are described as new. Amblysiphonella Steinmann (1882), Colospongia Laube (1865), and Sollasia Steinmann (1882) have the highest species diversity. On a generic level, Sollasia, Amblysiphonella, and Parauvanella Senowbari-Daryan and Di Stefano (1988) occur most frequently in the investigated samples. The described fauna exhibits close relationships to sphinctozoan faunas known from the Middle and Late Permian of China and Tunisia.

Endophyllum is described for the first time from North America. The occurrence of a single, large colony in Middle Devonian strata in New York is both biogeographically and environmentally anomalous: it belongs to an Old World Realm genus but was found in the Eastern Americas Realm, and it occurred in a gray, ambocoeliid-bearing mudstone, a facies in which morphologically complex corals are otherwise unknown. Available evidence suggests that the coral lived not far from where it was found, possibly on a hardground or bank a few km north of the outcrop. Endophyllum ciurcai new species is described.

Additional Whiterockian gastropods are described from the Antelope Valley Formation of Nevada. A new genus with affinities to Oriostoma is described as well as the new species Clathrospira glindmeyeri, Trochonemella antelopensis, and Raphispira martinensis. The lower ranges of Clathrospira Ulrich in Ulrich and Scofield and Trochonemella Okulitch, the species Liospira americana Billings and Raphistomina lapicida (Salter) are extended to the Whiterockian. The ranges of Raphispira Perner and the family Oriostomatidae Wenz are tentatively extended downward to the Whiterockian.

An anomalous pair of small, isolated calcareous sandstone bodies in the middle member of the upper Eocene Wagonwheel Formation, Wagonwheel Mountain, of the San Joaquin Valley, California, contain numerous articulated specimens of soft-bottom-dwelling bivalves. The lucinid bivalve Epilucina washingtoniana (Clark, 1925) dominates the fauna, which also sparingly contains the thyasirid bivalve Conchocele bisecta (Conrad, 1849) and the vesicomyid bivalve Vesicomya (Vesicomya) aff. V. (V.) tschudi Olsson, 1931.

The fossils in the pair of calcareous sandstone bodies, which are surrounded by deep-water silty mudstone barren of megafossils, most likely represent cold-seep communities in the upper bathyal environment. These cold seeps apparently were formed by diffusive flow through coarse sand-fill material in submarine channels.

Epilucina washingtoniana was previously known only from upper Eocene rocks on the Olympic Peninsula, Washington, and in Santa Barbara County, southern California. This species, along with a late Eocene species from Colombia, South America, are the earliest representatives of Epilucina. The Wagonwheel Formation contains one of the earliest records of Conchocele bisecta, which is a widespread Cenozoic fossil and is extant in the north Pacific. The species of Vesicomya in the Wagonwheel Formation is the earliest record of Vesicomya s.s. and has close affinity to Vescicomya (Vesicomya) tschudi Olsson, 1931, from the upper Oligocene of northwestern Peru, South America. As in the case of Conchocele bisecta, Vesicomya s.s. has not been reported previously from the Eocene of California.

Sections in the Basin Ranges provide stratigraphic standards for the Ordovician of the U.S., from which zones based on trilobites have been widely employed in regional correlation. This paper describes new trilobite faunas from a poorly known part of the succession, at the base of the Middle Ordovician (Whiterockian) in western Utah and eastern Nevada, and including the type Ibexian section near Ibex, Utah. The faunas are from the topmost Wahwah, and overlying Juab Limestone Formations, in strata equivalent to Zone L. Although well-preserved, none of the trilobites are silicified. All are typical of inshore carbonate, Bathyurid biofacies. The majority are new species congeneric with, but different from species from the overlying Kanosh Formation. The dominant bathyurid is the hitherto little-known Psephosthenaspis, after which the new Zone is named. A threefold subdivision of the Psephosthenaspis Zone is based on successive species of the genus. The lower two of these are probably equivalent to the Valhallan Stage, described from more offshore biofacies from Spitsbergen. Eighteen species are described, of which nine are formally named as new including: Goniotelina ensifer, Petigurus inexpectatus, Psephosthenaspis microspinosa, M. glabrior, Pseudoolenoides aspinosus, Ectenonotus progenitor, Kanoshia reticulata and Pseudomera arachnopyge. The type species of a remarkable new illaenid-like bathyurelline, Madaraspis magnifica gen. et sp. nov., is described.

The genus Cyphaspis Burmeister, 1843, is first known from the northern Laurentian Sheinwoodian. By the late Homerian, the genus had appeared in England and Baltica, and from the Ludlow through the Lower and Middle Devonian it had an essentially cosmopolitan distribution. The Mississippian Dixiphopyge Brezinski, 1988, may represent a relict distribution of Cyphaspis, and if so should be considered a junior subjective synonym. Cyphaspis is considered the sister taxon of Otarion Zenker, 1833. The oldest, Sheinwoodian, species of either genus are very similar, but the clades evolved to the point of gross morphological disparity in the Devonian.

New species from the Wenlock and probably Ludlow of northwestern Canada are Cyphaspis lowei, C. munii, C. buchbergeri, and C. mactavishi. New ontogenetic material of the Zlichovian C. dabrowni (Chatterton, 1971) further demonstrates the pervasiveness of the basic juvenile morphology of the tribe Otarionini.

The decapods Linuparus grimmeri Stenzel, Protocallianassa mortoni (Pilsbry) and Necrocarcinus (Cenomanocarcinus) vanstraeleni (Stenzel)? are described from the middle Turonian Semilla Sandstone Member, Mancos Shale, of north-central New Mexico. The main specimen of P. mortoni is unusually complete, consisting of a complete left first cheliped, parts of other pereiopods, and most of the abdomen. Both L. grimmeri and P. mortoni are reported for the first time from the southern Western Interior. The stratigraphic range of L. grimmeri is extended upward from the upper Cenomanian, and the range of P. mortoni downward from the Campanian.

A low-diversity camerate-rich crinoid fauna from the Qijiagou Formation, Taoshigo Valley near Turpan, Xinjiang-Uygar Autonomous Region, China was collected during field work in May, 1993. The crinoid fauna is dominated by species of Platycrinites. Other camerate crinoids include a species in the Paragaricocrinidae, Actinocrinites, a hexacrinitid, and an acrocrinoid. The only other non-North American occurrence of this latter family is Springeracrocrinus from the Moscovian of Russia. In addition to the camerates, there are several advanced cladid inadunates more typical of Upper Carboniferous crinoid faunas, including an erisocrinoid (possibly Sinocrinus), Graphiocrinus, ?Cromyocrinus, and an agassizocrinoid (Petschoracrinus) represented by partly fused infrabasal cones. A single radial plate with angustary facet may represent a cyathocrinoid. There also is a catillocrinoid, assigned here to Paracatillocrinus. The fauna, which resembles Moscovian crinoids described from Russia, is preserved in graded volcanic conglomeratic debris flows that overlie a carbonate mound and contain clasts up to 3 m in dimension. The crinoids are fragmentary, with many calyces seemingly torn into two or three pieces and dumped in with the pyroclastic debris. Camerates are represented by large thecal scraps consisting of numerous plates, or by large individual plates or circlets. Other fossils include rare solitary rugose corals, tabular bryozoans, Neospirifer, and other fragmentary brachiopods. We suspect that the crinoids may have been swept off of a nearby carbonate mound and deposited as debris-flow bedload.

A new trace fossil from the Lower Triassic of northern Italy is described. It is a sinuous resting trace of a bilaterally symmetrical worm-like animal. The anterior end is characterised by a pair of lateral projections. It most closely resembles an acorn-worm (class Enteropneusta) in morphology. As such, it is the only known resting trace of an acorn-worm from the fossil record.

A Frasnian composite standard provides a refined scaling for the thirteen-fold conodont zonation first developed in the Montagne Noire, France, but since replicated in North America, Australia, and now the Timan-Pechora region of Russia. Zones 4–13 are identifiable in seven cores from the Ukhta area of southern Timan and a core from the Bagan Field of the Khoreyver Basin. Scaling of the zones through graphic correlation demonstrates the diachronism in different sections of the bases of many conodont species, including those of zonally defining Palmatolepis. This can be effectively shown in a correlation diagram scaled to a composite standard based on graphic correlation, whereas it is obscured by the assumption of synchronism inherent in conventional zonal correlation charts.

Newly described species occurring in the Timan-Pechora region and elsewhere are Ozarkodina nonaginta, Ancyrognathus amplicavus, Mesotaxis johnsoni, Palmatolepis amplificata, P. mucronata, P. ormistoni, and P. timanensis. A number of other species described earlier from the region also occur outside Russia, mainly in Canada and Australia. Distribution patterns in the composite standard indicate close faunal connections between the Timan-Pechora, western Canada, and Western Australia.

Two species and genera of pteraspidids (Agnatha, Heterostraci), Blieckaspis priscillae n. gen., and Panamintaspis snowi n. gen. and n. sp., together with two undetermined species, are described from the lower part of the Lippincott Member of the Lost Burro Formation, southeastern California. The sharing of similar faunal elements with the Early Devonian assemblages of the Sevy Dolomite and Water Canyon Formation of Utah and Nevada, respectively, together with stratigraphic constraints on the age of the Death Valley fauna, suggest that these assemblages are age equivalent and have a late Emsian (inversus–serotinus Zones) age. The vertebrate-bearing unit of the Lippincott Member is interpreted as a channel-fill deposit laid down in an estuarine environment with low or fluctuating salinity.

A tooth battery, palatoquadrate, and a gill-arch element of Bobbodus schaefferi were collected from Late Pennsylvanian/Early Permian (Asselian) rocks near Manhattan, Kansas. Depending on the placement of the Pennsylvanian–Permian boundary, this specimen extends the upper limit of the species from the Virgilian (Gzelian) into the Gearyan (Asselian). The new range thus is Kasimovian to Asselian, a 15 my interval. Based on features of the palatoquadrate, the diagnoses of the order Eugeneodontida and the superfamily Caseodontoidea are revised. Bobbodus is the most primitive genus of the order Eugeneodontida.

Apparatus-based conodont taxonomy has organized the plethora of generic and specific names of form-based taxonomy into a more biologically and phylogenetically sound taxonomy (Schopf, 1966; Webers, 1966; Bergström and Sweet, 1966; Sweet and Bergström, 1972; Rhodes and Austin, 1981; Sweet, 1981, 1988). In the transition from form-based to apparatus-based taxonomy, some conodonts that are not very common, or that have only one or two element types in their apparatus, have remained in a state of form-based taxonomy limbo. An example of this is Trichonodella? tricurva (Schopf, 1966). This relatively uncommon species was known from only one element type (Schopf, 1966) and has not been used in biostratigraphy. Schopf (1966) questioned the generic assignment of T.? tricurva and noted its distinct morphology. Sweet and Bergström (1972) indicated that the type species of Trichonodella (Branson and Mehl, 1948) is a junior synonym of Plectodina aculeata, or of a closely related Plectodina species. Trichonodella? tricurva does not fit within the apparatus-based generic concept of Plectodina (Sweet, 1981), and it is therefore inappropriate to refer it to Trichonodella or Plectodina. No genus contains a tertiopedate element that is morphologically similar to the holotype of T.? tricurva (Schopf, 1966). Additional material from strata that are in part coeval with the stratum typicum of T.? tricurva supports the idea that T.? tricurva represents a new genus. The new genus Schopfodus is proposed for the conodont elements described by Schopf as T.? tricurva and the associated elements of its apparatus.

George frederic matthew studied the geology of eastern Canada during the late 1800's to early 1900's and became an authority on Cambrian paleontology. Matthew advised the Geological Survey of Canada as its Cambrian expert and published over 200 papers spanning topics from Precambrian stromatolites to Pennsylvanian arthropods to archaeology (Miller, 1988a; Landing and Miller, 1988). He described a number of trace fossils and problematica cited in Hantzschel (1975), but the location of some specimens and their status has been uncertain, sometimes considered missing. Most of the specimens have now been located and this paper summarizes their current location.