The capitulum and peduncular armature of Arcoscalpellum toulmini Weisbord are described on new material from the lower unnamed member of the Porters Creek Formation in Wilcox County, Alabama. A few scuta and a possible tergum of a species Zeugmatolepas Withers bearing considerable resemblance to Z. cretae (Steenstrup) were recovered from the same locality.

Abundant, well-preserved specimens of a new peltocystidan mitrate carpoid, Jaekelocarpus oklahomensis n. gen. and sp., have been discovered in the Pennsylvanian (Morrowan Series) Gene Autry Shale Member, Golf Course Formation, in southern Oklahoma. The new carpoid postdates the youngest previously known carpoids (Middle Devonian) by about 65 million years. It is characterized by a small (to 4 mm in length) globose theca composed of six plates: two large adaulacophorals, two large marginals, and two relatively small plates that frame the main thecal orifice. One of the plates at the orifice bears a single stout spine. The theca and plates that comprise the theca display a high degree of bilateral symmetry. In contrast, the styloid has an asymmetrical array of spines and blades.

We hypothesize that most mitrates, including this one, were adapted to an infaunal life mode. The streamlined, generally symmetrical body shape is an adaptation to moving on or through the substrate. Spines and blades on the lower surface of the styloid and proximal aulacophore are inferred to be adaptations for gripping the substrate as the animal pulled itself backwards (aulacophore first). The main thecal orifice opposite the aulacophore was the site of both mouth and anus. Evidence for a sluggish, epifaunal life mode in the cornute carpoids includes the typically flattened, asymmetrical body, the presence of downward projecting spines and knobs on the marginal thecal plates of many species, and the specialized thecal pores and slits that faced away from the substrate.

At least four of the seven described species of Amyzon are valid species with doubtful status given to Amyzon pandatum Cope, 1874, and Amyzon fusiforme Cope, 1875. Amyzon gosiutensis Grande, Eastman, and Cavender, 1982, is a junior synonym of Amyzon aggregatum Wilson, 1977b. The Klondike Mountain Formation specimens examined from Republic, Washington, are identified as Amyzon aggregatum Wilson, 1977b. The known range of A. aggregatum is extended south to Republic, Washington, and southeast to the Laney Shale Member of the Green River Formation, Wyoming.

The lower River Bend Formation at the Martin Marietta New Bern quarry in Craven County, North Carolina, contains a diverse and abundant moldic molluscan fauna. This fauna, reconstructed by latex casts, suggests a Vicksburgian or a post-Vicksburgian, pre-Chickasawhayan age for the New Bern exposure. Forty-one molluscan species and subspecies are presently identified from the lower River Bend Formation, 11 of which are new: Turritella caelatura alani, Turritella neusensis, Galeodaria britti, Phalium newbernensis, Cymatium planinodum, Oocorys vadosus, Ecphora wheeleri, Lyria concinna, Scaphella saintjeani, Turricula (Orthosurcula) aequa, and Lucina (Stewartia) micraulax. This fauna is virtually identical at the generic level and similar at the species level to the Vicksburgian faunas of the Gulf Coastal Plain. About 37 percent of the New Bern species also occur in the Vicksburgian of Mississippi, although many of these species reach considerably larger sizes at New Bern. Apparent evolutionary transitions between previously known Vicksburgian and Chickasawhayan mollusks suggest a time of deposition intermediate between these two Oligocene stages.

Moderately high molluscan diversity, the abundance of characteristically warm-water genera, and associated carbonate-rich sediments suggest that the lower River Bend Formation represents a subtropical, open-marine, predominantly carbonate environment immediately seaward of a nearshore lagoonal or barrier island complex.

The lower River Bend Formation at New Bern differs faunally, climatically, and sedimentologically from the upper River Bend Formation in quarry exposures near Belgrade, North Carolina. The upper River Bend Formation contains a lower diversity molluscan fauna with marked dominance diversity and few warm-water taxa. It represents a slightly cooler nearshore, open-marine environment in a transitional siliciclastic-carbonate sedimentary regime. The considerable taxonomic and sedimentologic differences between the lower and upper parts of the River Bend Formation corroborate microfossil evidence suggesting that they represent temporally distinct depositional cycles.

Actinocrinites Miller from the Mississippian stratotype region of Illinois, Iowa, and Missouri are redescribed and redefined based upon study of the type material and morphometric analyses. Actinocrinites pernodosus, A. lowei, A. jugosus, A. gibsoni, and A. probolos n. sp. are recognized as valid species that occur in these strata. A combination of both metric and qualitative characters must be used to differentiate these species. Actinocrinites is known from the Montrose Chert Member of the Keokuk Limestone, the Keokuk Limestone, and the lower part of the Warsaw Formation, all late Osagean, in the stratotype region. In addition, Actinocrinites pernodosus and A. lowei are reported from the early Meramecian upper part of the Warsaw Formation, which is the first Meramecian occurrence of Actinocrinites in the stratotype region. Actinocrinites probolos n. sp. was ancestral to A. lowei, and the latter was probably ancestral to A. pernodosus.

Nomenclatural and systematic acts include the following: 1) Actinocrinites lowei (Hall, 1858) is the senior synonym of Actinocrinus brontes Hall, 1860, Actinocrinites lobatus (Hall, 1860), and A. unicarinatus (Hall, 1860); 2) Actinocrinites jugosus (Hall, 1860) is the senior synonym of A. augustatus Miller and Gurley, 1894; and 3) the concept applied incorrectly to A. lobatus by Wachsmuth and Springer (1897) represents a distinct species, Actinocrinites probolos n. sp.

Uppermost Cambrian and lowest Ordovician slope deposits in Highgate Gorge, northwestern Vermont, yield a succession of conodont faunas (and a few associated trilobite species) similar to that observed in coeval North American carbonate-platform sequences. Decimeter-scale sampling of a 15-m-interval in two sections comprising thin-bedded limestone–shale rhythmites alternating with thick-bedded debris flow conglomerates yielded 60 trilobite specimens and more than 5,000 conodont elements from 48 productive horizons. The new biostratigraphic control does not support earlier claims that the lowest occurrence of Cordylodus proavus in the Gorge Formation and presumably in other slope sequences is significantly older than the base of the C. proavus Zone in platform deposits; rather, it demonstrates the isochronous persistence of this boundary across the North American (Laurentian) shelf margin into Iapetan slope deposits. The common occurrence of the deep, cool-water conodont Eoconodontus alisonae and the agnostoid trilobite Lotagnostus hedini in the Eoconodontus Zone at Highgate Gorge makes it possible to extend the correlation even farther from the Laurentian platform into uppermost Cambrian strata in Kazakhstan and China. This new information greatly strengthens arguments in favor of using this zonal boundary for defining the international boundary between the Cambrian and Ordovician Systems.

In earlier studies of Highgate Gorge strata, composite treatment of biostratigraphic data from similar but non-correlative intervals (Zones 2 and 3) in two sections created an illusion of significant stratigraphic overlap of C. proavus with older faunas and direct association of some trilobite species for which overlap has never been established. Composite treatment of data from Zones 2 and 3 under designations such as “main zone’ or “upper zone’ should be discontinued and species that have been reported as occurring together in the “main zone’ should not be assumed (on the basis of that association alone) to have come from the same stratigraphic level.

A single specimen of the platyceratacean gastropod Raphispira showing one complete and one incomplete, slightly elliptical borehole was recovered from the Antelope Valley Formation in central Nevada. Circular boreholes may be formed by a variety of causes, but they are most commonly attributed to the predators. In the Paleozoic the holes are most common in brachiopods, both calcareous and phosphatic. This is the oldest reported occurrence in a calcareous shell. In most instances, if a hard-bodied form is consumed by a carnivore, little recognizable evidence remains; therefore, predator boreholes are helpful in determining trophic relationships.

Twenty-nine conodont species are represented in formations comprising the upper part of the Clinton Group and the Lockport Group at four localities in Niagara County, New York, and adjacent Ontario, Canada. Four previously unrecognized species of Ozarkodina represented in two samples from the Oak Orchard Formation are described. Ozarkodina sagitta rhenana (Walliser) and O. sagitta sagitta (Walliser) appear to form an evolutionary lineage in which the latter evolved from the former during the late early Wenlockian by slight modification of the Pa element. Elements in the other corresponding positions in their respective apparatuses are virtually identical.

The Williamson Shale, Irondequoit Limestone, Rochester Shale, and DeCew Formation of the Clinton Group belong in the upper part of the Pterospathodus amorphognathoides to the middle part of the Ozarkodina sagitta sagitta Chronozone, and are early to early middle Wenlockian in age. The Gasport, Goat Island, Eramosa, and Oak Orchard Formations of the Lockport Group belong in the middle part of the O. sagitta sagitta to the lower part of the Ancoradella ploeckensis Chronozone, and are early middle to late Wenlockian in age.

The coral-inhabiting archaeobalanid barnacle genus Eoceratoconcha Newman and Ladd, 1974, previously known only from the middle Miocene of Trinidad and questionably from the lower Miocene of Jamaica, is represented by a new species, E. weisbordi, in the coral Solenastrea bournoni Milne-Edwards and Haime from the upper Pliocene Pinecrest beds of Sarasota County, Florida. The new species differs from Miocene species of Eoceratoconcha in its larger overall size and more subdued wall plate ribbing, and is further distinguished from the type species, E. kugleri Newman and Ladd, in having a well-developed scutal adductor ridge and conspicuous tergal depressor muscle crests. The opercular morphology of E. weisbordi further supports the proposal of Newman and Ladd (1974) that Eoceratoconcha is ancestral to the pyrgomatid genus Ceratoconcha Kramberger-Gorjanovic.

Fossil ophiuroids (Echinodermata) have been recovered from rocks of the Comanche Series (Albian, Early Cretaceous) at Cerro de Cristo Rey, New Mexico. This is the first report of fossil ophiuroids from Mesozoic rocks in New Mexico.

Macro- and microfossils are commonly preserved as external molds as a result of decay or dissolution of soft and mineralized body parts after compaction and cementation of the surrounding matrix. The molds, which often preserve external features of the organism in great detail, are difficult to compare to other specimens. To enhance study, positive casts are typically made. Numerous compounds can serve as a casting medium (Rigby and Clark, 1965; Rixon, 1976). In microfossil studies latex rubber (Klapper in Winder, 1966; Ellison, 1987; Tull et al., 1988) and silicone rubber (G. Miller, personal commun.) are the most commonly used materials. An alternative technique is to photograph the mold directly using a scanning electron microscope (SEM).

The vincular furrow morphology of 19 species of Phacopidae is critically examined. The anterior part of the vincular furrow is much less variable than the posterior part of the vincular furrow, but it can be absent, shallow, deep, or have a slightly ventrally elongated boss. The posterior part of the vincular furrow can have pleurovincular pits (for reception of the thoracic pleural tip processes) or indentations for these processes, plus bounding walls that are variably indented laterally and very variable in vertical elongation. The functional morphology of the various elements of the vincular furrow is best explained by a paradigm of resistance to lateral shearing.

All elements of the vincular furrow in Devonian taxa had already appeared in the Early Silurian, but Early Silurian taxa are richer in diversity of elements. Some Devonian subspecies, essentially based on dorsal morphologies, show distinctly different vincular furrows. Cluster analysis of the data gathered on the vincular furrow complexes regroups the distinctly different Devonian subspecies and some Silurian subgenera. Other vincular furrows within the Phacopidae suggest that Reedops is near the Phacops logani complex and that the Phacopidellinae is a valid subfamily, but formal emendations within the family are not suggested because of incomplete data, notably on our knowledge of the distribution of vincular furrows. The use of the widely conceived genus Phacops Emmrich, 1839, over more recently described taxa such as Paciphacops Maximova, 1972, is presently favored, as this reflects more clearly current understanding of the systematics within the family Phacopidae.

Primary types of the North American taxa Phacops cristata, P. cristata gaspensis, and Acernaspis (Acernaspis) orestes are critically reviewed; significant changes of previous interpretations are suggested. Phacops cristata vitrea n. subsp. is erected. Thoracic pleural tip processes and anterolateral ventral pygidial processes are described in detail within Phacops rana rana and Acernaspis (Acernaspis) orestes. A pathological specimen of Phacops rana rana, with an injured eye, demonstrates that the individual did not revert to a primitive type of lens packing.

The existence of the Malvinokaffric Realm during the Silurian (Boucot, 1990) is based on the presence of three endemic brachiopod genera (Anabaia, Clarkeia, Heterorthella), and their absence in the coeval North Silurian Realm, where roughly 100 other brachiopod genera Aegiria to Zygospiraella are present. Within the Malvinokaffric Realm the vast reaches of the Paraná Basin, covering an area almost equivalent to the United States east of the Mississippi River, has previously yielded only Anabaia, and that from a single area. In light of this, the recognition of both Clarkeia and Heterorthella within the confines of the Paraná Basin is noteworthy.

Uppermost temaikan strata from southwest Auckland Province, North Island, New Zealand, have recently yielded a small fauna of Middle Jurassic ammonites previously believed to be endemic to the eastern Pacific borderlands, although a single fragment of the new species described below was previously reported in a large Tethyan assemblage from Papua, New Guinea, by Westermann and Callomon (1988). The New Zealand assemblage consists of the dimorphic pair Xenocephalites (♂) and Lilloettia (♀) with close morphologic ties to species from the latest Bathonian Steinmanni Standard Zone of the Andean Province (Riccardi et al., 1989). This new find permits direct time-correlation of the uppermost part of the Temaikan Stage (Marwick, 1951, 1953) with the East-Pacific latest Bathonian Steinmanni Zone and with the East-Tethyan Late Bathonian Macrocephalites apertus Association. The upper Temaikan Stage of south Otago Province, southeastern South Island, New Zealand, has also yielded rare representatives of the Tethyan Macrocephalitinae, so that the New Zealand area in the late Middle Jurassic was in the overlap area of Tethyan and East-Pacific Subrealms.

The Bridgeboro Limestone, a rhodolith- and coral-bearing limestone in southwestern Georgia, has been assigned to the Vicksburgian Stage (Lower Oligocene) of the Gulf Coast based on the occurrence of the bivalves Chlamys (Anatipopecten) anatipes (Morton) and C. (Lyropecten) duncanensis Mansfield. This assignment is further substantiated by the recent recognition of the distinctive bryozoan Tubucellaria vicksburgica Canu and Bassler. The Bridgeboro also contains the larger foraminifera Lepidocyclina (Lepidocyclina) mantelli (Morton), L. (Nephrolepidina) yurnagunensis Cushman, and L. (Eulepidina) undosa Cushman, an assemblage indicative of the Lepidocylina (s.s.) subzone of the Eulepidina Zone of Early Oligocene age. These foraminifera are also characteristic of the Duncan Church beds of the Florida panhandle, and an assemblage of isolepidine and eulepidine Lepidocyclina also occurs in the Glendon Limestone of Alabama. On the basis of larger foraminifera, macroin vertebrates, and physical stratigraphic relationships, we propose that the Bridgeboro, Duncan Church, and Glendon are biostratigraphically and lithostratigraphically correlative. The Glendon Limestone has been previously assigned to nannoplankton zone NP22, and also occurs within the Cassigerinella chipolensis–Pseudohastigerina micra planktonic foraminiferal zone, both of Early Oligocene age. Based on correlation with the Glendon, the age of the Bridgeboro is thus Early Oligocene (Rupelian), middle Vicksburgian.

The marine faunas from Patagonia, which are in need of a comprehensive revision, are particularly important in the understanding of the origin and evolution of the marine biota in the southern hemisphere during the final breakup of Gondwanaland during the Late Cretaceous–early Tertiary. The Eocene Río Turbio Formation in southern Patagonia (Argentina) contains a unique fauna of marine mollusks. This paper describes 35 species of bivalves from that unit. Nine of them are new: Nucula (Leionucula) guillermensis, Yoldia (Calorhadia) patagonica, Atrina rioturbiensis, Electroma patagonica, Venericardia (Venericor) carrerensis, Crassatella brandmayri, Solena (Eosolen) hunickeni, Pholadidea frenguellii, and Periploma (Aelga) primaverensis. In addition, 26 other species are also described, though their exact systematic relationships cannot at present be accurately established.

Most fossil echinoderms are unknown as complete skeletons because they have easily disarticulated appendages. This is the case of paracrinoids, which have a ruggedly constructed theca but fragile brachioles and attachment structures. In their monographic review ofparacrinoids, Parsley and Mintz (1975) figured only one species (Comarocystites punctatus Billings, 1854) showing essentially complete skeletal morphology. Paracrinoids have no good modern analogues and therefore the task of evaluating their lifestyles is complicated.

The hypostome of Glyptambon Holloway, 1981, provides additional morphological evidence that this genus is more closely related to the Siluro-Devonian subfamily Dalmanitinae than to Ordovician “Mucronaspidinae.” New species of Glyptambon are G. amsdeni n. sp., from the Ludlow Brownsport Formation in west-central Tennessee, and G. gassi n. sp., from late Wenlock strata of the Racine Formation in Illinois.