Mickwitziids are a unique group of brachiopods, known exclusively from the Lower Cambrian. Herein are described the new species Mickwitzia lochmana and M. multipunctata; both species are from southwestern North America. Mickwitzia muralensis Walcott, 1913, the largest mickwitziid, is reported here for the first time from the United States. This paper also discusses the distribution of mickwitziids, their shell structure, and the possible functions of mickwitziid punctae.

A study of Upper Triassic (Norian) thalamid sponges (“sphinctozoans”) from the Pilot Mountains, Garfield Hills, and East Range, Nevada, reveals an abundance of calcified sponges of the suborder Porata Seilacher. Two new species, Polycystocoelia silberlingi n. sp. and Neoguadalupia? norica n. sp., are added to our knowledge of five thalamid sponge taxa previously known from Nevada. All specimens have been neomorphically altered to calcite in a manner implying an original aragonite mineralogy.

At the species level, the sponges show a restricted distribution. Nevadathalamia cylindrica (Seilacher) is a species also occurring in Sonora, Mexico, and previously known from the Yukon of Canada, but all other species are endemic to west-central and northwestern Nevada. At the generic level, similarities exist with species known from the Tethyan Realm, the Yukon, and south China. The genus Polycystocoelia has been known previously only from Hubei, China, and from the Yukon Territory, Canada. Neoguadalupia was previously known only from the Lower and Upper Permian of China. The occurrence of this genus in Nevada constitutes the first record of the genus outside of the Permian System of China.

Even though Viriatellina gracilistriata (Hall) has been cited repeatedly, this work is the first modern description and illustration of the lectotype. Not only have the characters of the species not been well understood, the type locality and horizon for this species have been in error. Rare specimens associated with this species are described as a new species, Viriatellina porteri.

A new molluscan genus, Voskopiella, from the Lower Devonian of Bohemia is described and assigned to the Onychochiloidea. The type and only known species is Voskopiella barborae n. sp. from the Nowakia elegans Zone (uppermost Zlichovian, =Emsian) of the Suchomasty Limestone. Also discussed are its ontogeny, variability, and pathological development of ornamentation, as well as the mode of life, in order to resolve the problem as to whether onychochiloideans are torted gastropods or untorted paragastropods. A foliage supported mode of life or life in close association on or within algal mats is suggested for Voskopiella barborae n. gen. and sp.

The type material of Ilionia prisca (Hisinger) is redescribed. This species shows several basic morphological characteristics typical of Recent Lucinacea, including an anteriorly expanded shell with conspicuous diagonal sulci, a hypertrophied anterior adductor muscle scar, and a nonsinuate pallial line. It is believed to have been a suspension feeder provided with a posterior exhalant siphon and capable of forming an anterior inhalant mucus tube in the sediment. Ilionia prisca lived in a habitat unfavorable for most other bivalves, deeply buried in a soft, oxygen-poor and sulphur-rich mud, in which it oriented itself obliquely against the direction of water movement. Probably it lived in symbiosis with chemoautotrophic bacteria. It is suggested that Ilionia prisca is the oldest known deep-burrowing suspension-feeding bivalve.

A new bivalve, Yonginella amica n. gen. and sp., is described from the Silurian of Gotland. Although it has a straight hinge line with cardinal and lateral teeth indicating relationship with the Cyrtodontidae of the Arcoida, its external morphology (with a conspicuous diagonal ridge and sulcus) differs considerably from all previously described taxa of this group. Yonginella amica exhibits a shell shape suitable for soft muddy bottoms (“snowshoe” adaptation), and is interpreted to have been a nonsiphonate suspension feeder with a semi-infaunal, byssate mode of life.

Two new species of pectinid bivalves, Camptochlamys alaskensis and Chlamys aquilonia, are present in shallow-marine deposits near Ocean Point, northeastern Alaska, at about 70°N latitude. The precise age of these deposits is debatable, but paleontological and isotopic age estimates indicate placement near the Cretaceous–Tertiary boundary. The occurrence of Camptochlamys extends the chronostratigraphic and geographic range of this genus, previously unknown from any strata above the uppermost Jurassic (Tithonian) of Europe and unknown from any strata in North America. In contrast, the new Chlamys species represents an evolutionary advance beyond its nearest relative in the Maastrichtian of northern Europe and resembles Cenozoic members of its clade in certain features of shell microstructure. These new species are thus a microcosm of the debate regarding the age of these deposits and strengthen the hypothesis that the Ocean Point fauna lived in an Arctic Ocean basin that was isolated from the world ocean.

The Port au Port Group of western Newfoundland is a sequence of Upper Cambrian (Marjuman–Sunwaptan) shallow subtidal–supratidal carbonates and fine siliciclastics that are organized into three large scale sedimentary grand cycles. Low diversity trilobite faunas from the Marjuman and Steptoean portions (March Point and Petit Jardin Formations) include 17 species that are assigned to 16 genera; one species, Coosina kindlei, is new. Biostratigraphic analysis confirms earlier suggestions that the grand cycles boundaries record major intervals of onlap that can be recognized in other parts of North America and may be related to eustatic sea level rises.

The first Laurentian records of Pacificurus Ramsköld, 1986 are provided by Pacificus chilorhodus n. sp. (latest Llandovery?–early Wenlock, Mackenzie Mountains, Canada) and Pacificurus sp. A (early Ludlow, northern Maine). These closely related species represent an early divergence (minimally late Llandovery) from Australian/Asian congenerics.

“Complete” crinoids are rare fossils in the lower Paleozoic of Ireland. Cryptanisocrinus kilbridensis n. gen. and sp., from the Upper Llandovery (Telychian) Finny School Beds of the upper Kilbride Formation, County Mayo, is an anisocrinine homalocrinid and the first Irish lower Paleozoic flexible crinoid. The unique holotype is an external mold without counterpart that does not retain the anal series. Cryptanisocrinus kilbridensis has a kylixiform dorsal cup, a low but prominent, infrabasal circlet, low, triangular basals, arms that branch isotomously at least three times, and two interprimibrachial plates in each interray, the lower of which is the larger.

Acid etching combined with scanning electron microscopy (S.E.M.) accentuates a variety of conodont microstructural patterns as compared to unetched specimens. External and internal organic layers surrounding apatitic lamellae are found with internal organic layers apparently thinner than their external counterparts. This may imply partial removal of the outermost organic layer prior to secretion of the next lamella. Etching also provides evidence of internally preserved striate ornament. Polygonal etch artifacts and zones of crystallites aligned in small areas are interpreted as possible sites for apatite biomineralization.

Conodont faunas from the upper part of the Wadleigh Limestone, Alexander terrane, southeastern Alaska, are of Frasnian to early Famennian age and include the new taxa Polygnathus aspelundi nanus n. subsp., Polygnathus decorosus dutroi n. subsp., Polygnathus elegantulus sparus n. subsp., Polygnathus gracilis n. subsp. A, Polygnathus n. sp. A, Palmatolepis subrecta youngquisti n. subsp., and Icriodus subterminus uyenoi n. subsp. Four distinct age-determined faunal assemblages are recognized. The lowest is assigned to the Lower Palmatolepis rhenana Zone (the chronozones of Ziegler and Sandberg, 1990, are treated herein as time-rock equivalent assemblage zones). The next is exposed on three small islands just south of Wadleigh Island and is correlated with part of the Lower to Upper Palmatolepis rhenana Zones. The third assemblage, on the eastern side of Wadleigh Island from close to the top of the section, is correlated with part of the Palmatolepis linguiformis Zone. Nearby and overlying this is the fourth assemblage, which is correlated with part of the Lower Palmatolepis triangularis Zone and thus appears to be within the lower Famennian. These Wadleigh Limestone conodont faunas have affinities with faunas from equivalent horizons of the cratonic regions of the Northwest Territories and Alberta in Western Canada and to other faunas globally. The more provincial conodont taxa lend weak but positive support to brachiopod faunal evidence that places the Alexander terrane close to the North American craton during the Late Devonian.

The Woodford Shale of south-central Oklahoma was deposited in an offshore, quiet-water, oxygen-poor setting on the southern margin of North America in assocation with other dark organic-rich shales of the Upper Devonian–Lower Carboniferous black-shale facies. The basal Woodford was deposited unconformably over lower Paleozoic carbonate strata as a south-to-north transgressive unit during the Frasnian and early Famennian. Black shales and cherts lie directly above the basal beds.

Phosphatic shales in the upper Woodford contain a conodont succession characterized by three distinct environmentally controlled faunas. The lower fauna is characterized by Palmatolepis gracilis ssp., Branmehla inornata, Bispathodus stabilis, and Pseudopolygnathus marburgensis trigonicus, indicative of the Late Devonian Lower expansa Zone to Upper praesulcata Zone. The middle fauna, which spans the Devonian–Carboniferous (D/C) boundary, is characterized by Polygnathus communis communis and species of Protognathodus. On the Lawrence uplift the D/C boundary is disconformable, as indicated by the absence of Protognathodus kockeli before the first occurrence of Siphonodella sulcata. Light-colored phosphate laminae and beds, indicative of erosion and nondeposition, and a change in biofacies from an offshore palmatolepid–bispathodid fauna to a more nearshore, palmatolepid–polygnathid–protognathodid fauna indicate higher energy conditions and a lowering of sea level associated with the boundary interval. In the eastern Arbuckle Mountains the D/C boundary is apparently conformable, marked by a green shale interval containing a Protognathodus fauna. Species of Siphonodella, indicative of an offshore setting, characterize the third and youngest fauna. The Early Carboniferous sulcata, Lower duplicata, and Upper duplicata Zones are recognized in the upper Woodford. The Woodford Shale is conformably overlain by the “pre-Welden Shale’ and its equivalents, or unconformably overlain by the lower Caney Shale (Osagean?–Meramecian) in the northern outcrop regions and the Sycamore Formation (late Osagean?–Meramecian) in the southern Arbuckle Mountains.

Four new species are assigned to Vogelgnathus Norby and Rexroad because of the close similarity of their Pb and ramiform elements to those of the type species, V. campbelli (Rexroad). Recognition of the four new species requires that the generic diagnosis, based almost exclusively on the morphology of V. campbelli, be modified, chiefly to accommodate greater variation in Pa element morphology. Vogelgnathus dhindsai n. sp., V. gladiolus n. sp., V. kyphus n. sp., and V. pesaquidi n. sp. all possess abbreviated, carminiscaphate Pa elements. Spathognathodus postcampbelli Austin and Husri is reassigned to the genus.

The origins of Vogelgnathus are uncertain but V. gladiolus first appeared in the early Viséan and gave rise to V. pesaquidi. The latter species appears to represent the rootstock from which V. kyphus, V. campbelli, and V. dhindsai evolved. Vogelgnathus postcampbelli evolved from V. campbelli during the late Viséan.

Vogelgnathus campbelli and, to a lesser extent, V. postcampbelli have a wide geographic distribution; the four new species, however, are currently known only from Atlantic Canada, northern England, and southwest Scotland.

The occurrence of the large ichthyosaur Cymbospondylus in the Middle Triassic of Spitsbergen is recognized based on two different specimens. One consists of a semiarticulated string of 17 dorsal vertebrae with associated ribs and the other of an anterior dorsal vertebral centrum and possibly a caudal vertebral centrum. Both specimens can only be identified as Cymbospondylus sp. This record fills a gap in the distribution of Cymbospondylus, establishing this genus as the second most widespread Triassic ichthyosaur after Mixosaurus.

In a recent article, Narbonne et al. (1991) documented that the stratigraphic range of the chondrophorine Kullingia delicata continues above the the uppermost Precambrian (Vendian) into the lowermost Cambrian (Placentian Series) of the Avalonian faunal province. The revised text published in the Journal of Paleontology includes several references to Scenella Billings, 1872, as a Cambrian chondrophorine. This classification is in error and unfortunately serves to reinforce several recent reports that conclude that Scenella is a chondrophorine rather than a helcionacean mollusk.

In the paper by J. Keith Rigby (1991) in the January issue of the Journal, the Hungry Hollow Formation of southwestern Ontario is correlated with the basal Ludlowvillian Centerfield Limestone of New York. The new species of heteractinid sponge described in the paper was thus considered to be older than the designated type species of his new genus Gondekia, which is from the middle Ludlowvillian Wanakah Shale. The correlation was referred to as that of Rickard (1984) and was consistent with others going back several decades. It was also included in subsequent correlations based on conodont biostratigraphy (Johnson et al., 1985; Sparling, 1985) that are otherwise largely at odds with Rickard's conclusions. However, Brett and Baird (1985) provided convincing evidence that the Centerfield is a regressive unit between shales representing deeper water sedimentation, whereas the Hungry Hollow appears to be the basal unit of a transgressive sequence of strata and thus unlikely to be of the same age. Evidence for this was supplied by Landing and Brett (1987), who described a previously unrecognized disconformity beneath the Hungry Hollow and noted its regional significance. They also reported finding a single specimen of the conodont Polygnathus timorensis in the Hungry Hollow. This is the guide fossil for the Lower varcus Subzone, to which the Centerfield has been assigned, so placement of both units in at least the same conodont subzone was justified at that time.

During the course of field work for the invertebrate paleontology class at Bucknell University, part of an articulated polyplacophoran was discovered. Because these fossils are rare and because there are only two reports of North American Devonian polyplacophorans (Smith and Hoare, 1987), it is felt that this specimen should be described and illustrated.

When waikalasma was first recorded from early Miocene strata in New Zealand (Buckeridge, 1983) it was described as possessing eight compartmental plates but lacking basal whorls of imbricating plates. However, subsequent study and comparison of the holotype with extant Chionelasmus has shown that the remnants of several small plates remaining at the base of the rostrum represent the remains of two or three basal whorls (Figure 1). Furthermore, new evidence concerning the structure of the wall of the Chionelasmatinae has indicated not only that the true or median latus has been replaced by the carinolatus in balanomorphs, but that an additional or secondary carinolatus has been added in higher balanomorphs (Yamaguchi and Newman, 1990). The structure of the wall in Waikalasma can now be reinterpreted in light of these findings (Figure 2). It turns out, in terms of current phylogeny, that Waikalasma should be placed amongst the most primitive of the balanomorph barnacles, representing an important step in balanomorph evolution rather than simply an evolutionary offshoot as envisaged by Buckeridge (1983) and Foster and Buckeridge (1987) (Figure 3).

A nearly complete test and several test fragments of the irregular echinoid species Macropneustes mortoni (Conrad) were recently discovered in Lower Oligocene (Vicksburgian) strata of southern Alabama. To date, M. mortoni has only been reported from Upper Eocene (Jacksonian) sediments of Alabama, Georgia, and Florida (Cooke, 1959; Toulmin, 1977; Carter, 1987). This is one of the very few species of the diverse Eocene echinoid fauna of this region to survive the terminal Eocene extinctions.