A preliminary comparison of Early Cretaceous paleocommunities in the Caribbean and contiguous Southern Western Interior provinces of North America suggests that the important factors for the differences were climate, basinal tectonics, sedimentation rates and the resulting substrates, environmental heterogeneity, evolution rates, and migration paths. Some paleocommunities were endemic to one province, and others were found in both provinces but differed in relative abundance patterns, species composition, diversity, and trophic structure.

The floras and the faunas encountered in the Mabou Mines Section of Cape Breton Island, Nova Scotia, are not greatly diversified. The floras are composed mainly of medullosean (seed) ferns referable to neuropterids and reticulopterids. Infrequently encountered are lycopod, pecopterid, mariopterid, alethopterid, fortopterid, sphenopterid, sphenophylls and cordaitean fossils. The fauna is characterized by Anthraconauta phillipsii, Carbonita spp., Leaia spp. and rare Gutschickia bretonensis representing a fresh-water, lacustrine paleoenvironment in a fluviatite regime. Shells possibly referable to Anthraconauta tenuis s.l. are rare.

In European chronostratigraphy (i.e., Heerlen), the age of the Mabou Mines Section encompasses middle to late Westphalian C to early Westphalian D. Correlation of the fauna with British chronozones is not without difficulty and a phillipsii Chronozone assignment is proposed which is somewhat lower (Westphalian C) than the floral correlation, an expected result.

Agglutinated siliceous foraminifera occur in the Middle Ordovician (Blackriveran) Mifflin Formation of the Platteville Group in northern Illinois. The fauna consists of globular saccamminids and a new form Reophax blackriveranus n. sp. which records the oldest validated representative of this genus. This marks the earliest known occurrence of agglutinated foraminifera with multichambered uniserial tests of progressively expanding chambers from the proloculus to the aperture. This early innovation of test morphology was probably developed to control unfavorable changes in the water chemistry of the environment.

Mifflin lithofacies consist of light gray, thin, wavy-bedded, lithographic limestone and fine-grained dolomite with green shale interbeds, thin calcarenite layers with graded bedding, a K-bentonite ash layer and hardground corrosion bedding surfaces. Mifflin biofacies include the foraminiferan fauna, brachiopods and molluscan shelly faunas, bryozoans, trilobites, ostracodes, echinoderms, solitary corals, conodonts, chitinozoans, scolecodonts, sponges and trace fossils particularly Chondrites.

The Mifflin strata were deposited on an exceedingly gentle slope off the Pecatonica carbonate platform which flanked the Wisconsin Arch. Thin Mifflin clinothem limestone beds wedge out into shales in the moderately deep (<200 m) aerobic starved basin in eastern Iowa. This occurred in south tropical seas during a eustatic rise in sealevel and major marine transgression. Reophax is associated with saccamminids in the benthos of the marine upper foreslope. Apparently slope-dwelling Reophax foraminifera of the Ordovician were displaced downslope into the basin by the rapid development and expansion of hyperamminids which occupy the lower and middle foreslope in the Mississippian.

Lower bathyal sediments representing portions of the Luisian and Mohnian stages of Kleinpell (1938) occur on a submarine ridge near Tanner Bank, offshore southern California. The presence of abundant and well-preserved calcareous nannofossils, diatoms, silicoflagellates, radiolarians and foraminifera allows accurate correlations with the onshore type sections of these stages. In terms of the calcareous nannofossil zones, the age range is from the Sphenolithus heteromorphus Zone to the Discoaster kugleri Zone. Although abundant benthic foraminifera indicative of the Luisian and Mohnian are present, they are accompanied by species more characteristic of the Pliocene Repettian Stage of Natland (1952) and the Pliocene-Miocene “Delmontian” Stage of Kleinpell (1938). Many of these latter species live today at lower bathyal depths (below 2,000 m), others occur in lower bathyal sediments as old as Oligocene, but are absent in the onshore type sections of the Luisian and Mohnian stages in coastal California. We ascribe their absence in onshore sequences to deposition at middle bathyal depths. The known chronostratigraphic ranges of several species are extended and five new species and two new subspecies of benthic foraminifera are described.

The following new taxa are described: Bolivina pelita n. sp., Cassidulinella inflata n. sp., Globocassidulina undulata n. sp., Cibicidoides mckannai miocenicus n. subsp., C. mckannai sigmosuturalis n. subsp., Pullenia fragilis n. sp., Parafissurina inornata n. sp.

The Cedar City Formation is divisible into three stromatoporoid biozones. These zones are differentiated by the mutually exclusive stratigraphic occurrences of the species 1) Syringostroma astrorhizoides, 2) Stromatoporella congregabilis and 3) Stachyodes crebrum. Chronologically, the zones range from late Emsian to early Frasnian. Lithofacies of the Cedar City are not restrictive as to the stromatoporoid species they contain.

Repaired shell breakage in Late Ordovician brachiopods from the Cincinnatian Series in the tri-state area of Indiana-Kentucky-Ohio may be described in increasing order of severity as scalloped, divoted, cleft and embayed. Concavo-convex brachiopod taxa display disproportionately higher frequencies of shell repair assigned to each category, whereas inflated, biconvex, plicate, sulcate taxa display disproportionately lower frequencies of shell repair. Certain plicate biconvex taxa lack examples of cleft and embayed valves. Plano-convex and dorsi-biconvex, costate taxa showed intermediate frequencies of shell repair, but lack representatives of embayed valves. Selective pressure for evolution of morphologic characters resistant to shell breakage may have favored phyletic trends of increasing size, geniculation and progressive development of a commissural ridge around the lophophore platform of the interior of the concave brachial valve of Leptaena and Rafinesquina. Size-frequency distributions for repaired and undamaged valves provide equivocal evidence of a size refuge from predator-induced shell breakage in Rafinesquina. Among the contemporaneous, potentially durophagous predators, nautiloids probably inflicted the sublethal injuries sustained by the brachiopods. The incriminating evidence includes a fragment of a crushing element imbedded in a valve of Rafinesquina that bears a very striking resemblance to calcified rhyncholites of Mesozoic to Recent nautiloids.

Early Devonian (Pragian-Emsian) rocks in the Xainza region of central Xizang (Tibet) yield a shallow-marine, carbonate-platform fauna of corals, brachiopods, dacryoconarids, nautiloids and conodonts, among which Tibetatrypa n. gen. is locally a prominent constituent. The fauna broadly resembles that of western Europe, the Altai-Sayan region, the Urals and western Qinlin province of China, but differs from the South China faunas. Tibetatrypa, related to the Silurian genus Nalivkinia, is the youngest and largest member of the subfamily Clintonellinae, and is the first Devonian brachiopod described from Tibet.

Mineralogical and microstructural analyses of Quenstedtoceras shells (Callovian, Poland) show that the outer shell material is preserved as nacreous aragonite, while the septal material shows different degrees of alteration. The septa in part are pyritized or show signs of cementation by equant/acicular calcite cement; paleoenvironmental interpretation of the least-altered outer shell material using the Sr/Na ratio suggests that the shell material was deposited in seawater which had a salinity of about 33 ppt and a range of about 32–35 ppt. Other data, such as Mn and Fe, imply that the oxygen level of the seawater was normal. The paleotemperature, using δ18O values with a salinity correction, was calculated to be about 11.0–14.5°C with an average water temperature of about 12.5°C. These paleoenvironmental parameters, in part, account for the faunal character of the Boreal Realm of the Jurassic.

Although past authors have regarded the Carydiidae as a European family, six species of Carydium are reported here from the Devonian of eastern North America. Two of these belong to a single morphocline common in the Hamilton shales; another (Carydium clarkei) is new. Due to lack of well preserved hinges most of these species were earlier placed in Nucula because serrations or striations on dental elements were mistaken for a taxodont dentition.

New data require modification of carydiid phylogenies of earlier authors. 1) Two independent pre-Devonian derivations from Lyrodesma are inferred. 2) Noradonta shergoldi, a carydiid-like lyrodesmatid from the Ordovician of Australia, is recognized as an important phyletic link between the Carydiidae and the Lyrodesmatidae. 3) The previous view of three distinct lineages within Carydium is not supported. Anamorphic data suggest as few as two main lineages and show two of the hinge types to be homeomorphic grades appearing separately or within one or the other of the main lineages.

Though too young to be directly involved in the early diversification of the Bivalvia, the actinodont, subheterodont, and pseudotaxodont hinge morphologies of Carydium supply models for the origin of heterodont and taxodont hinges. Anamorphic and other evidence suggests that both are iterative types, and fundamental differences between them may be few. Hence, their preeminence as diagnostic criteria among higher taxa is diminished.

Data from current research dealing with Jurassic ammonoids and stratigraphy of western North America are being stored in a computer file called AMMON using a data base management system. Each ammonite is described by up to 94 descriptors divided into the following six categories: taxonomy, quantitative morphology, qualitative morphology, stratigraphy, locality-catalogue information and general remarks. Data entry is facilitated by the use of a template on a video display terminal, the use of code numbers instead of full names and the bulk entry of hierarchic data. The computer can be used to speed fossil identification and retrieve geologic data by matching lists of descriptor states for a given specimen against those stored in the data bank. By interfacing with statistical analytical systems a ‘profile’ of a given taxon can be generated showing ranges of morphologic variation for any stage of ontogeny. Multivariate techniques are readily employed and subtle patterns of covariation more easily assessed. The data base may also be questioned to instantly generate taxonomic lists by zone, geographic area, lithostratigraphic unit, etc. (or any combination thereof) so that its research potential is considerable.

AMMON is a prototype meant to serve as a basis for discussion in developing a globally acceptable ammonoid data base. If code numbers for taxonomic, morphologic and stratigraphic data are standardized, information can be exchanged internationally using magnetic tapes and then decoded by the computer into any language. As data bases proliferate, they will inevitably make paleontological information more readily accessible to the specialist and non-specialist alike.

Fragmentary fossils from Late Devonian rocks, previously identified as phyllocarid arthropods, are referable to “Vermes.” Specimens identified as Dithyrocaris (=Mesothyra) sp. from the Chagrin Shale in northeastern Ohio are assigned to Sphenothallus cf. S. carbonarius (M'Coy). Thus, there are no records of rhinocaridid arthropods from the Chagrin. Fossils identified as “cercopods” of the echinocaridid, Echinocaris asiaticus Reed, from the Wetwin shales in Burma, are not arthropod remains, but are tubes produced by a gregarious worm. Echinocaris asiaticus is now represented only by a single partial carapace.

Comparisons of biotopes based on ternary plots and cluster analyses of living ostracode assemblages with those from subfossil assemblages from a small reef flat show that biostratinomic processes modify the assemblages before they are incorporated into the sediment of the reef flat. Selective preservation changes the assemblages by preferentially preserving robust carapaces over fragile carapaces. The thin-shelled Paradoxostomatidae, which are abundant in the algae-dwelling assemblages, are largely destroyed by biostratinomic processes and are represented by only a few individuals in the subfossil assemblages.

Mixing of algae-dwelling assemblages and sediment-dwelling assemblages results in a lower relative proportion of many species in the subfossil assemblages than in the living assemblages. The Leptocytheridae, which comprise a large portion of the sediment-dwelling fauna, are reduced in relative proportion in the subfossil assemblages as a result of dilution of the sediment-dwelling fauna with an abundant, algae-dwelling fauna.

Transportation of ostracode remains by wave-induced currents removes the patchiness that is characteristic of the biotopes of the living ostracode assemblages but does not completely homogenize the assemblage despite the close spacing of sampling and the small areal extent of the biotopes studied.

Five new ostracode genera and their type species are described from among 42 taxa obtained from silicified residues from the Quadrithyris brachiopod Zone and the upper pesavis and lower sulcatus conodont Zones of the McMonnigal Limestone at Ikes Canyon, Dianas Punch Bowl quadrangle, Nye County, Nevada. These are the beyrichiaceans Pseudomyomphalus spicatus n. gen., n. sp., and Dolichoscaphoides copelandi n. gen., n. sp., the hollinacean Eurekabolbina torquata n. gen., n. sp., the kloedenellacean Elenamarginia polenovae n. gen., n. sp. and the quasillitacean Prosumia peterseni n. gen., n. sp. Three of the five genera also occur in the partially correlative Windmill Limestone of Eureka County, Nevada, and may prove useful for interbasinal correlation.

A new species of phyllocarid arthropod, Tropidocaris salsiusculus, is described from the Upper Devonian Hampshire Formation near Rowlesburg, West Virginia. The organism was found in association with numerous trace fossils, at least one of which could have been produced by T. salsiusculus, and body fossils, including Lingula sp., several bivalve mollusks and smooth ostracods. Collectively, these organisms suggest a brackish-water environment of deposition. This report represents only the third record of phyllocarids from West Virginia.

Diameter, dip and orientation of burrows of the ghost crab Ocypode quadrata (Fabricius) were measured in back-beach areas: dune faces, dune crests, swales, blowouts and washover fans. Slope direction of the substrate at each burrow site was also measured. Results support three conclusions. First, burrow diameter increases landward. Second, burrow dip is related more to topography than to distance from shoreline; burrows dip more steeply in flatter areas (swales, blowouts, washovers). Third, a causal relationship exists between burrow orientation (as measured by the direction in which apertures point) and substrate slope; contrary to previous conclusions, burrow orientation is unrelated to shoreline direction. Burrow apertures simply point in the same direction as substrate slopes. In fact, on landward faces of dunes, burrow apertures point away from shoreline.

Approximately 10,000 determinable specimens of Pentremites pulchellus Ulrich (Blastoidea, Echinodermata) from a single quarry in the Pella Formation near Oskaloosa, Mahaska County, Iowa, have been examined for abnormal morphologic characters. The total frequency (2.7%) and the frequency among different types of abnormalities (ambulacral 29%; basal 46%; symmetrical 12%) are significantly different in the Pella material than in previously published studies (Wanner, 1932; Macurda, 1980). The greater frequency of abnormalities in the Pella Formation than in previous studies may reflect higher environmental stress because of variable temperatures or salinities or both. The kinds of abnormalities are the same among published studies, which suggest that the underlying biological causes of abnormalities were similar throughout the geologic history of the blastoids. Ambulacral abnormalities are symmetrically distributed, but the division and inversion of basal plates show an asymmetrical distribution as previously recorded by Macurda (1980). The Pella Formation is of Genevievian age (Upper Mississippian) based on the occurrence of Pugnoides ottumwa (White) and convex ambulacra in Pentremites pulchellus. Other unequivocal guide fossils are unknown in the Pella Formation.

An unusual occurrence of a colony of microcrinoids from shale within a fragment of a large orthoconic nautiloid body chamber is described from the Imo Formation (Mississippian, Chesterian) near Elba, Arkansas. The colony, about 70 individuals, consists principally of immature specimens that lack facets for the arms, and a few mature specimens with four or five arm facets. The crinoids are interpreted as record of a census population that was engulfed suddenly by mud. The crinoids are assigned to Allagecrinus coronarius Gutschick, 1968. The body chamber may have been broken during predation by other large cephalopods, or sharks, known from the Imo, or by post-mortem transport. The shell served as a firm substrate on which the microcrinoid larvae could settle and the convex sides may have provided some protection from currents.

The new flexible crinoid Para clidochirus n. gen. is described, with P. keyserensis (Springer, 1920) as the type species. A new species, P. schultzi, is described from the Late Devonian of Idaho.

The type specimen of Megalodelphis magnidens Kellogg, 1944, from the Late Tertiary of Florida, is not a long-beaked dolphin of the mammalian order Cetacea as it was originally described. The presence of splenial and angular bones in the holotype mandible, along with a suture for the surangular bone and an external mandibular fenestra, are reptilian characters unknown in the Mammalia. Details of the morphology and placement of the teeth and the conformation of the mandible reveal that this specimen belongs to a crocodilian, and should be referred to the long-snouted estuarine crocodile, Gavialosuchus americanus. Therefore, Megalodelphis magnidens Kellogg, 1944, becomes a junior synonym of Gavialosuchus americanus (Sellards, 1915). The edentulous “rostral” (actually mandibular) fragment referred by Kellogg to M. magnidens does represent a large, long-beaked odontocete cetacean; however, its fragmentary condition does not permit a positive allocation to genus. Pending a revision of the long-beaked odontocetes, this specimen is regarded as Odontoceti incertae sedis.