Three new ophiuran species, Enakomusium whymanae n. sp., Aspidophiura? seren n. sp., and Ophiotitanos smithi n. sp., and an unnamed specimen assignable to the genus Dermocoma are described from the Callovian to Oxfordian Oxford Clay Formation of Great Britain. These determinations are based on new finds and a critical reassessment of historic specimens. The Oxford Clay ophiuroids represent two loose assemblages, one from the middle Callovian Peterborough Member and the other from the lower Oxfordian Weymouth Member. Both assemblages accord well with coeval midshelf mud bottom ophiuroid communities in terms of taxonomic composition and relative abundance of taxa. The British Oxford Clay ophiuroids are particularly significant as they are one of the rare instances where multiple species are represented, almost exclusively, by exceptionally preserved articulated skeletons. This provides an important window into the understanding of mid-Upper Jurassic ophiuroid paleobiology.

The nuculanid bivalve Costinuculana magharensis new genus new species is described from the middle to upper Bathonian Kehailia Formation of Gebel Maghara, North Sinai, Egypt. Costinuculana differs from other genera of the family Nuculanidae by the presence of opisthocline ribs along the rostrum. These ribs are variable in shape and size, straight to folded posteriorly, bifurcate ventrally and occasionally postero-dorsally, and cover an area ~45% of the total valve length from the posterior end. The life position of C. magharensis n. gen. n. sp. is reconstructed on the basis of a functional interpretation of its morphology and by comparison with closely related Recent forms. The asymmetrical commarginal ribs facilitated the burrowing process. The posterior oblique ribs are asymmetrical in cross-section with a steeply concave side in the burrowing direction and slightly convex side in the opposite direction. They probably kept the bivalve in a stable position once the desired depth had been reached. The thick oblique ribs probably also increased the strength of the rostrum and offered resistance against durophagous predators, being presumably partly exposed above the sediment-water interface. Based on the associated fauna, Costinuculana n. gen. lived in a low-energy environment characterized by a fine-grained, soft substrate.

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.

Carboniferous marine bivalves, especially those of early Late Carboniferous, are abundant and highly diversified in China. About 357 species, 76 genera in 29 families, of Carboniferous marine bivalves have been found from 103 localities throughout the country. This represents 83 percent of the genera (t = 92) and 85 percent of the families (t = 34) reported worldwide. These bivalve faunas are characterized by: 1) the high diversity of Aviculopectinidae and Myalinidae, in place of the highly diversified Pterineidae and Pterinopectinidae of the Devonian; 2) the presence of only three endemic genera (Cucullopsis, Palaeolucina, and Glyptoconcha); and 3) the endemic nature of most species, although some species are closely related to species in North America and Europe. The stratigraphic distribution of Carboniferous bivalves in the four faunal provinces of China is discussed stage by stage. All four faunal provinces of China had a close tie with the tropical to subtropical Tethys Realm during the Carboniferous. About 43.4 percent of the genera are epifauna with byssate attachment, which is almost four times more than the proportion present in living bivalve faunas.

Axiopsis eximia, a new species of thalassinidean shrimp, is described from an exposure of the Middle Eocene Lower Warley Hill Formation of South Carolina, U.S.A. Fossil axiids are rare, but this unique specimen is remarkably preserved as quartz free of enveloping matrix, having a nearly complete though distorted carapace, proximal parts of most thoracic appendages in situ but with distal articles missing, and extended abdomen with segments almost complete except for a few missing appendages. Presence of the bases of pleopods 1 and the elongate eyestalks surpassing the rostral apex, which it shares with the extant Axiopsis caespitosa group, place it provisionally in Axiopsis, which generally lacks first pleopods in males.

There appears to be an overwhelming urge in the study of earth sciences currently to discover the “cosmic generality.” Certainly, no observational and descriptive aspects of the study of earth history can be concluded until one has placed the observations into a broader context. On the other hand, there are not very many “cosmic generalities” and few lasting generalizations have been developed before the basic data have been gathered. When generalizations do precede observations, the former fall into the category of testable hypotheses or speculations, depending upon the overall plausibility of the ideas and the generosity of the reader.

Pegaster stichos n. gen. and sp., from the Cretaceous Chico Formation of Northern California, is the first-known fossil representative of the hitherto monogeneric Neomorphasterinae (Asteroidea: Asteriidae). Pegaster is morphologically similar to living Neomorphaster, again demonstrating the conservative evolution noted elsewhere among asteroids. Pegaster probably lived in a shallow shelf environment subject to strong storm action whereas Neomorphaster is known only from considerably greater depths; Pegaster provides a new example of an asteroid taxon excluded from shallower habitats through time.

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.

There has been some confusion in the literature regarding the present location of the type specimens of species described by Cope in 1886, which has resulted in the unnecessary erection of a neotype (Grande, 1982) for one of these species. This note is an attempt to trace the fate of these Brazilian specimens based on archival material in the Palaeontological Library of the British Museum (Natural History) (BMNH).

The pseudorthoceratid subfamily Macroloxoceratinae Flower, 1957, comprises a rare group of nautiloid cephalopods homeomorphic with the Actinoceratida in the development of a siphonal canal system. With the exception of Macroloxoceras Flower, 1957, from the Upper Devonian of Colorado and New Mexico, this subfamily has previously been reported only from the Mississippian of Europe. A specimen described herein from the late Viséan–?early Namurian Kennetcook Limestone of the Windsor Group of Nova Scotia, assigned to Campyloceras cf. C. unguis (Phillips, 1836), extends the range of the Macroloxoceratinae into the North American Mississippian. This discovery further provides new data on the complex siphonal morphology of this poorly known group of nautiloids, and supplements the recent documentation of the pseudorthoceratids in the Windsor Group cephalopod fauna (Edgecombe, 1987).

Famatinorthis cf. F. turneri Levy and Nullo, 1973, is an abundant component of a poorly preserved brachiopod assemblage in volcaniclastic rocks at one locality in the Arenig-age Shin Brook Formation in northeastern Maine. The brachiopod assemblage of the Shin Brook Formation has been classed as a Celtic biogeographic assemblage that is interpreted to have lived in cool water at mid- to high peri-Gondwanan latitudes. Famatinorthis turneri sensu stricto is one of the six brachiopod species known from coeval volcanicsrich rocks of continental margin affinities in the Famatina Range of northwestern Argentina; the presence of its congener in Maine supports the Celtic affinities of the Famatina assemblage, but its Ordovician location remains cryptic.

Three novel features are described in steinkerns of Hypomphalocirrus rugosus Linsley from the Middle Devonian Rogers City Limestone of Michigan. The first feature is located about one-half a volution adapertural of the terminal septum. It has the appearance of a typical molluscan muscle attachment scar and is interpreted as such. The two other features are more enigmatic. They have a less stereotyped appearance and location. The first is interpreted as a field of mantle point-attachments and the other as a product of partial shell dissolution. Comparisons with extant and fossil molluscs confirm that the two features ascribed to biologic origins are within the scope of molluscan soft-part and shell attachment morphologies.

A recent review (Haman, 1988) of the publication “Foraminiferal Genera and Their Classification” by Alfred R. Loeblich, Jr. and Helen Tappan, Van Nostrand Reinhold Company, New York, incorrectly indicated the date of its publication as “early 1988,” although adding, parenthetically, “The senior author refers to the publication date as December, 1987, A. R. Loeblich, Jr., January, 1988, written communication.”

Well-preserved, newly hatched coiled nautiloids from the late Paleozoic are relatively unusual. Thus, the recovery of a hatchling specimen from the Sosio Limestone (Permian, probably Wordian) of Italy that can be assigned to Sholakoceras cf. S. pleuronautiloides (Gemmellaro, 1890) is notable. The embryonic and posthatchling shell of S. cf. S. pleuronautiloides shows some morphological similarities to Recent Nautilus Linnaeus, 1758; however, some dissimilarities are significant, and these features have implications on the overall phylogenetic pattern exhibited by these organisms through time and the evolutionary processes that led to that pattern.

Calymenid trilobites are common components of diverse Silurian silicified faunas recovered from the Cape Phillips Formation of the Cape Phillips Basin, central Canadian Arctic Archipelago. Calymenids are represented in the Wenlock of the northern Laurentian region by only two genera, Diacalymene Kegel, 1927, and Arcticalymene new genus (type species A. viciousi new species). Calymenid diversity in any given fauna is never higher than two species, although these species may be numerically abundant. Arcticalymene became extinct during the Homerian, at which point calymenids disappeared forever from the northern Laurentian record.

Other new taxa are Arcticalymene cooki new species, A. jonesi new species, A. matlocki new species, and A. rotteni new species. Material representing at least two more species of the new genus is reported in open nomenclature. Diacalymene gabrielsi Siveter and Chatterton, 1996, is recorded from the Cape Phillips Basin.

Well-preserved upper and lower jaws of the aptychus-type found inside the body chambers of two specimens of the heteromorph ammonoid Pravitoceras sigmoidale Yabe, 1902 (Nostoceratidae, Ancyloceratina) are described from the Upper Cretaceous Izumi Group in Southwest Japan. They are similar in overall morphology to those of other nostoceratid and diplomoceratid ammonoids currently known, suggesting the morphological stability of the jaw features among these taxa. The equal size of the upper and lower jaws with beak-like rostral projection suggests that the jaw apparatus of this species might function to bite and cut up prey.

Anactolasma yukonanum new genus and species is described from the Pragian of Yukon Territory and is assigned to the Anactolasmatinae, a new subfamily of the Mucophyllidae Hill. Adult stages of Anactolasma resemble gerontic stages of Kobeha Merriam, although the genera have distinct ontogenies. Kobeha is revised on the basis of new material of its type species K. walcotti Merriam. The Papiliophyllinae Stumm are promoted to family status. Kobeha ketophylloides Merriam, from the Pragian of Nevada, and Endophyllum banksi Jell and Hill, from the Pragian of Tasmania, are restudied using new topotypic and other material. A new endophyllid genus named Murphyphyllum is erected for them, with E. banksi as type species. Asarcophyllum ramosum new genus and species, from the Emsian of Nevada, is made type species of a new cyathophyllid genus. Spongophyllum nevadense Stumm and S. expansum Stumm, both also from the Emsian of Nevada, are placed in the new genus, as is Asarcophyllum corona new genus and species, from the Emsian of Yukon Territory. Biostratigraphic settings, with emphasis on associated corals, brachiopods and conodonts, are given for the new and revised genera and species.

Low-latitude, deep-sea faunas remain poorly understood and described. Here, we systematically describe Quaternary deep-sea ostracodes from the Ocean Drilling Program (ODP) Site 925 (Ceara Rise; 4°12.2'N, 43°29.3′W; 3040 m water depth) in the equatorial Atlantic Ocean. Twenty-six genera and 52 species were examined and illustrated with high-resolution scanning electron microscopy images. Six new species are described herein: Pseudocythere spinae, Hemiparacytheridea zarikiani, Pedicythere canis, Xylocythere denticulata, Paracytherois obtusa, and Poseidonamicus sculptus. The results show that deep-sea ostracodes have a tropical faunal element that is distinctive from higher latitude ostracodes, and that is globally distributed in low latitudes. This tropical faunal component is possibly a Tethyan legacy of a fauna that was widely distributed in tropical and extratropical latitudes in deep waters during greenhouse conditions in the Cretaceous and early Cenozoic. Global cooling thereafter shrank its distribution, limiting it to tropical latitudes, perhaps with the relatively warm uppermost bathyal area acting as the source or refuge of this faunal component. Because similar present-day biogeographic patterns (i.e., presence and wide distribution of tropical deep-sea fauna) are known in other deep-sea benthic groups, this scenario might be applicable to the deep-sea benthos more broadly.

UUID: http://zoobank.org/552d4cb2-c0db-463a-ae3f-b2efcc0985df.

A nearly complete skeleton of an adult Hawaiian flightless ibis (Apteribis sp.) was recovered from a vaulted dry lava tube in association with remains of contour feathers. This is the first documentation of the genus Apteribis from the island of Lanai and provides the only record of the nature of the plumage in any of the prehistorically extinct species of birds known from the Hawaiian Islands. Light and scanning electron microscope analyses of structure of the pennaceous and plumulaceous (downy) portions of these feathers confirmed their placement with the ibises (Threskiornithidae). Within that family, the microscopic structure of the downy feathers is most similar to that of the New World ibises of the genus Eudocimus, thus corroborating molecular evidence of the derivation of Apteribis from Eudocimus. Plumage color was a combination of brown-black and ivory-beige/light brown suggestive of that of juveniles of Eudocimus. Plumage coloration in Apteribis may thus have evolved through the same processes of paedomorphosis that gave rise to flightlessness.

Environmental variability exerts a substantial control on massive, free-living, colonial corals such as Manicina areolata, influencing their shape and size as well as other characters, such as base morphology and colline complexity in meandroid forms. This species is well adapted for life in shallow, wave-swept waters due to its self-righting capabilities. Two different ecophenotypes of M. areolata, as defined by overall shape and base morphology, are present in two approximately coeval Pleistocene localities (PBA Quarry and Holey Land Canal) in southern Florida. These differences reflect adaptation to two depositional settings. Corallum size, shape, and oral complexity allow clear differentiation between these two environments. Greater corallum size, as primarily manifested by significantly greater height, tends to accompany increased grain size. The basal area and weight per cm2 of the coralla appear to be primary limiting factors in M. areolata's growth by controlling the coral's ability to self-right after overturning or causing sinking into less cohesive substrates. Complexity of confluent corallites increases with increasing size and colony volume. Thus, complexity of valley and colline patterns on the oral surface increases as a function of base area, so that collines developed on smaller, soft-substrate-inhabiting colonies are characteristically less complex than are those of larger, higher colonies. These complexities and variation in shape are apparently related to environmental conditions, predominantly substrate, water depth, and physical energy, resulting in recognizable ecophenotypes.