Previous studies of the Toarcian of the North American Cordillera have mentioned the rare occurrence of Paroniceras in the Queen Charlotte Islands. Recent work has identified the presence of Leukadiella in the Middle Toarcian of the Queen Charlotte Islands, the Spatsizi area, and the Hazelton area. They occur with Rarenodia planulata, Peronoceras pacificum, Peronoceras verticosum, and Phymatoceras cf. P. pseudoerbaense. The Leukadiella specimens are well preserved and generally larger than those found in the Mediterranean region. Taxa present in North America include Paroniceras sternale, Leukadiella ionica, Leukadiella amuratica, Leukadiella aff. L. helenae, and Leukadiella aff. L. ionica. Morphologically Leukadiella is closely related to such genera as Hildaites and Hildoceras and is more suitably placed within the subfamily Hildoceratinae rather than the Bouleiceratinae. The distribution of Leukadiella and Paroniceras indicates the influence of the Hispanic Corridor linking western Tethys and the eastern Pacific during the Middle Toarcian.

A new genus of mylagaluid rodent from the Miocene of the Great Basin, Hesperogaulus, is described, and to it two new species, H. gazini and H. wilsoni (type species) are referred. This genus differs from all other genera of later Tertiary mylagaulines in having: large bosses of rugose bone on the anterior end of the nasal bones; lower slope of the occipital bone; and unique separation of the anterior branches of the forked parafossette on the upper premolar.

Hepserogaulus n. gen. represents a distinct lineage of mylagaulids that has been separate from other members of the family since the early Barstovian. This genus is geographically limited to the Great Basin. Other later Tertiary genera of mylagaulids show geographic limitations to other parts of the continent as well.

Lapparia sp. A of Toulmin (1977), from the early Eocene Hatchetigbee Formation of Alabama, is referable to the Tethyan genus Volutilithes and is conspecific with Voluta clarae Harris. This is the first certain record of Volutilithes in the Paleogene of the Gulf Coastal Plain and only the third record of the genus in North America. Trans-Atlantic migration of this tropical genus to the New World apparently occurred during the early Eocene. Its northward expansion into the higher latitudes of Alabama and southern California was probably in response to early Eocene climatic warming.

In addition to Volutilithes, many other molluscs with Tethyan affinities are present in the Paloegene deposits of the Gulf Coastal Plain. These Tethyan elements, however, differ from those reported from the Eocene of peninsular Florida. The presence of a filter-bridge barrier, the Suwannee Channel, between the eastern Gulf shelf and the Floridian carbonate platform during the Paleogene may account for this difference.

Fossiliferous Late Silurian strata have not previously been recognized in the folded Appalachians south of central Virginia (Berry and Boucot, 1970). In this note, we report that the Red Mountain Formation at two localities in northern Alabama (Sparks Gap and Clear Branch Gap in Red Mountain near Birmingham, Figure 1) has yielded fossils like those of the Cobleskill Limestone (Pridolian, latest Late Silurian). The Red Mountain Formation in this area consists of interbedded sandstone, mudstone, claystone and limestone; some beds are hematitic and most are intensely weathered. The critical fossils are the brachiopod Eccentricosta sp. cf. E. jerseyensis (Weller, 1900) and the ostracode Welleriopsis? sp. aff. W.? pustulosa Berdan, 1972. The Eccentricosta beds at Sparks Gap and Clear Branch Gap are assigned to the Red Mountain because they are lithologically similar to lower beds in the formation. Thus the youngest part of the Red Mountain Formation in the Birmingham area is of Late Silurian, Pridolian, age. At Sparks Gap, underlying beds yielded Late Silurian corals that are not assigned to a faunal zone.

Well-preserved silicified sponges have been recovered from the Upper Permian Changxing Formation at Huangnitang in western Hubei province. The new species Cystauletes grossa and Cystothalamia irregulara are associated with Cystothalamia sp., Colospongia salinaria irregularis Zhang, 1983, Sollasia ostiolata Steinmann, 1882, Virgola? osiensis (de Gregorio, 1930), a questionable inozoan species, and a form questionably referred to the genus Hikorodium? sp. These sponges were detrital fragments that accumulated at the toe of the forereef, at the margin of slope fades and basin fades, at Huangnitang. Amblysiphonella vesiculosa minima Zhang, 1983, is represented in the collections from the Upper Permian Heshan Formation at the village of Guwu, near Heshan City in central Guangxi. Heshan beds that produced the silicified sponges are of Wujiapingian age and accumulated on a normal-marine, shallow-water carbonate platform, or in skeletal shoals within the carbonate platform, and represent a level-bottom community.

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.

We describe a partial dyrosaurid skeleton recently prepared out of a limestone block discovered in the 1930s from Danian strata along the Atlantic coast of Senegal. The specimen, from a single individual, comprises nicely preserved elements of the appendicular and axial skeleton from the abdominal and sacral region, which enables us to refine our knowledge on some postcranial characteristics of the Dyrosauridae. Although Dyrosauridae are abundant in early Eocene deposits of North Africa, the present discovery in the Danian of Senegal fills a patchier record early after the K/Pg boundary and provides an important comparative data point with the few other Danian dyrosaurid records such as Atlantosuchus from nearby Morocco or Guarinisuchus and Hyposaurus from Brazil and the USA, respectively.

Two new species of Eomyelodactylus, E. sparteus and E. uniformis, are described from the Lower Silurian of New York. Macnamaratylus murrayi Bolton from the Lower Silurian of Ontario, Canada, is redescribed and assigned to Eomyelodactylus. Together, these species permit detailed description of this poorly known myelodactylid genus.

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.

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.

Collections of four Ordovician bryozoan species from habitats of differing levels of taxonomic diversity were examined in order to assess the effect of environmental conditions on intraspecific and interspecific morphologic patterns. Up to 20 morphometric characteristics were measured for each species from populations in both high-diversity and low-diversity settings. Character means and the levels of character variability differ between populations in different diversity zones. Across species, mean character values differ significantly in 41 percent of the total comparisons, permitting intraspecific and interspecific multivariate discrimination of populations from the two diversity zones.

The partitioning of clonal morphologic variability into within-colony (nonheritable) and among-colony (potentially heritable) components reveals that habitat conditions favoring high diversities appear to promote a greater proportion of potentially heritable genetic variation both within- and among-species than do low-diversity settings wherein a larger percentage of variation is ecophenotypic, or nonheritable, plasticity. Although the actual percentages vary from species to species, this pattern is obtained for representatives of four different trepostome bryozoan families and therefore is robust. Variability of this sort, if unrecognized, could lead to taxonomic oversplitting along ecologic gradients. These local, facultative adjustments to environmental conditions may be indicative of processes involved in the reactions of populations to selective pressures.

Analyses such as this, coupled with examinations of character covariances, may permit the recognition not only of environmentally-induced morphologic plasticity and the proportions of potentially heritable and nonheritable variability, but also provide evidence for intraspecific changes in the rates and timing of developmental events (i.e., across-population or facultative heterochrony).

The Upper Chesterian Pitkin Formation of the Ozark Dome region contains a large and diverse, yet highly endemic, coral fauna consisting of 10 genera of rugose corals and three of tabulate corals. Coral distribution within the formation is affected by stratigraphic, paleoecologic, and possibly paleogeographic controls. Although it is impossible at this time to fully evaluate the importance of stratigraphic controls on the coral distribution, the occurrence of two types of carbonate bioherms within the formation provides substantial paleoecologic control on the distribution of certain corals. Despite the high endemism and facies restriction, the coral fauna has proven to be biostratigraphically sensitive, correlating with middle and upper Chesterian coral zones in the Western Interior Province of North America. Among the Pitkin corals herein described are the new genera: Lesliella n. gen. (L. amplexa n. sp., type species) and Parvaxon n. gen. (P. minutum n. sp., type species). Other newly described species are: Amplexizaphrentis browni n. sp., Barytichisma clubinei n. sp., B. ozarkana n. sp., and Leonardophyllum arkansanum n. sp., which represents the first reported occurrence of the genus in strata below the Pennsylvanian boundary.

Four new species of the methane seep-inhabiting kalenterid bivalve genus Caspiconcha Kelly in Kelly et al., 2000 are described: Caspiconcha basquensis from the late Albian of northern Spain, C. yubariensis from the late Albian of northern Japan, C. raukumaraensis from the late Albian to mid-Cenomanian of New Zealand, and C. lastsamurai from the Campanian of northern Japan. The earliest confirmed record of the genus is known from the latest Jurassic. It reached its maximum diversity in the Albian and declined in diversity and abundance through the Late Cretaceous. The youngest species, C. lastsamurai, is currently known from a single specimen only.

UUID: http://zoobank.org/2f84cfd3-216c-4f1b-8c9f-c808a47f7aaa

A new calappid crab, Prehepatus werneri n. sp., is described from the Upper Maastrichtian of Limburg, The Netherlands. This species represents the first European and youngest known member of the genus. The appearance of this species seems to correspond with an increasing Tethyan influence in the type-Maastrichtian area.

Two taxa of the Late Carboniferous and four species of the Early Permian terrestrial snails have been found in the Late Paleozoic continental molasse sediments of the Upper Silesian-Cracow Upland (Southern Poland). Discovery of Anthracopupa ohioensis and Protodiscus priscus indicates that, besides in North America, they occurred also in the European part of the Pangea supercontinent. According to the general sedimentary facies context and the accompanying floral and faunal assemblages, the gastropods lived in swamp environments, including a topogenous fen.

Membranous phylloid algae of the late Paleozoic have commonly been identified as Anchicodium Johnson, whereas the genus was originally described as being cylindrical and branched, much like modern Codium. The holotypes cannot be located, but examination of one lectotype specimen and neotypic thin sections from material from several of Johnson's original collection sites indicates that the original descriptions were valid.

Trilobites are a relatively rare faunal component in Carboniferous marine strata of the north-central Appalachian Basin. Three of the seven trilobite species known from the Lower Mississippian Waverly Group of Ohio, Griffithidella waverlyensis Hessler, Paladin marginatus (Hyde), and Brachymetopus nodosus Wilson, are monotypic and are known only from the type material. More commonly occurring species include Proetus (Pudoproetus) missouriensis (Shumard) and Breviphillipsia sampsoni (Vogdes), which are present in the Wooster and Meadville Shales and Byers Sandstone. The rare species, Australosutura lodiensis (Meek) and Piltonia eurybathrea (Hessler), are found most commonly in the Wooster and Meadville Shales. At least two species are present in Upper Mississippian strata. Paladin chesterensis (Weller) is found in most Upper Mississippian marine units and ranges through most of the Chesterian. Paladin cf. P. pyriformus Chamberlain is present in a single horizon in the lower Mauch Chunk (lower Chesterian) in southwestern Pennsylvania. Five trilobite species are present in Pennsylvanian strata. Sevillia trinucleata (Herrick) and Sevillia sevillensis Weller are present in upper Atokan and lower Desmoinesian strata of the Pottsville Group of Ohio. Ameura missouriensis (Shumard) first occurs in the Lower Mercer marine horizon (upper Atokan) and ranges to the Ames (Virgilian) marine unit. Ditomopyge scitula (Meek and Worthen), the most pervasive Pennsylvanian trilobite species, ranges from the Lower Mercer (upper Atokan) marine interval into the Portersville (Missourian) marine interval. Ditomopyge decurtata (Gheyselinck) is known only from the Ames marine interval (Virgilian), but may be present in higher marine zones.

Holmiids are a major component of the trilobite fauna in the middle part of the Montezuman Stage, the lowermost stage of the Cambrian of Laurentia with a continuous trilobite record. They are less common in the upper Montezuman where nevadiids predominate and other trilobite families appear. New material from western Nevada allows a revision of these holmiids. Palmettaspis parallela Fritz, 1995 and Palmettaspis cometes (Fritz, 1995) are assigned to a new genus, Montezumaspis, based primarily on thoracic characters, including a prominent axial spine on the thorax. A second new genus, Grandinasus, is based on Esmeraldina argenta (Walcott, 1910), in which the L3 lobe is incorporated in an expanded anterior lobe (LA) of the glabella. New species described are Esmeraldina elliptica, Grandinasus auricampus, G. patulus, Holmiella falx, and H. millerensis. The Laurentian taxa appear to be more primitive than the holmiids of Baltica by having simple, unfurrowed ocular lobes that are separated from the LA by an axial furrow. Three informal biofacies are suggested with a holmiid-dominated biofacies in a deep subtidal dysoxic environment, and two nevadiid-dominated biofacies in shallower subtidal environments.

Thin sections and acetate peels of the sediment within, and adhering to the outsides of, tests of Late Eocene echinoids from the southeastern United States have proven to be useful checks on inferences from test morphology concerning substrate preference. Previous characterizations of species' sediment preferences have concentrated primarily on the functional morphology of spatangoids, and relied particularly heavily upon Recent relatives of nonspatangoids. Reassessment of the preferences of spatangoids has led to a few discrepancies between interpretations herein and those of previous workers. In addition, this study attempts a more thorough assessment of functional morphology of nonspatangoid irregular echinoids than has previously been tried.

Carbonate sand-dwelling species from the Ocala Limestone (thin sections are clean grainstones) include Oligopygus, Echinolampas, Rhyncholampas, fibulariids, Durhamella, Neolaganum, Agassizia, Macropneustes, some species of Plagiobrissus and Periarchus, and most species of Eupatagus. All these have been interpreted previously as preferring clean sand. Species that preferred, or at least tolerated, significant carbonate mud in the substrate (thin sections are poorly washed grainstones and packstones) include all the regular echinoids and the irregular echinoids Schizaster, Ditremaster, Brissopsis, Brissopatagus, Amblypygus, Eurhodia, Weisbordella, Wythella, Paraster, some species of Periarchus and Plagiobrissus, and perhaps some species of Eupatagus. The last seven of these have previously been interpreted as sand-dwellers.

In general, species preferring mud-rich sands are found in the upper Ocala of peninsular Florida and in the middle to upper Ocala equivalents in the rest of the Gulf Coast. Sand-dwellers are most often found in the lower Ocala strata of both regions and up into the middle Ocala in Florida. These generalizations are consistent with existing paleoenvironmental models for the region.

A growth series of Stringocephalus gubiensis, described here, reveals that the cardinal process of Stringocephalus originated from a bilobate structure, and the growth of its dorsal median septum is highly related to cardinal process development. From this observation we conclude that Kaplex is, structurally and temporally, a suitable ancestor for Stringocephalus, with Bornhardtina ancestral to Kaplex. Subfamilial classification of the family Stringocephalidae is revised based on the presence or absence of median septa and the nature of hinge plates as well as on cardinal process formation. The Kaplexinae and Omoloninae are proposed as new subfamilies, with the Kaplexinae, including Kaplex and Erectocephalus, and the Omoloninae, including Omolonia, Kumbella, and Hemistringocephalus. Morphologic study of South China and Western Canadian Stringocephalus reveals that late forms of the genus tend to have a higher dorsal septum and more complex cardinal process than the early forms. In view of functional morphology, these trends reflect functional perfection of the cardinal process build-up and the lever system for improving the efficiency of opening and closing the shell.