A large sample of excellently preserved ammonites from concretions concentrated at a single horizon near the base of the Macdougall Point Member of the Christopher Formation (Aptian–Albian age; Early Cretaceous) is the basis for recognizing a new species of the boreal ammonite genus Pseudogastroplites (P. draconensis). The dimorphic nature of the genus is established, two variants are recognized (P. draconensis var. robusta and P. draconensis var. gracile), and the generic diagnosis is emended. Retention of the genus Pseudogastroplites Jeletzky, 1980 as distinct from Gastroplites McLearn, 1930 is proposed. The concretions also yield Pseudopulchellia flexicostata (Imlay, 1961), inoceramid bivalves, fish remains, and a palynological flora, and are dated as late middle Albian.

The new dragonfly family Austroperilestidae n. fam. based on Austroperilestes hunco n. gen. and sp. is erected from early Eocene of Patagonia (Argentina). Its phylogenetic relationships within the Zygoptera (sensu Bechly, 1996) are discussed. The new family seems to be related to Perilestidae, with a Neotropical and Afrotropical recent distribution.

Harpactocarcinus punctulatus istriensis Bachmayer and Nosan, 1959 is elevated to species level. Analysis of the larger foraminiferans associated with specimens of H. istriensis suggests a habitat preference for off-shore, clear, shelf environments below fair-weather wave base and an age of early to middle Lutetian (Eocene). A review of the paleoenvironmental indicators for nearly all species within the genera referred to the Zanthopsidae Via, 1959 suggests that all exhibit similar habitat preferences. Description of the paleoenvironmental preference for an entire extinct decapod family has not before been possible.

Gypidula was a common pentameride brachiopod in the Silurian and Devonian periods and its oldest-known form, Gypidula akimiskiformis new species, occurs as a common component of a distinct Gypidula Association of the rich and diverse reef-dwelling brachiopod fauna in the Lower Silurian (upper Telychian) Attawapiskat Formation of the Hudson Bay Basin. This pioneer species has a high degree of morphological plasticity, with several infraspecific variations significant for the study of gypiduloid taxonomy and early evolution: 1) the sparsely costate shells may have strong to faint medial ribs, with some shells being quasi-smooth and 2) the inner hinge plates are commonly basomedially inclined toward the dorsal valve floor (not united to form a cruralium), but may also be subparallel or slightly basolaterally divergent toward the valve floor (similar to those in Clorinda). This implies that the basomedially inclined inner hinge plates were not a stable character at the initial stage of evolution of Gypidula during the late Telychian. Another gypiduloid from the Attawapiskat Formation, Erilevigatella euthylomata new genus and species, is characterized by a shell lacking fold or sulcus but having Clorinda-type, basolaterally divergent inner hinge plates and double-flanged crura. Compared to Levigatella, which has been regarded as an intermediate between Clorinda and Gypidula because of its Gypidula-type dorsal sulcus and Clorinda-type inner hinge plates, the rectimarginate shells of Erilevigatella make the distinction between Clorinda and Gypidula even more blurred at the early stage of their evolution.

Macgeea is a cosmopolitan genus of Devonian rugose corals that includes numerous, generally highly variable, species. Because of its wide skeletal variation and additional trabecular dilation it is difficult to recognize taxonomically relevant characters and to separate those from ecologically induced modifications. The high variability is probably related to radiations following phases of sea level rise and is connected to bioevents. Length of major septa in ontogenetic stages allows a separation of different populations within the Macgeea dubia species group. However, it remains questionable if septal length is a reliable taxonomic character, indicating a phylogenetic trend, or if it is subject to large individual variability. By revising Macgeea dubia, we reveal its synonymy with Macgeea heterophylloides sensu Birenheide. In addition, Macgeea recta (type species of Pexiphyllum Walther, 1929) is discussed as an insufficiently defined taxon of problematic status. Macgeea crassiseptata n. sp. is also described from the Late Givetian of Morocco.

The erection of the new pseudocolumellate genus Baculophyllum with type species Pexiphyllum ultimum Walther, 1929 requires a comparison with Protomacgeea from Poland and Australia as well as a phylogenetic discussion of the solitary Phillipsastreidae. The new genus most probably belongs to a separate lineage of the Upper Devonian Macgeea group but could also be considered as a descendant of the Australian Lower Devonian columellate solitary phillipsastreid species group, that has not yet been recorded from the Middle Devonian. Because of large stratigraphic gaps between the occurrences of both genera, preference is given to the interpretation of a development of polycronomorph taxa (homeomorphic taxa living at a different time) not belonging to a single lineage. This shows again the significance of stratigraphic age when comparing similar-looking taxa, which should be considered in any phylogenetic reconstruction.

Brachiopods are common in the lower and middle parts of the early Mississippian (Osagean) Vicente Guerrero Formation that is mainly a fine-grained quartz arenite found in the Ciudad Victoria area, Tamaulipas, northeastern México. This shallow marine brachiopod fauna includes several spire-bearers: Lamellosathyris lamellosa, Cleiothyridina cf. tenuilineata, Camarophorella sp., Alispirifer tamaulipensis n. sp., Tylothyris? sp., Torynifer pseudolineatus, Syringothyris cf. typa, Syringothyris? sp., and Punctospirifer sp. Similar assemblages have been found in Osagean rocks of the Santiago Formation, Oaxaca, southeastern México, and in several coeval formations in the USA: Arizona, Arkansas, Illinois, Ohio, and Texas. North American biogeographic affinities are suggested for these Mississippian faunas of northeastern México. These contrast markedly with the Late Silurian situation, where the Tamaulipas material has Old World Realm, rather than North American, biogeographic affinities. This supports the interpretation that northeastern México was an integral part of North America by the Mississippian, but not in the Late Silurian.

Reconsideration of the nature of zooids in trepostomate Bryozoa defines them as physically connected and asexually replicated colony members that housed systems of organs necessary to perform vital functions for the colonies. Zooids known to contain organs in trepostomes are limited to autozooids, the requisite feeding and sexual units, and polymorphs, including macrozooids and two rare zooids of unknown function. Other colony structures are extrazooidal and remain outside zooidal boundaries throughout colony life. They include the commonly occurring mesopores, exilapores, and styles. This two-part morphologic division of colonies reveals two correlated functions. The essential autozooids dominated the growth patterns and physiology of trepostome colonies; the extrazooidal parts grew concurrently and passively to connect autozooids and to support and strengthen colonies.

A new synziphosurine (Chelicerata: Xiphosura) is described from the Late Llandovery (Silurian) Konservat-Lagerstätte of Waukesha, Wisconsin, USA. Venustulus waukeshaensis n.gen. and sp. is characterized by a semicircular carapace with a slightly procurved posterior margin lacking genal spines and an opisthosoma composed of 10 freely articulating segments, divided into a preabdomen of seven segments with blunt pleurae and a postabdomen of three segments lacking pleurae. The tail spine is short and styliform. This is the earliest known unequivocal synziphosurine, extending their fossil record from the Wenlock to the Llandovery, and only the second species to be described with prosomal appendages; the presence of six pairs (a pair of chelicerae and five pairs of walking legs) contrasts with the seven in the synziphosurine Weinbergina opitzi, but is comparable to the number in modern horseshoe crabs. V. waukeshaensis n. gen. and sp. is not assigned to a family here pending a wider revision, but it bears most resemblance to the Weinberginidae.

The Topazan Stage is proposed for the interval between the Delamaran Stage and the originally proposed base of the Marjuman Stage. The proposed stratotype of the lower boundary of the Topazan Stage occurs 2.6 m above the base of the upper shale member of the Chisholm Formation, Drum Mountains, Utah. This boundary occurs within a shale sequence and is marked by the first appearance of Proehmaniella basilica, which also coincides with the disappearance of the common corynexochid Glossopleura. This faunal turnover can be recognized in stratigraphic sections in western North America and Tennessee, but cannot be recognized outside of Laurentia. The base of the overlying Marjuman Stage is restored to its originally proposed boundary, the FAD of Ptychagnostus atavus.

Seven genera and eight species of lingulate brachiopods were recovered from the House Limestone and lower Fillmore Formation, Ibex area, Utah, USA. These strata are assigned to the upper Skullrockian Stage and lower Stairsian Stage of the Ibexian Series (Iapetognathus Conodont Zone to Low Diversity Interval) and are correlated with the Tremadocian Series of the Acado–Baltic Faunal Province. The fauna includes two new linguloid species, Spinilingula prisca and Wahwahlingula sevierensis, one new siphonotretoid species, Schizambon obtusus, and two new acrotretoid species, Eurytreta fillmorensis and Ottenbyella ibexiana. The last species is the first record of the genus in North America and suggests a correlation of the basal Fillmore Formation with the Ceratopyge Limestone in Sweden. A Siphonobolus? covered by long hollow spines may be one of the oldest siphonotretides with such ornament. This fauna and those described previously from older Utah strata document the biodiversification of the Cambrian–Ordovician lingulate brachiopods and demonstrate their potential for regional and intercontinental correlation.

Pleurojulid millipedes, known since the turn of the last century to be relatively abundant in the Westphalian D (Carboniferous: Pennsylvanian) Gaskohl of Nýřany, Czech Republic, are here also identified as an important component of the Pennsylvanian (Westphalian D) Mazon Creek millipede fauna preserved in ironstone nodules. Pleurojulids reach lengths approaching 10 cm, have as many as 69 body segments, medium-sized heads, and large ocellaria with upwards of 40 ocelli. Pleurojulids have previously been interpreted as having either a juliform-like or a colobognathan-like trunk-ring architecture. In order to distinguish between these two hypotheses, almost all pleurojulid specimens in museum collections were surveyed to document the deformation pattern of exoskeletal elements to aid in reconstruction of the trunk-ring architecture. The Nýřany specimens are completely flattened while the Mazon Creek specimens retain a degree of three-dimensionality. In order to assess how trunk-ring architecture controls patterns of deformation, a variety of extant millipedes were experimentally compressed. The distribution of exoskeletal elements in pleurojulid fossils was most similar to that seen in compressed extant polyzoniid millipedes. Based on the available evidence, pleurojulid trunk-ring architecture is reconstructed as semicircular in cross section, consisting of arched diplotergites, free pleurites firmly articulated to the lateral margins of the tergites and held in a near horizontal position, and free sternites. Pleurojulida are hypothesized to be basal helminthomorph, the sister group to Colobognatha, though inclusion in Helminthomorpha is equivocal. The taxonomy of previously described pleurojulid millipedes from Nýřany is revised and newly recognized specimens from Mazon Creek specimens are described. Two genera are recognized within the new order Pleurojulida: Pleurojulus and Isojulus. Two species of Pleurojulus are recognized: P. biornatus and P. levis. Pleurojulus aculeatus and P. pinguis are synonymized with P. levis. Only one species of Isojulus, I. constans, is recognized with I. setipes, I. marginatus synonymized with it along with Pleurojulus longipes and P. falcifer.

A newly discovered Late Ordovician (early Ashgill) brachiopod assemblage from the Linhsiang Formation in the middle part of the Yangtze Platform, South China, bridges the paleobiogeographical gap between the early Ashgill Foliomena-bearing associations known previously from the upper and the lower parts of the Yangtze Platform. Characterized by minute shells in calcareous to siliciclastic mudstones, the fauna contains 13 brachiopod genera, of which two plectambonitoids are new: Hadroskolos and Jingshanella. Cluster and principal component analyses, based on 29 global occurrences of the Foliomena fauna in Laurentia, Avalonia, Kazakhstan, Baltica, Sardinia, Bohemia, Sibumasu, North China, and South China, revealed broad trends of spatial and temporal faunal differentiation in terms of taxonomic compositions. The analyses demonstrate for the first time that early Foliomena-bearing associations of Caradoc age occupied primarily deepwater (distal shelf) environments with a siliciclastic or calcareous mud substrate. The fauna attained its widest paleogeographical distribution and paleoecological range (midshelf to shelf margin settings) during the early Ashgill.

The Williams Fork Formation preserves a diverse dinosaur fauna containing at least nine saurischian and five ornithischian species. Among the dinosaur specimens recovered is a partial ceratopsian skull (SDMNH 43470) referable to the ceratopsid subfamily Chasmosaurinae (Diem, 1999). Chasmosaurines, or long-frilled ceratopsians, existed throughout western North America during the Campanian and Maastrichtian (Judithian, Edmontonian, and Lancian). Recent discoveries have renewed debate over the phylogenetic relationships and biogeographic history among the chasmosaurines (Forster et al., 1993; Lehman, 1996; Holmes et al., 2001).

A jawed polychaete fauna from the upper 30 m of the Upper Ordovician Sylvan Shale (Richmondian, Ashgill) of Oklahoma is described, based on recovered scolecodonts (polychaete jaws). The fauna includes members of six families: Paulinitidae, Ramphoprionidae, Polychaetaspidae, Atraktoprionidae, Hadoprionidae, and Kalloprionidae. Ten species are identified and one new paulinitid species, Kettnerites (Aeolus) sylvanensis, dominates. The low-abundance and relatively low-diversity Sylvan Shale fauna differs from approximately coeval ones of both Laurentia and Baltica, particularly by its high relative frequency of paulinitids. The scolecodonts are associated with chitinozoans, as well as some enigmatic organic-walled microfossils. Conodonts are extremely rare, with Plectodina tenuis, Amorphognathus sp., and Dapsilodus sp. identified.

Conella, Eurypyrene, and Parametaria are three taxa of columbellid neogastropods native to the Neogene American tropics whose monophyly and relationships have traditionally been confused. The primary objective of this study is to reconstruct the phylogenetic relationships of the tropical American species in these genera, to evaluate their monophyly, and to establish their constituencies. Parsimony-based phylogenetic analysis was used to generate phylogenetic topologies, after which the shortest trees were evaluated to minimize stratigraphic debt using a stratigraphic character added to the data set. The morphologically most parsimonious topologies are well resolved but the main clades are not well supported. Stratocladistic evaluation of the most parsimonious trees resulted in four morphologically and stratigraphically shortest trees. Overall, the resultant trees suggest that Conella and Eurypyrene are monophyletic with minor changes to their traditional constituency, but the resulting trees do not support monophyly or constituency of Parametaria, except in a very restricted sense, or as a paraphyletic group including one or more other traditional genera.

The Khabarovsk Complex, a Jurassic accretionary complex distributed in and around the Khabarovsk city area, Far East Russia, comprises mélange and schist facies. From the review of previous studies including Russian papers, the lithology and age of the constituent rocks of the mélange facies can be summarized as follows: Upper Paleozoic basic volcanic rocks, mainly pillow lava, and altered gabbro, Upper Carboniferous to Upper Permian fusulinoidean-bearing limestone associated with tuff, Lower and Middle Jurassic siliceous mudstone, Upper Jurassic tuffaceous mudstone, uppermost Jurassic carbonate concretions embedded in mudstone, and age-unknown sandstone. Newly found sequences of limestone-chert and of basalt-chert in the mélange facies crop out along the Amur River in the Khabarovsk city area. A chert sample of the limestone-chert sequence contains Albaillella aff. asymmetrica and Pseudoalbaillella aff. lomentaria, and a chert sample of the basalt-chert sequence includes Follicucullus monacanthus, Follicucullus porrectus, and Pseudoalbaillella cf. yanaharaensis. The radiolarian assemblages from the limestone-chert and basalt-chert sequences have a maximum age of middle Early Permian and late Middle Permian, respectively, overlapping the time of deposition of the fusulinoidean-bearing limestone. The co-occurrence of chert and limestone indicates that the fusulinoidean-bearing limestone was formed on a basaltic topographic high in a pelagic ocean whereas the radiolarians accumulated in a deeper part. Limestone debris occasionally flowed into the depositional site of the radiolarian chert. Although the Khabarovsk Complex was simply considered as a northern extension of the Mino-Tamba Belt of the Inner Zone of southwest Japan, we propose a new correlation based on the lithologic associations. The mélange facies of the Khabarovsk Complex is correlative with one of the Kasugano, Funabuseyama, Nabi, and Yabuhara Formations in the Mino-Tamba Belt, whereas the schist facies is correlative with the Hikami Formation of the Ultra-Tamba Belt.

A single bed at the base of the Jordan Sandstone in a road cut at Arcadia, Wisconsin, yielded an undescribed Late Sunwaptan (Saukia Zone) trilobite fauna that includes at least four species from the families Dikelocephalidae Miller, 1889 and Eurekiidae Hupé, 1953. Arcadiaspis bispinata n. gen. and sp. is a distinctive eurekiid that is characterized by paired occipital and thoracic axial spines, long genal spines, and a nonspinose pygidial margin. Other genera present are the dikelocephalids, Dikelocephalus Owen, 1852 and Calvinella Walcott, 1914, and the eurekiid, Eurekia Walcott, 1916. Type material of Calvinella spiniger (Hall, 1863) is illustrated photographically for the first time. A new eurekiid species, Corbinia burkhalteri from the Fort Sill Formation, Oklahoma, is also described.

This paper describes 19 brachiopod species (including six indeterminate species) in 15 genera and one indeterminate genus from the basal Itaituba Formation at the Caima Quarry 1 section of Itaituba, Amazon Basin, Brazil. The faunal correlations of the brachiopods and the associated fusulinids and conodonts indicate a late Chesterian (late Serpukhovian) age for the described fauna, therefore confirming for the first time the presence of uppermost Mississippian rocks in the Amazon Basin. A new species, Composita caimaensis, is created, and two species, Inflatia cf. gracilis and Marginovatia cf. catinulus, are described for the first time from the Amazon Basin. The Amazon brachiopods appear to be of strong affinity with coeval faunas of the North American midcontinent.

Previously unstudied and earlier-known specimens have revealed the wide cephalic doublure and median ventral suture in Stenopilus; the hypostome is unknown but was probably natant. The cranidium of S. pronus differs from that of the type species S. intermedius in its greater length and convexity; the pygidium is known from rare complete specimens. These two species are present in Quebec, Newfoundland, and Vermont. They are differentiated from Leiocoryphe, which also had a highly effaced cephalon. Relationships remain problematic between these two genera and others currently placed in Plethopeltidae. An enrolled specimen of S. pronus is refigured and the anatomy and mode of life considered as that of a vagrant benthic animal rather than one that lived in a burrow as previously thought.