An exceptionally large skeleton of Pentaceratops sternbergi (Ornithischia:Ceratopsia) provides for the first time an accurate impression of the body proportions in this horned dinosaur. This is the only known specimen with a skull associated with most of the postcranial skeleton. The restored skull is nearly three meters in length and is thus the largest of any ceratopsian and the largest skull thus far known in any terrestrial vertebrate. The elongate rostrum, elaborate premaxillary structure, and complex frontal and cornual sinuses demonstrate a high level of intraspecific variability in these features. Such features are therefore likely not useful in providing species-level discrimination in other chasmosaurines. The function of the intricate chasmosaurine premaxillary narial structures is probably associated with an advanced level of herbivory.

The occurrence of freshwater turtle remains in the late Miocene lignites of southern Tuscany (Montebamboli and Casteani, Italy) has been known since the nineteenth century. Three chelonian species were recognized by Ristori in 1891: Emys depressa, E. campanii, and E. parva. Revision of their type material, together with the study of new fossils from a different but correlated locality, Pian Calcinaio (Scansano), allows one to state that they can be referred to the genus Mauremys and that they belong to one single species. the new combination M. campanii (Ristori, 1891) is here proposed. Phylogenetic analysis indicates that M. campanii is closely related to the modern post-Miocene group of Mauremys species and shows a sister-group relationship with the Plio-Pleistocene M. gaudryi. the remains of M. campanii come from an insular setting which progressively lost its endemic mammal fauna, defined as the Oreopithecus Zone Fauna, enabling us to compare the pattern of survival of the chelonians with that of the mammals. in contrast to the radical turnover suffered by mammals, softshell turtles (Trionyx sp.) and terrapins (M. campanii) are present both in the pre-Messinian V1-V2 and Messinian V3 assemblages. Terrestrial tortoises (Testudo amiatae Pantanelli, 1893, Testudo s.l.) show a different pattern, because they appear only in the V3 assemblage, possibly because they apparently dispersed into Italy as recently as the Messinian. M. campanii represents the southernmost evidence of the genus Mauremys in the uppermost Miocene of Europe, filling a gap in the palaeogeographic and chronological distribution of this genus.

New collections of trilobites from the type section of the Parahio Formation in the Parahio Valley, Spiti, and from the Parahio, Karsha, and Kurgiakh formations in the Zanskar Valley, permit biozonation based on material precisely located within measured stratigraphic sections. Specimens preserved in limestone with mild tectonic deformation clarify the features of several Himalayan taxa known previously only from severely deformed specimens preserved in shale. A total of 75 trilobite taxa from the Cambrian of Spiti and Zanskar can be referred, questionably at least, at the generic level or below, and 61 of these are present in our new collections. This new material is assigned with confidence to 29 existing species, and to 12 new species. Three new genera, Haydenaspis, Bhargavia, and Himalisania, are established; new species include Haydenaspis parvatya, Prozacanthoides lahiri, Probowmania bhatti, Xingrenaspis parthiva, X. shyamalae, Bhargavia prakritika, Kaotaia prachina, Gunnia smithi, Sudanamonocarina sinindica, Proasaphiscus simoni, Koldinia odelli, and Torifera jelli. Ten additional Himalayan forms are assigned at the generic level only, and another 11 are questionably assigned to genera or species. The zonation proposed includes 6 zones and 3 levels, including the Haydenaspis parvatya level, the Oryctocephalus indicus level, the Kaotaia prachina Zone, the Paramecephalus defossus Zone, the Oryctocephalus salteri Zone, the Iranoleesia butes level, the Sudanomocarina sinindica Zone, the Lejopyge acantha Zone, and the Proagnostus bulbus Zone. The sections span from the upper part of the informal Stage 4, Series 2 of the Cambrian System, about 511 Ma old, to the Proagnostus bulbus zone of the Guzhangian Stage near the top of Series 3, dated at about 501 Ma. This time interval is represented by about 2000 m of section, which is thick compared to similar intervals elsewhere and is consistent with high rates of sedimentation along the Himalayan margin at the time. The fauna resembles others from equatorial peri-Gondwanaland, with closest similarity to that of South China. It also bears strong affinity to the North China fauna. Juvenile trilobites are described for the first time from India. A new Chinese species, Monanocephalus liquani, is also described.

Hadoprion cervicornis (Hinde, 1879) from the Upper Ordovician and Lower Silurian (Cincinnatian to Medinian) replaces four generic and eight specific names: Arabellites cervicornis, A. aciculatus, Oenonites acinaces, Ildraites horridus, I. laeohorridus, I. cervicornis, Nereidavus hamus, and N. alatus. This example illustrates the advantages of a nomenclature in accordance with the ICZN. The authors reject the use of parataxonomy for fossil jawed polychaetes.

New Ediacaran fossil finds at Sekwi Brook occur in lower shoreface to offshore transition beds at the top of the Blueflower Formation, which are the most shallow-water facies and the youngest strata in which Ediacara-type fossils have been described from the Mackenzie Mountains of NW Canada. Newly discovered Ediacaran body fossils include two new tubular genera: Sekwitubulus annulatus new genus new species was a mm-diameter rigid annulated tube that was rooted to the sea bottom by a holdfast; Annulatubus flexuosus n. gen. n. sp. was a cm-diameter, flexible annulated tube. In conjunction with previously described large attachment discs representing the form-genus Aspidella and a single specimen of the dickinsonid Windermeria, these fossils define an assemblage that differs markedly from the rangeomorph-dominated deeper-water and older assemblages lower in the same section at Sekwi Brook. In contrast, trace fossils show little change upwards through the Blueflower Formation, at least in part reflecting their origin by microbial grazers on mats that formed during low-energy periods in both deep- and shallow-water environments. This implies that the stratigraphic succession of Ediacaran fossils in NW Canada and probably globally represents both evolutionary changes with age and the paleoecology of specific depositional settings.

Dolabrosaurus aquatilis n. gen. and sp., a small amphibious or aquatic reptile from the Upper Triassic Chinle Formation of north-central New Mexico, is described on the basis of portions of the vertebral column and partial fore- and hindlimbs of a single specimen. Comparison with other Triassic reptiles indicates that D. aquatilis is most closely related to Drepanosaurus unguicaudatus, a small, enigmatic lepidosauromorph from the Upper Triassic Zorzino Formation of the Italian Alps. Both species are assigned to a new family, Drepanosauridae, with Dolabrosaurus recognized as more primitive in some aspects of its vertebral and pedal morphology. The precise assignment of Drepanosauridae within the Lepidosauromorpha remains uncertain.

Upper Ordovician radiolarians are described from limestone within the Malongulli Formation in the Cliefden Caves area using revised systematics. Eight genera and 12 species are described, including the following four new species: Protoceratoikiscum crossingi, Haplotaeniatum ovatum, Haplotaeniatum prolatum, and Borisella dunhilli, and two new combinations, Borisella subulata and Haplotaeniatum spongium. All samples are dominated by Kalimnasphaera maculosa, B. subulata, and Palaeoephippium octaramosum with lesser abundances of Haplotaeniaum spp. and Inanigutta complanata, and rare occurrences of Protoceratoikicsum spp. The rare species Etymalbaillella yennienii is reported for the first time outside of China. The Malongulli Formation is upper Eastonian through lower Bolindian (Katian global stage) based on graptolite and conodont biostratigraphy. From a stratigraphic standpoint, the limestone intervals sampled appear to represent two or possibly three stratigraphically separate intervals within the Malongulli Formation. Conodonts recovered from Coppermine Creek, Angullong/Belubula, and Gleesons Creek localities occur in the lower and middle parts of the formation and fall within one conodont zone, the O. velicuspis Zone. The stratigraphic position of the limestone at the Sugarloaf Creek locality is higher, possibly as high as lower Bolindian, based on proximity to the top of the formation where Bolindian graptolites have been recovered. Despite the different stratigraphic positions of the limestones, the radiolarians contained within are essentially the same fauna, barring some differences in relative abundance in Haplotaeniatum and Palaeoephippium. The Malongulli fauna is discussed with respect to other Upper Ordovician faunas, most notably those from siliceous facies in the eastern Lachlan Orogen and from the Hanson Creek Formation of Nevada, U.S. The radiolarian species occur across different depositional environments and from a range of geographically widespread localities, which bodes well for them being recognized as biostratigraphically important faunal markers with correlation potential within the Katian.

Epibionts on specimens of Flexicalymene (Late Ordovician, Cincinnati Arch region, U.S.A.) that were encrusted while alive show an apparent preference for attachment along the relatively elevated sagittal axis of the exoskeleton (glabella, axial rings of thorax and pygidium) or the medial portion of the cephalic doublure. This site-specificity supports an interpretation of a semi-infaunal habit for this trilobite and may indicate a commensal relationship between the epizoan and host (e.g., epizoan bryozoans exploiting the trilobite exoskeleton as a hard substrate and perhaps benefitting from feeding currents generated by the trilobite). Epizoans are found only on larger individuals of this trilobite, suggesting a terminal molt stage for Flexicalymene.

Although the number of previously reported encrusted trilobites is small, a survey of the literature suggests the following hypotheses concerning the relationships between trilobite life habit and susceptibility to epizoan colonization: 1) infaunal (burrow dwelling) trilobites were generally free of epizoans; 2) a small proportion of shallow-burrowing (semi-infaunal or “ploughing”) trilobites were suitable hosts for epizoans, but the epizoans preferentially colonized the elevated or anterior portions of the exoskeleton; 3) epifaunal (and some pelagic?) trilobites were more susceptible to encrustation.

From the Middle Jurassic on, the Tethys basin opened westward; the existence of a Carribean corridor linking the European and Pacific realms now appears well supported by comparison of marine reptile assemblages (e.g., Gasparini and Fernández, 1997, 2005; Gasparini et al., 2000; Fernández and Iturralde-Vinent, 2000; Gasparini and Iturralde-Vinent, 2001, 2006; Gasparini et al., 2002). Marine transgression in Mexico began during the Callovian, as evidenced by the evaporites of the Minas Viejas Fm. However, microfossils and invertebrate assemblages indicate that the Mexican Gulf remained isolated from both the European Archipelago and the Pacific, at least temporarily, until the middle Berriasian; the Florida uplift and southward movement of Yucatan were proposed as possibly forming a barrier (Salvador et al., 1993; Adatte et al., 1994, 1996; Goldhammer, 1999; Goldhammer and Johnston, 2001; Gasparini and Iturralde-Vinent, 2006). After almost a decade of field work and examination of collections, the Late Jurassic marine reptile assemblage of north-east Mexico confirms the conclusions drawn from microfossils and invertebrates. Poorly diagnostic ichthyosaur remains, with various thalattosuchians, numerically dominate the assemblage. Sauropterygians are rare, mainly represented by large pliosaurids of unclear affinities, a few vertebrae attributed to elasmosaurids, and a unique cryptoclidid. Turtles are yet to be reported (Frey et al., 2002; Buchy et al., 2003, 2005b, 2006a–d; Buchy, 2007, 2008a, b; material currently under study).

In Ediacaran shallow-water dolomites of the Doushantuo Formation (ca. 570 Ma) of southern China, scarce phosphatized microfossils consisting of clusters of coil-like spheroids called Spiralicellula bulbifera and co-occurring spherical forms with helically arranged holes named Helicoforamina wenganica are interpreted to belong to the same taxon because both have a similar relative abundance and both, uniquely in the assemblage, exhibit a consistent dextral spiral feature—the oldest known fossil examples of fixed asymmetry. Thus, we interpret them as different stages of sexual and asexual life cycles in which the spiral structure was maintained throughout most of the developmental phases. While they can be placed with the acritarchs, we suggest they are a chlorophycean green alga, and like many Ediacaran macrofossils, may represent an extinct clade. This is compatible with the shoal-water marine depositional environment in which they lived, as it would have favored photosynthetic organisms over others kinds of encysting non-metazoan protists. This setting militates against their interpretation as putative embryos which has been put forward for a variety of forms co-occurring in the microfossil assemblage. The multiple affinities of the strikingly diverse biota remain far from resolved, but algal origins warrant further consideration.

The Middle Ordovician (Darriwilian) Winneshiek Lagerstätte of northeast Iowa is preserved in a meteorite crater. Besides conodonts, the fossils are dominated by arthropods, particularly eurypterids and phyllocarids. Here we describe the bivalved forms, which include at least seven different taxa. The small phyllocarid Ceratiocaris winneshiekensis, new species, is the most abundant; it is the oldest representative of the Ceratiocarididae. A single incomplete abdomen and telson bearing furcal rami is reminiscent of notostracan branchiopods but its affinities are unknown. Decoracaris hildebrandi, new genus and species, is a rare form with a shield that extends anteriorly into a swollen horn and reaches lengths of 9 cm: it may represent a thylacocephalan crustacean but this cannot be confirmed without soft parts. Iosuperstes collisionis, new genus and species, is represented by suboval valves 10–25 mm long: its affinities are unknown. A probable leperditicopid, which ranges in length from 8 to 18 mm, is commonly preserved in a ‘butterflied’ configuration. It does not preserve the scars and sinuses characteristic of three-dimensionally preserved leperditicopids from elsewhere. Finally the fauna includes at least three ostracods, including a palaeocope with a granular surface and relief similar to Lomatopisthia, and a smooth ?podocope. The Winneshiek fauna differs from those of other Ordovician Lagerstätten from restricted settings such as Airport Cove and William Lake in Manitoba (Katian) where, apart from ostracods, bivalved arthropods are absent, and Silurian examples such as Brandon Bridge (Telychian), which lacks eurypterids, and the Williamsville Member of the Bertie Formation (Pridoli) where conodont assemblages are absent.

Size increase in European Miocene Anchitherium was described early in the century. Increase in size, particularly of the teeth, was common to the middle and late Miocene Eurasian Anchitherium and North American Hypohippus, including Megahippus, over the whole Holarctic range of these anchitherines. In this paper, size trends are described and interpreted against the background of simultaneous climatic change.

Termites (order Isoptera) are highly eusocial members of the superorder Dictyoptera. Species generally live in large, highly organized colonies with morphologically specialized worker and gyne castes, and in some lineages a soldier caste also occurs. The termites play an essential ecological role in the decomposition and recycling of a nutritionally poor, highly resistant, but extremely abundant substance: lignocellulose. This digestion is aided by symbionts (either intestinal Protista in lower termites, or fungi or intestinal bacteria in higher termites). In addition, methane excretion from termites contributes 2%–5% of the partial pressure of this gas in the Earth's atmosphere (Sugimoto et al., 2000). Considering all of these factors it is easy to understand why the approximately 2,900 termite species are among the most significant insects in many ecosystems throughout the world.

A growth series is described for a new species of Ceratocara Ramsköld, 1991, C. argentina, from the Upper Ordovician (Caradoc) part of the Las Aguaditas Formation, near Jáchal in San Juan Province, Argentine Precordillera. Another new species of Ceratocara, C. shawi, is described from the Middle Ordovician (lower Chazy) Crown Point Formation of New York. A phylogenetic analysis is presented for these species, other well-known Ordovician species of Ceratocara, and some Ordovician species of Ceratocephala, with Ceratocephalina tridens Whittington, 1956, as outgroup. The analysis presented supports the monophyly of both Ceratocara and Ceratocephala Warder, 1838, their divergence having occurred by the middle Arenig. The ontogenies of the Ceratocara species from Argentina and New York, complete from protaspid to holaspid growth stages, are some of the best preserved odontopleurid ontogenies described to date. Material of Ceratocephala triacantheis Whittington and Evitt, 1954, from the Crown Point Formation of the Chazy Group of New York, is discriminated from that of Ceratocara shawi.

The midgut of a new specimen of Typhloesus wellsi (Melton and Scott) from the Bear Gulch Member (Namurian, Montana) contains a complete, well-preserved apparatus of Kladognathus Rexroad. The apparatus comprises 2 Pa, 2 Pb, 1 Sa, 4 Sb, 4 Sc, and 2 M elements. Kladognathus and Oulodus angulatus (Hinde) are the only members of the Prioniodinida of which complete, well-preserved bedding plane assemblages are known. The arrangement of elements in these assemblages suggests that the prioniodinid Bauplan was similar to that of ozarkodinids.

The Early Triassic vertebrate record from low paleolatitudes is spotty, which led to the notion of an ‘equatorial vertebrate eclipse’ during the Smithian. Here we present articulated ray-finned fishes (Actinopterygii), collected from the marine Lower Triassic Thaynes Group at three new localities in Elko County (Nevada, USA), which were deposited within the equatorial zone. From the Smithian of the Winecup Ranch, we describe two partial skulls of the predatory actinopterygian Birgeria (Birgeriidae), attributed to B. americana new species and Birgeria sp. Birgeria americana n. sp. is distinguished from other species by a less reduced operculogular series. With an estimated total length of 1.72–1.85m, it is among the largest birgeriids. We confirm that Birgeria encompasses species with either two or three rows of teeth on the maxilla and dentary, and suggest that species with three well-developed rows are restricted to the Early Triassic. From the latest Smithian of Palomino Ridge, we present a three-dimensional, partial skull of the longirostrine predator Saurichthys (Saurichthyidae). This and other occurrences indicate that saurichthyids were common in the western USA basin. From the early late Spathian of Crittenden Springs, we describe a posterior body portion (Actinopterygii indet.). This find is important given the paucity of Spathian osteichthyan sites. We provide a summary of Early Triassic vertebrate occurrences in the United States, concluding that vertebrate fossils remain largely unstudied. The presence of predatory vertebrates in subequatorial latitudes during the Smithian confirms that Early Triassic trophic chains were not shortened and contradicts the ‘equatorial vertebrate eclipse’.

New discoveries of the early Cambrian yiliangellinine trilobite Zhangshania typica Li and Zhang in Kunming preserve almost all instars from early postembryonic (protaspid) to mature (holaspid) phases in articulated state, in addition to mature specimens with antennae bearing paired spines on the basal articles. The ontogenetic series shows protarthrous development with some, but likely not all, early holaspid instars expressing additional pygidial segments, gradual rearward migration of the location of the longest pleural spines on the trunk segments, and striking positive allometry of the genal spines. It also reveals Parazhangshania sichuanensis Li and Zhang, 1990 to be the holaspid stage 3 of Z. typica, and therefore its junior synonym. This new find in the Hongjingshao Formation provides species-based regional correlation across the South China block and Z. typica may provide an important biostratigraphic marker for the base of the traditional Tsanglangpuan Stage.

Since the publication of Darwin (1859), the biological meaning of the Cambrian radiation has been debated. Most commentators agree, however, that the Cambrian radiation is fundamentally a time of major metazoan cladogenesis. In and of itself this does not necessarily mean that unique evolutionary processes operated during the Cambrian radiation. Phylogenetic analysis has been used to study the tempo of speciation during the radiation, and thus far there is no need to invoke special rules relating to the tempo of evolution. Instead, what seems unique about the Cambrian radiation is its place as an important episode in the history of life—that is, as the first major radiation of the Metazoa. Although the tempo of evolution during the Cambrian radiation may not have been uniquely high, there were largely unique tectonic events that transpired during the late Neoproterozoic and Early Cambrian, such as extensive cratonic fragmentation. Biogeographic analysis of Early Cambrian olenelloid trilobites reveals that these tectonic events powerfully influenced evolutionary and distributional patterns in this diverse and abundant trilobite group. This emphasizes the importance of physical earth history in generating evolutionary patterns. In the general study of macroevolutionary patterns and processes, earth history phenomena emerge as powerful forces influencing the history of life and provide insights into evolution that can best be inferred by paleontological data.

A limited fauna of relatively simple, thin-walled, hexactinellid sponges, including moderately coarse-textured, funnellike Hexactinella(?) conica new species, fine-textured, tubular to branched Hexactinella(?) tubula new species, fragments of delicate Eurete goederti(?) Rigby and Jenkins, 1983, and Farrea(?) species, has been found in the Oligocene Lincoln Creek Formation on Canyon River, in the southcentral part of the Olympic Peninsula, Washington. These sponges dominate a chemosynthetic invertebrate assemblage that included the gastropod Provanna antigua Squires, 1995; the polyplacophoran Leptochiton alveolus (Lovén, 1846), and radiolarians. Most of the sponges are preserved as silica in a localized cherty and botryoidal, calcareous cement-filled limestone formed at bathyal depths by bacterial oxidation of methane at a cold seep. This is the third known report of sponges from ancient chemosynthetic deposits.

We describe three scleractinian corals and one species of hydrozoan from the New Pass Range, central Nevada, which together constitute the oldest Triassic cnidarian assemblage from North America. They occur in carbonate rocks tentatively correlated with the Augusta Mountain Formation, Star Peak Group. At generic and higher levels, these cnidarians seem representative of early Mesozoic Tethyan faunas and carbonate lithofacies, but they indicate some endemism. Although the original aragonitic skeletons and microstructure are destroyed by recrystallization, the corals still yield important details allowing their correct taxonomic assignment. They contain the minitrabecular cerioid coral, Ceriostella variabilis new genus and species, the thick-trabecular, thamnasteroid coral Mesomorpha newpassensis new species, and an undeterminable cuifastreid coral tentatively assigned to Cuifastraea. The discovery of Mesomorpha marks the first occurrence of this genus outside the Jurassic and Cretaceous seas. Also discovered is a remarkably corallike hydrozoan, Cassianastraea reussi (Laube), already known from the Carnian stage of the western Tethys. This is the first occurrence of this species outside the western Tethys.