Exceptionally rich and well-preserved silicified exuviae comprising numerous immature growth stages allow the tracing of detailed morphological and morphogenetical features of the reduced-eyed phacopid species Cryphops? ensae (Richter and Richter, 1926) from the latest Famennian of Thuringia (Central Germany). Ontogenetic features of this species are more similar to those of Phacops than to Trimerocephalus.

Echinoderms of the Middle Ordovician Platteville and lower Galena Groups of north-central Illinois and south-central Wisconsin are represented by at least seven classes including the Homoiostelea, Cystoidea, Crinoidea, Stelleroidea, Edrioasteroidea, Cyclocystoidea, Echinoidea, and possibly Holothuroidea. The most abundant and diverse echinoderms are monocyclic and dicyclic inadunate and camerate crinoids, of which the cupulocrinids and glyptocrinids are best represented. Thirteen new species and one new genus of crinoids are described: Cremacrinus guttenbergensis, Anulocrinus forrestonensis, Isotomocrinus minutus, Carabocrinus oogyi, Dendrocrinus? springeri, Merocrinus britonensis, Cupulocrinus plattevillensis, C. molanderi, Reteocrinus rocktonensis, R. spinosus, Traskocrinus mahlburgi (n. gen. et sp.), Rhaphanocrinus buckleyi, Glyptocrinus charltoni, and G. pustulosis. One new species of rhombiferan cystoid, Coronocystis durandensis, is also described. Echinoids of the family Bothriocidaridae (Bothriocidaris solemi n. sp. and Neobothriocidaris templetoni n. sp.) are reported for the first time from North America and appear to be the earliest recorded occurrence. Remains of a third bothriocidarid characterized by coalesced podial pores have also been discovered. Light and scanning electron microscopy of well preserved cyclocystoid specimens reveal a number of previously undescribed morphologic features of the central disc and submarginal ring that may shed some light on their functional morphology.

Cupulocrinus gracilis Ramsbottom from the Upper Drummuck Group Starfish Bed at Thraive Glen near Girvan, Scotland, is here reassigned to C. drummuckensis n. sp.

Echinoderms are associated with an abundant and diverse fauna consisting largely of suspension feeders, primarily strophomenid and orthid brachiopods and trepostome and cryptostome bryozoans. Other common groups include corals, trilobites, sponges, and mollusks. Filamentous brown, foliose red and siphonaceous green algae are associated with the fauna at some localities.

Carbonate rocks of both the limestone and dolostone facies of the Platteville (Briton, Walgreen and Forreston Members) and lower Galene Groups in the study area consist primarily of abundant shelly invertebrates occurring as whole and broken, unabraded, commonly articulated remains “floating” in a calcisiltite matrix that is highly bioturbated. Carbonate sediments appear to have been deposited in a near-to below wave base, highly stable, open marine environment characterized by low depositional slopes, good circulation and low terrigenous influx.

A trace-fossil assemblage is exposed in the uppermost portion of an interpreted tidal sand-flat deposit in the Upper Mississippian Tar Springs Sandstone in southwestern Illinois. Sedimentary structures, indicative of a tidal origin for this unit, include herringbone crossbeds, flaser and lenticular beds, reactivation surfaces, small channel scours, and shrinkage cracks. The trace fossils include trackways, trails, feeding structures, dwelling burrows, and escape structures. Vertical dwelling and escape structures dominate the assemblage with lesser numbers of horizontal and inclined traces. The ichnological and sedimentological characteristics are diagnostic of the Skolithos ichnofacies. Preservation of the assemblage at the top of the Tar Springs Sandstone was the result of substrate stabilization as the tidal flat subsided and was transgressed. The present trace-fossil assemblage probably was formed by a combination of a pre-omission tidal-flat suite and an omission suite formed during and after the transgression. Preservation of the assemblage suggests a passive transgression with minimal scouring and reworking of the tidal-flat deposit.

We describe Numbigilga ernielundeliusi new genus and species, a highly unusual marsupial represented by a partial right mandible with p2-m4 and a left upper molar from early Pliocene deposits at Bluff Downs, Queensland, northeastern Australia. Numbigilga n. gen. is characterized by a bunodont dentition with a number of striking specializations, and we refer it to Numbigilgidae new family. This taxon shares a range of dental apomorphies with various bunodont marsupial groups from the Late Cretaceous of North America and Paleogene of Gondwana. However, many of these features are most likely highly homoplastic within marsupials, reflecting convergent adaptations to a frugivorous-omnivorous diet. Other dental characters suggest possible affinities to the Australian order Peramelemorphia (bandicoots). Alternatively, Numbigilga may be a representative of an entirely new order of Australian marsupials. in the absence of more nearly complete specimens that might clarify its relationships, we refer Numbigilga to Marsupialia incertae sedis. We consider the distributions of a number of dental characters in bunodont marsupials and argue that no North American Late Cretaceous taxa can be convincingly referred to the order Polydolopimorphia. Thus, polydolopimorphians continue to be known only from the Cenozoic of Gondwana, with no fossil evidence that their initial divergences occurred in North America.

The Sinoalidae, as one of the three Mesozoic froghopper families, was recently recognized from the latest Middle–earliest Late Jurassic Daohugou Biota of northeastern China. We herein report some new materials from the same horizon and locality, providing some new insights on morphological diversity and evolution of this family. Shufania hani new genus new species indicates that the relative branching position of veins M and CuA of the forewing is highly variable within the Sinoalidae and not appropriate for family-level diagnosis. The venations of three reported sinoalid hind wings are conservative, likely due to its simplified topology and reduced terminal branches. Color patterns of hind wings are likely variable for different sinoalid froghoppers. However, considering that color pattern is easily weakened or even erased by diagenetic processes for imprint fossils, the morphological character is not reliable for distinguishing different sinoalid taxa. Additionally, our new material suggests that the number of lateral spines of the hind tibia can vary intra-individually for sinoalids, just as in some recent froghoppers.

The Prout Dolomite of north-central Ohio lies disconformably above the lowest Givetian (upper Middle Devonian) Plum Brook Shale and below the lowest Famennian (upper Upper Devonian) Ohio Shale. A sample from its base yielded over 4,000 diverse conodont specimens. Included is Polygnathus ansatus Ziegler and Klapper, 1976, the index species for the Middle varcus Subzone, which is not reported from strata of this age in Ontario and Indiana, a fact that long caused their miscorrelation with the Lower varcus Subzone. Also present is P. rhenanus Klapper, Philip, and Jackson, 1970, considered to be also indicative of the Middle varcus Subzone in North America, and P. ovatinodosus Ziegler and Klapper, 1976. Lowest occurrences of the latter are in the middle part of this subzone; its presence indicates correlation with the lower Tully Limestone of New York, the basal unit of the Taghanic Series. The Prout and equivalent strata in the region therefore represent a long unrecognized continuous time-rock unit created by Johnson's (1970) Taghanic onlap. The collection includes a new species of Ancyrolepis, A. huntleyi; a new species of Polygnathus is left in open nomenclature, as are nine specimens assigned to Tortodus but of otherwise uncertain taxonomic status.

Givetian conodont correlation between North America and the Global Stratotype Section and Point established by the Subcommission on Devonian Stratigraphy (SDS) in Morocco is extremely problematical because of relatively erratic distribution (probably owing to limited ecologic adaptability) of P. ansatus and P. hemiansatus Bultynck, considered herein to be an early morphotype of P. ansatus. The base of the Givetian Stage has been defined by the SDS as coinciding with the lowest occurrence of P. hemiansatus. The only possible evidence for the SDS's hemiansatus Zone in North America involves reported occurrence of that morphotype in the uppermost Arkona Shale of Ontario, a position above the top of the Plum Brook Shale, which has been considered to be of Givetian age for decades. Also it appears that the interval between the Eifelian (lower Middle Devonian) kockelianus Zone and the hemiansatus Zone at the SDS's global-stratotype section in Morocco is of questionable age and probably too thin to represent continuous sedimentation. Adoption of a widely recognized faunal break at the base of strata deposited during the If T-R cycle of North America and Europe as the base of the Givetian could provide a sound alternative.

Description of two new species of macruran decapod crustaceans, Hoploparia uzbekensis and Linuparus dzheirantuiensis, from Late Cretaceous rocks in the Kyzylkum Desert, Uzbekistan, represents the first published record of decapods from that country. Hoploparia is considered to be an intact, integrated genus. Specimens of Hoploparia uzbekensis and Linuparus dzheirantuiensis collected from the Aitym and Bissekty formations, respectively, are preserved as altered cuticular material in a sandy matrix. Specimens of Hoploparia and Linuparus collected from the Uchkuduk and Dzheirantui formations, respectively, are preserved as ironstone replacements, an unusual preservation style for decapods. the cephalothorax on the specimen of Linuparus from the Dzheirantui Formation has been partially broken in a manner suggestive of predation. the lateral thoracic flanks of the holotype of Linuparus dzheirantuiensis bear a raised, ridged area suggestive of a stridulating structure. These genera, although cosmopolitan in the Cretaceous fossil record, have not been recognized previously in central Asia.

Taxonomic analysis is provided for a Middle Pennsylvanian macrofloral assemblage collected from clastic wetland deposits in Clay County, Indiana, on the eastern margin of the Illinois Basin. Adpressed plant fossils were recovered from four distinct beds in the lowermost Staunton Formation, positioned above the Minshall Coal (uppermost Brazil Formation), part of a succession deposited near the Atokan-Desmoinesian boundary. The assemblage of 22 fossil-taxa is dominated by pteridosperms (including Neuropteris flexuosa, Macroneuropteris scheuchzeri, Alethopteris densinervosa, Neuropteris ovata, Eusphenopteris neuropteroides, and Neuropteris missouriensis) with lesser cordaitaleans (Cordaites spp. indet.) and sphenopsids (particularly Sphenophyllum cuneifolium). Lycopsids are uncommon, and ferns are rare. In contrast, the microfloral assemblage from the Minshall Coal and overlying clastic units is dominated by lycopsid and tree fern spores. Comparisons with established biozonation schemes yield different ages depending on the regional biostratigraphic framework used: (1) latest Bolsovian (Radiizonates difformis Biozone, American microfloras); (2) latest Bolsovian or earliest Asturian (‘Neuropteris’ rarinervis Biozone, Appalachian Basin macrofloras); or (3) earliest Asturian (Linopteris obliqua Biozone, European macrofloras). The placement and correlation of the Bolsovian-Asturian and Atokan-Desmoinesian boundaries, which have traditionally been equated by palynology, are evaluated in the context of this discordance. Several revised stratigraphic scenarios are proposed for this interval in the Illinois Basin, which is being increasingly recognized as a time of significant environmental change throughout Euramerica. Homotaxial comparisons with European macrofloral assemblages indicate that, of the 18 biological taxa recorded, between 14 and 17 (78–94%) also are common in coeval wetland deposits in Europe. The similarities exemplify the spatial conservatism and low diversity of wetland plant communities over vast areas of tropical Euramerica, a manifestation of the intrinsically stressful conditions that characterize such habitats, and indicates that neither the Laurentian Shield nor the Appalachian-Variscan Mountains were an insurmountable barrier to plant dispersal during the Middle Pennsylvanian.

We undertake a redescription of the equid sample from the Early Pleistocene of Roca-Neyra, France. This locality has been recently calibrated at the Pliocene/Pleistocene boundary (2.6 ± 0.2 Ma) and therefore it is of interest for the first appearance of the genus Equus and last appearance of hipparionine horses. The Roca-Neyra equid sample, re-analyzed herein using morphological, morphometrical, and statistical analyses, has revealed the co-occurrence of Plesiohipparion cf. ?P. rocinantis and Equus cf. E. livenzovensis. The analysis undertaken on several European, African, and Asian “Hipparion” sensu lato species from late Miocene to Early Pleistocene has revealed different remnant Hipparion lineages in the Plio-Pleistocene of Europe: Plesiohipparion, Proboscidippaion, and likely Cremohipparion. The discovery of the first European monodactyl horse, Equus cf. E. livenzovensis correlates Roca-Neyra with other 2.6 Ma European localities in Italy, Spain, and in the Khapry area (Azov Sea region). The morphological description of the Equus cf. E. livenzovensis lower cheek teeth has highlighted intermediate features between the North American Pliocene species Equus simplicidens and Early Pleistocene European Equus stenonis. Our study supports the hypothesis that E. livenzovensis is a plausible evolutionary predecessor for the Equus stenonis group. These observations underscore the importance of Roca-Neyra as an important locality for the last European hipparions and the first Equus in the Early Pleistocene of Europe.

Small holes of irregular outline and mainly 0.2 to 1.5 mm in diameter are present in the exteriors of molluscan shells obtained from the latest Quaternary transgressive sequence on the Orange Shelf, Benguela region, off southwestern Africa. In shell interiors, the shell surrounding the holes is broken out to form flaring, conical spalls. The holes are clearly not borings, but are punctures caused by a small, pointed object having been forcefully driven into the shell. The holes in bivalves occur preferentially in small, thin-shelled tellinids and are nonrandomly placed in the central portions of valves. It is proposed that the holes are praedichnia produced by the rapid, ballistic-like raptorial strikes of spearing stomatopods, the pointed dactyl tips having penetrated the shells. Associated evidence of shell smashing, consisting of large holes in valves and gastropod whorls, supports the suggestion of stomatopod activity. The only stomatopod that inhabits the Benguela ecosystem, the spearer Pterygosquilla armata capensis Manning, 1969, is the probable tracemaker. Although shell nearly 1 mm thick has been pierced, the apparent selection of thin-shelled tellinids (0.14 to 0.34 mm thick) may reflect the requirement of shelling smashing in order to access the tissues. Nevertheless, the spearing of shelled prey is atypical for stomatopods and therefore confirmatory zoological observations are required, particularly to clarify the context of shell spearing. The ichnogenus Belichnus is proposed to accommodate these unique traces of pointed impacts, with ichnospecies B. monos (single punctures) and B. dusos (combined punctures) to accommodate the main morphological varieties observed.

We used up to 28 morphological characters to discriminate and describe species of the genus Cupuladria based on entire colony specimens collected from both coasts of the Isthmus of Panama. The characters included a combination of zooidal features traditionally used in cheilostome taxonomy and nontraditional characters such as colony size, shape, and an index of calcification of the colony, as well as the size of the basal sectors and their number of pores. Species were discriminated by a series of repeated multivariate cluster and discriminant analyses until the majority of specimens were assigned to their putative species with high statistical confidence. Nontraditional characters contributed significantly to the power of the analyses. Colonies fell into two highly distinct groups most clearly recognized by the presence or absence of vicarious avicularia, which agrees well with previous molecular genetic analyses. Further analyses of each of these two groups considered separately resulted in the discrimination of eight species. These include two previously described Caribbean species, C. biporosa Canu and Bassler, 1919 and C. surinamensis Cadée, 1975, and six new species: C. multesima, C. incognita, C. cheethami, and C. panamensis from the Caribbean, and C. pacificiensis and C. exfragminis from the eastern Pacific. There was also good correspondence between major clades within these morphologically defined groups and the previous molecular analysis, although 20% of the specimens could not be distinguished from their cognate (“geminate”) species from the opposite ocean. The high ratio of undescribed to described species and higher diversity in the Caribbean than eastern Pacific agree well with newly described patterns from other cheilostome genera based on similar analyses. Quantitative morphometric studies are essential to study biologically meaningful patterns of cheilostome speciation and macroevolution in the fossil record.

The class Somasteroidea Spencer, 1951, is basal within the subphylum Asterozoa. Members are most readily recognized by presence of series of rod-like so-called virgal ossicles extending laterally from each ambulacral ossicle. Five somasteroid genera are recognized and assigned to two families. Four genera are Gondwanan, three of these (Chinianaster, Thoralaster, Villebrunaster) from the Lower Ordovician Tremadocian of France and one (Archegonaster) from the Middle Ordovician upper Darriwilian of the Czech Republic. The fifth genus, Ophioxenikos, is Laurentian from the Floian of Nevada. Catervaparmaster, previously assigned to the Somasteroidea, is left in open nomenclature; absence of virgal-series ossicles favors a lineage apart from the principal asterozoan clades. Asterozoan fossils are readily separated from fossils of other echinoderm groups. The subphylum therefore is thought to be monophyletic, its ancestry unknown. Skeletonized representatives of the four major asterozoan clades first occur through a relatively narrow Early Ordovician stratigraphic interval. Robust skeletons therefore are thought to have evolved after a time of unknown duration including only lineages that were no more than weakly calcified. The French occurrences are from a relatively deep distal shelf setting on soft substrates whereas the Nevada occurrence was in a shallower, active setting. Differences document early ecologic diversification.

Although putative corals of uncertain affinities occur in the early Cambrian, the earliest definite tabulate corals have not been described prior to the Early Ordovician in North America. This paper reports a new finding of a tabulate-like coralomorph forming part of biostratigraphically well-constrained reef mounds in the latest Cambrian–Early Ordovician La Silla Formation in the Argentine Precordillera. The oldest record of the coralomorph genus Amsassia is reported and a new species, A. argentina, is erected. The discovery of this genus in the lowermost Ordovician modifies the previously proposed paleogeographic distribution and patterns of origination and migration routes of this coral-like organism. Amsassia argentina n. sp. constitutes a main framework builder together with a complex microbial consortium. This oldest occurrence of Amsassia as a reef builder represents a new record of a skeletal organism in the gap of metazoan reef constructors after the demise of archaeocyaths in the late early Cambrian.

The Nasep and Huns members of the Urusis Formation (Nama Group), southern Namibia, preserve some of the most diverse trace-fossil assemblages known from the latest Ediacaran worldwide, including potentially the world's oldest “complex” vertical sediment-penetrating burrows. These sediments record relatively diverse communities of bilaterian metazoans existing before the base of the Cambrian and an increase in the intensity of metazoan ecosystem engineering behaviors that could eventually produce profound changes in the character of the Phanerozoic sedimentary record (the “agronomic revolution”). Despite this, relatively little about this trace-fossil assemblage is known. We explore the Nasep–Huns transition at two localities in the Witputs sub-basin and describe the trace- and body-fossil diversity present in these horizons alongside a paleoenvironmental reconstruction. We document eight unique ichnotaxa from these localities, including well-preserved “probes” potentially left by priapulids. We also report the first occurrence of Corumbella from Namibia, helping to establish a biostratigraphic link between Namibia, Brazil, Paraguay, Iran, and the southwestern United States. Last, we find that several ichnotaxa, in particular small treptichnids, appear to be preferentially preserved on the bases of gutter casts, hinting at the potential existence of an unusual late Ediacaran preservational window with possible implications for timing the first appearance of key bilaterian behaviors.

The Pliocene fossil porpoise SDSNH 65276 has extremely elongate mandibular morphology, unlike that of any marine amniote, and is superficially most similar to the living bird species known as skimmers (Rynchops sp.). Endocasts of the pterygoid sinuses and endocranial cavity were digitally segmented from high-resolution X-ray CT scans of the specimen to explore internal anatomy of functionally and phylogenetically important anatomical features of this specimen and odontocetes in general. The sinuses are similar in volume and shape to extant porpoise species, but the dorsal extension of the preorbital lobes are particularly elongate as in the harbor porpoise (Phocoena phocoena). The cranial endocast also shows similarities with extant porpoises, but has much deeper interhemispheric fissures, which are filled by ossified meninges, particularly a deep falx cerebri and shallower tentorium cerebelli. Ossifications of these parts of the meninges may reflect faster angular accelerations of the head, deeper diving ability, or both. Penetrations of the endocranial cavity for cranial nerves and blood vessels are like those of extant porpoises. The internal skull morphology of this unique delphinoid sheds additional light both on its phylogenetic affinities and novel odontocete adaptations.

Pleurocystites strimplei new species, from the Galena Group of Iowa and Minnesota, is closely related to P. squamosus Billings from the Appalachians and Michigan. Numerous specimens provide information about growth, living habits, functional morphology, and respiration. The development of P. strimplei n. sp. is largely isometric with several exceptions. New dichopores form throughout ontogeny. Length of the dichopores and the area available for respiration are characterized by strong positive allometry relative to the volume of the animal. The length of the distal stem increases with respect to the size of the theca. During life the aboral side faced up. Some animals were largely covered by a thin layer of sediment whereas others lay directly on the seafloor. The orientation of the brachioles is most consistent with deposit feeding. Quantitative models of respiration suggest that the pectinirhombs accounted for over half of the needs of youngsters but this contribution falls to about 38 percent in adults. Respiration by the surface area of the theca and the water vascular system provide small amounts of oxygen, especially for animals living on the surface of the seafloor. Cloacal pumping or a similar type of respiratory device probably furnished the remainder of the oxygen required by P. strimplei n. sp. The morphometric data in conjunction with parameters taken from Recent oceans and echinoderms produce a plausible respiration budget, which is affected by size, age, allometry, and living orientation.

Two new species of pectinid bivalves, Camptochlamys alaskensis and Chlamys aquilonia, are present in shallow-marine deposits near Ocean Point, northeastern Alaska, at about 70°N latitude. The precise age of these deposits is debatable, but paleontological and isotopic age estimates indicate placement near the Cretaceous–Tertiary boundary. The occurrence of Camptochlamys extends the chronostratigraphic and geographic range of this genus, previously unknown from any strata above the uppermost Jurassic (Tithonian) of Europe and unknown from any strata in North America. In contrast, the new Chlamys species represents an evolutionary advance beyond its nearest relative in the Maastrichtian of northern Europe and resembles Cenozoic members of its clade in certain features of shell microstructure. These new species are thus a microcosm of the debate regarding the age of these deposits and strengthen the hypothesis that the Ocean Point fauna lived in an Arctic Ocean basin that was isolated from the world ocean.

Thin beds of silty limestone within a Ludlovian (Ludfordian) section of the Cape Phillips Formation on Cornwallis Island, Arctic Canada, contain numerous specimens of noncalcified macroalgae in association with dendroid and graptoloid graptolites, brachiopods, and trilobites. The algal material, preserved as carbonaceous compressions, represents three new taxa, each characterized by a central axis surrounded by laterals. Laterals of Eocladus xiaoi n. gen. n. sp. are thin and branch to the fifth order whereas those of Chaetocladus captitatus n. sp. are undivided and form a distinctive capitulum. Thalli of Palaeocymopolia nunavutensis n. gen. n. sp. have a branched, serial-segmented form and a corticated structure. On the basis of thallus architecture, all three taxa are assigned to the extant green algal order Dasycladales. Parallels exist between this macroalgal assemblage and a modern macroalgal association in Florida Bay.

The obolellates represent a poorly understood group of the oldest known cosmopolitan calcareous rhynchonelliform brachiopods. They made their first appearance in the early Atdabanian and became extinct at the end of the Middle Cambrian. Consequently, any information concerning the soft anatomy of this ephemeral lineage of brachiopods has great phylogenetic significance. This is the first report on two specimens of an obolellate with fine preservation of soft parts including the pedicle, marginal setae and possible imprints of a spiral lophophore, recovered from the early Cambrian Chengjiang Konservat Lagerstätte of Kunming, southern China. The setae are thin and densely fringed along the shell margin. The stout pedicle is distinctly composed of densely stacked tabular bodies, lacking a central coelomic lumen; it emerges through a possible foramen, and slightly tapers posteriorly with the distal end attached to exoskeletons of other organisms.

The hurdiid radiodont Cambroraster is characterized by a prominent horseshoe-shaped head carapace, which bears conspicuous posterolateral spinous processes and covers half of the body length, and a pair of frontal appendages possessing rake-like endites. Here we report the discovery of characteristic central and lateral elements as well as a possible appendage endite for Cambroraster from the Cambrian Wuliuan Mantou Formation of North China. This discovery suggests that Cambroraster had dispersed over a wide biogeographic range and expands the geographic range of Hurdiidae. The increasing discoveries of exceptionally preserved fossils in the Upper Shale Member of the Mantou Formation indicate that this horizon is a promising Burgess Shale–type Lagerstätte.