Recently collected specimens of the extinct tayassuine peccary “Cynorca” occidentale (and another indeterminant tayassuid) are described from new excavations along the southern reaches of the Panama Canal. Fossil peccaries were previously unknown from Panama, and these new tayassuid specimens therefore add to the extinct mammalian biodiversity in this region. “Cynorca” occidentale occurs in situ in the Centenario Fauna (new name) from both the upper part of the Culebra Formation and overlying Cucaracha Formation, thus encompassing a stratigraphic interval that includes both of these formations and the previously described and more restricted Gaillard Cut Local Fauna. “Cynorca” occidentale is a primitive member of the clade that gives rise to modern tayassuines in the New World. Diagnostic characters for “C.” occidentale include a retained primitive M1, reduced M3, and shallow mandible, and this species is small relative to most other extinct and modern tayassuine peccaries. Based on the closest biostratigraphic comparisions (Maryland, Florida, Texas, and California), the presence of “C.” occidentale indicates an interval of uncertain duration within the early Hemingfordian (He1) to early Barstovian (Ba 1) land mammal ages (early to middle Miocene) for the Centenario Fauna, between about 19 and 14.8 million years ago. Based on what is known of the modern ecology of tayassuines and previous paleoecological interpretations for Panama, “C.” occidentale likely occupied a variety of environments, ranging from forested to open country habitat mosaics and fed on the diverse array of available plants.

Nine species of fossil isopods have been studied from Cretaceous to Pleistocene rocks of North America. This represents all known species from the Mesozoic and Cenozoic fossil record on this continent. Four species of Palaega were studied. Palaega goedertorum Wieder and Feldmann, 1989, from upper Eocene to lower Miocene rocks of Washington state, has served recently as the basis for restructuring the genus. Emendations are made to species descriptions of Palaega guadalupensis and P. williamsonensis from the Cretaceous rocks of Texas. The fourth species of Palaega, P. lamnae, also from the Cretaceous rocks of Texas, although of doubtful affinities with this genus, was not removed due to lack of sufficient information to reassign it. Two new species are described, Cirolana enigma, from Lower Cretaceous rocks of South Dakota, and Archaeoniscus texanus, from the Cretaceous of Texas. This is the first report of Cirolana from the fossil record. Two sphaeromatid isopods were included: one, Sphaeroma burkartii from Tertiary rocks of Mexico, was not located for study; the other, Eocopea oculata, is from Miocene rocks of southern California. Two specimens of the valviferan genus Saduria, from Pleistocene deposits in Canada, were also studied.

A partial nodosaurid ankylosaur skeleton, consisting primarily of the ilia, hindlimbs, posterior dorsal armor, plus partial forelimb elements and additional armor, was recovered from the marine Point Loma Formation, late Campanian age, north of San Diego, California. The specimen is similar to contemporaneous species of Panoplosaurus and Edmontonia from terrestrial sediments of the western interior, but there are also similarities to the armor of Stegopelta landerensis from marine sediments of earliest Cenomanian age from Wyoming. Skeletal elements critical for generic determination are not preserved, and the specimen is identified as Nodosauridae, incertae sedis. An associated marine invertebrate fauna and nannoplankton flora have revealed some discrepencies in the correlation systems used for Upper Cretaceous marine rocks of coastal California. Hollow limb bones of the specimen are interpreted as a preservational artifact. Nodosaurids had broad ecological tolerances, and visited riparian and coastal environments more frequently than other dinosaurs. However, a review of morphologic and distributional evidence fails to support a theory of amphibious or aquatic habits for nodosaurids.

The distributions of trilobite species were controlled by a combination of habitat preferences and paleogeographic constraints, which tend to limit their extent. The Lower Ordovician trilobite Carolinites genacinaca Ross, 1951, however, had a remarkable range unequaled among polymerid trilobites; it has been recognized on all Ordovician paleocontinents. Its distribution has been explained by an epipelagic mode of life, based on evidence from functional morphology, analogy with modern pelagic crustaceans, and geological occurrence. In such a case, morphological identity throughout its range might be anticipated, if all occurrences can be postulated to be members of a single pandemic population. Rotational superimposition has been used to compare variation within samples drawn from Alberta, Spitsbergen, and Australia with a benchmark population from the western United States. All are morphometrically similar. By any criterion, specimens identical to the benchmark population are found within the Alberta, Spitsbergen and Australia samples, which represent the extremes of the species' geographic range. A lone cranidium from France, previously referred to Carolinites vizcainoi, may be a juvenile of C. genacinaca or C. tasmaniensis; its differences are consistent with ontogeny. A small number of specimens from Siberia and central China show differences in cranidial proportions from the Utah specimens that may be the result of preservational factors and/or photographic technique, or may represent genuine morphological disparity; this could be clarified if more specimens were to become available. This study suggests that C. genacinaca was ubiquitous in the epipelagic environment in a belt that encircled the planet between paleolatitudes of approximately 30°N and 30°S.

A large collection of macrurous decapod crustaceans is recorded from the middle–late Anisian (Middle Triassic) Guanling Formation in Yunnan Province, China. A remarkable assemblage of over 20,000 vertebrate, invertebrate, and plant fossils collectively referred to as the Luoping Biota has been collected from quarries in the vicinity of the city of Luoping. Among these, arthropods including the decapods are the most common element although articulated fish and reptiles are also common. The decapods represent new taxa, including Koryncheiros luopingensis n. gen. n. sp. within Clytiopsidae, a newly elevated family within Erymoidea; Tridactylastacus sinensis n. gen. n. sp. within Glypheidae; and Yunnanopalinura schrami n. gen. n. sp. within Palinuridae. A single specimen has been referred to Palinuridae sp. Koryncheiros luopingensis exhibits a unique cheliped architecture and the second through fourth chelipeds are subchelate, an extremely rare configuration. Tridactylastacus sinensis also exhibits subchelate closures of pereiopods 2–4, but it bears a distinctive subchelate first pereiopod with an intercalated spine between the fingers on the distal margin of the propodus. Yunnanopalinura schrami represents the oldest occurrence of Palinuridae and Achelata. Collectively, these expand our knowledge of Chinese decapods significantly in that only six species of fossil decapods have been described previously from the country.

Alligators and caimans share a close relationship, supported by both molecular and morphological characters. The divergence between alligators and caimans has been difficult to discern in the fossil record. Two basal taxa have recently been described from the Miocene of Panama and Venezuela but have not yet been presented in a joint phylogeny. Continued preparation of the type material of the Venezuelan Globidentosuchus brachyrostris Scheyer et al., 2013 has revealed new characters for scoring in a cladistic framework. In addition, the first lower jaw of the Panamanian Centenariosuchus gilmorei Hastings et al., 2013 is described herein, and additional characters were scored. In total, we conducted five cladistic analyses to better understand the character evolution involved in the establishment of Caimaninae. In each case, Globidentosuchus appears as the basal-most of the caimanine lineage, followed by Culebrasuchus mesoamericanus Hastings et al., 2013 from Panama. Stepwise character additions of synapomorphies define progressively more derived caimanines, but stratigraphic context creates ghost lineages extending from the Miocene to Paleocene. The persistence of two basal taxa into the Miocene of northern South America and Central America supports the concept of a relict basal population in this region. This further supports biogeographic hypotheses of dispersals in both directions between North and South America prior to full land connection.

Four hybocrinid and disparid crinoids from the Middle Ordovician Dunleith Formation (Galena Group) of northern Iowa and southern Minnesota are described: Hybocrinus conicus Billings, Ohiocrinus levorsoni n. sp., Caleidocrinus (Huxleyocrinus) gerki n. sp., and Ectenocrinus simplex (Hall). The first three taxa are rare. Ectenocrinus simplex is an abundant and protean form ranging from the Shermanian to the Maysville and from the Appalachians to the Midcontinent. One Middle Ordovician specimen from the Dunleith is a complete small adult with stem and a lichenocrinid holdfast. The column was largely upright with the crown located about 25 cm above the seafloor. The Middle Ordovician crinoids differ somewhat from the later Cincinnatian material where only young E. simplex exhibit lichenocrinid holdfasts. Older crinoids became detached and were eleutherozoic well before the column was 25 cm long. Thus, the Cincinnatian individuals lost the attachment device earlier during ontogeny than their ancestors in the Middle Ordovician. Unlike most associated crinoids, E. simplex formed a roughly conical filtration net. The arms of E. simplex are extensively branched. Ten main arms bear unbranched ramules on alternate brachials, and the arm structure converges on the pinnulate pattern. Narrow food grooves and short covering plates are present. Analogies with living crinoids indicate that small food particles were caught by small and close-spaced tube-feet. The formation of new plates and ramules at the arm tips increases the size of the food-gathering system throughout ontogeny. The food-gathering capacity comprises the number of food-catching tube-feet times the width of the food grooves, and it measures the number and size of food particles that can be caught. Both size and capacity of the food-gathering system are positively allometric compared to crown volume and the amount of tissue that must be nourished. This is mainly caused by the addition of new ramules at the arm tips, which generates an exponentially increasing plate supply rate. Examination of numerous specimens from various geographic and stratigraphic horizons with multivariate statistics shows that the species was homogeneous throughout its range aside from the differences in living habits mentioned above.

Dissorophoid temnospondyls are widely considered to have given rise to some or all modern amphibians (Lissamphibia), but their ingroup relationships still bear major unresolved questions. An inclusive phylogenetic analysis of dissorophoids gives new insights into the large-scale topology of relationships. Based on a TNT 1.5 analysis (33 taxa, 108 characters), the enigmatic taxon Perryella is found to nest just outside Dissorophoidea (phylogenetic defintion), but shares a range of synapomorphies with this clade. The dissorophoids proper are found to encompass a first dichotomy between the largely paedomorphic Micromelerpetidae and all other taxa (Xerodromes). Within the latter, there is a basal dichotomy between the large, heavily ossified Olsoniformes (Dissorophidae + Trematopidae) and the small salamander-like Amphibamiformes (new taxon), which include four clades: (1) Micropholidae (Tersomius, Pasawioops, Micropholis); (2) Amphibamidae sensu stricto (Doleserpeton, Amphibamus); (3) Branchiosauridae (Branchiosaurus, Apateon, Leptorophus, Schoenfelderpeton); and (4) Lissamphibia. The genera Platyrhinops and Eoscopus are here found to nest at the base of Amphibamiformes. Represented by their basal-most stem-taxa (Triadobatrachus, Karaurus, Eocaecilia), lissamphibians nest with Gerobatrachus rather than Amphibamidae, as repeatedly found by former analyses.

UUID: http://zoobank.org/dadf36db-e003-4af7-bfa7-44d79bc04450

Damage displayed by 18 of 954 relatively mature (> 35 mm diameter) specimens of Gonioloboceras goniolobum (Meek) from North American Midcontinent Upper Carboniferous sediments is interpreted to be bite marks caused by condrichthyans and other fish, particularly the symmoriid shark Symmorium reniforme. It is likely that these and other predators regularly preyed on Gonioloboceras goniolobum because all of the analyzed specimens of Gonioloboceras exhibit some evidence of unrepaired damage, including broached camerae and missing body chambers. Two new characteristics utilized with caution to detect predatory events on ammonoids are raised oval or circular pedestals on internal molds and the breakage and termination of septa in conjunction with a broken external shell. When sufficient damage to the Gonioloboceras conchs occurred during predatory attacks, the broached camerae flooded, the conch became negatively buoyant, and it sank in the vicinity of the attack. When preserved, these conchs form a variable component of an autochthonous fossil accumulation that can include numerous other cephalopod taxa, which also were probably subjected to predatory attacks. Other, but not all, ammonoid accumulations in the fossil record form similar autochthonous deposits, or even autochthonous portions of mixed deposits.

The Lower Pennsylvanian (Morrowan/Atokan) portion of the Fountain Formation in the Manitou Springs, Colorado, area commonly has been interpreted as a subaerial alluvial fan. However, approximately 12 marine-nonmarine cycles, each represented by a discrete progradational sequence, have been recognized within the lower third of the Fountain Formation in this area. The typical cycle is composed of six lithofacies: 1) transgressive-lag conglomerate; 2) offshore mudstone; 3) hummocky crossbedded sandstone; 4) planar crossbedded granular sandstone; 5) low-angle, crossbedded, coarse-grained sandstone; 6) lenticular conglomeratic sandstone. Only lithofacies 6 is nonmarine (alluvial) in origin. Two diverse trace-fossil assemblages (totalling 18 ichnogenera and 20 ichnospecies) within the Fountain Formation are restricted to the marine portions of the section, or to those portions within 1 m below marine-deposited strata. The assemblage includes Arenicolites carbonarius, ?A. ichnosp., Aulichnites parkerensis, two types of Chondrites, ?Conostichus broadheadi, ?Crossopodia ichnosp., Curvolithus manitouensis (ichnosp. nov.), Eione ichnosp., Lockeia ichnosp., Macaronichnus segregatis, Palaeophycus heberti, Palaeophycus striatus, Planolites beverleyensis, Psammichnites plummeri, Rhizocorallium irregulare, ?Skolithos ichnosp., Taenidium serpentinum, ?Teichichnus ichnosp., ?Thalassinoides ichnosp., ?Zoophycos ichnosp., and several unnamed traces.

Trace fossils in the Fountain Formation can be used as indicators of sedimentary processes (e.g., rates of deposition, energy regime). Trace-fossil composition changes along a roughly south-to-north, nearshore-to-offshore gradient, generally reflecting increased influence and duration of normal-marine sedimentation. Ichnotaxa present and their distributions within marine strata in the lower part of the Fountain Formation suggest that they belong to the Curvolithus ichnoassemblage, which has been shown to indicate high sedimentaiton rates in relatively nearshore shelf settings. The Curvolithus ichnoassemblage can be subdivided into Macaronichnus-dominated and Curvolithus-dominated parts. Macaronichnus-dominated portions of the Fountain Formation indicate generally higher wave-energy sedimentation as compared with Curvolithus-dominated portions.

Dimeropyge öpik, 1937, is a genus currently composed of at least 14 similar Middle (predominantly) to possibly lowest Upper Ordovician species from Laurentia (13 species) and Baltica (one species). Possible Lower Ordovician specimens have been illustrated by Ross (1951). Dimeropyge clintonensis Shaw, 1968, is redescribed, based upon additional material of mature topotypes. A new species of Dimeropyge, D. speyeri, is proposed for material from the Esbataottine Formation in the Mackenzie Mountains, northwestern Canada, previously described as D. clintonensis. A phylogenetic analysis of 10 of the 14 species of this genus is presented (the other species are less completely known, and are related to the analyzed species in a more traditional manner). Ontogenies from protaspid to holaspid stages are provided for D. clintonensis, D. speyeri, and D. virginiensis Whittington and Evitt, 1954. The larval stages of these species are very similar, supporting the close relationship between species assigned to Dimeropyge.

A new assemblage of thalattosaurs is described from the Lower to Middle Triassic Sulphur Mountain Formation of eastern British Columbia. The following new species are described: Thalattosaurus borealis n. sp.; Paralonectes merriami n. gen. and sp.; and Agkistrognathus campbelli n. gen. and sp. In addition, specifically indeterminate material is described. This assemblage extends the geographic range of the Thalattosauria to Canada and demonstrates that thalattosaurs were more taxonomically diverse and widely distributed than previously thought.

Twenty-three species of Campanian, Maastrichtian, Paleocene, and Eocene freshwater gastropods from northeastern Mexico are described, including eight new species: Viviparus mcbridei, Pachychilus (Pachychiloides) lawtoni, Melanoides (Melanoides) yolandae, Melanoides (Melanoides) wollebeni, Physa cepedaensis, Mesolanistes magnus, Mesolanistes murrayi, and Gyraulus zoltani. Specimens were collected from fine-grained, green sandstone and mudstone, red mudstone, and as hematized remains in fine light-brown sandstones belonging to the following stratigraphic units of northeastern Mexico: Cerro del Pueblo (Campanian, Parras Basin), Olmos (Maastrichtian, Sabinas Basin), Las Encinas (Paleocene, Parras Basin), and Carroza (Eocene, La Popa Basin) Formations. All except two of the genera (?Pyrgulifera and Mesolanistes) have recent representatives. Review of habitats of living species of the six extant genera and interpretations of sample lithologies support the inference of dominantly freshwater paleoenvironments. Only one Maastrichtian locality is interpreted confidently to have had a brackish water influence.

Genus Crocodylus is considered to have originated in Africa during the Early Miocene but it is only in the Late Miocene that there are evidences of dispersal toward Europe, where tomistomines and the alligatoroid Diplocynodon were widespread since the Paleogene. Revision of the type material of Crocodylus bambolii Ristori, 1890, a Tortonian crocodylian from the renowned Oreopithecus localities in central Italy, excludes it from Diplocynodon. The morphology of the remains, combined with chronology and biogeography, confirms its identity as cf. Crocodylus. The validity of the species Crocodylus bambolii is however not supported by the available morphological characters so that a solid differential diagnosis cannot be realized. It is therefore here proposed to consider Crocodylus bambolii as a nomen dubium. The European Late Miocene distribution of short-snouted crocodylians sees only alligatoroids in western Europe and, curiously, only crocodylids in the Central Mediterranean area. The Tusco-Sardinian and the Apulo-Abruzzi paleobioprovinces, whose lands are nowadays part of the Italian peninsula, are apparently the only European areas inhabited by short-snouted crocodylids, which are at the same time among the last crocodylians of the continent. The isolated teeth from Fiume Santo and Scontrone, two localities of these palebioprovinces, are also not Diplocynodon-like, but further material is needed to identify their owners with confidence.

Limestones of Silurian age (late Llandovery–Ludlow) from the Heceta Formation of southeastern Alaska (Alexander terrane) yield a diverse assemblage of calcified microbial organisms. Fourteen taxa are described, including the cyanobacteria Girvanella and ?Hedstroemia, possible cyanobacteria Epiphyton, Ludlovia, and Renalcis, three species of “Solenopora,” and microproblematica Rothpletzella and Wetheredella. Diagnoses and descriptions are also given of the new epiphytacean genus Hecetaphyton n. gen. and new microproblematica genera Tuxekanella n. gen. and Sphaerina n. gen.

Mineral separates of five tuffs interbedded in the mammal-bearing Huayquerías and Tunuyán formations in Mendoza Province, west-central Argentina, were dated by the 40K-40Ar method. At the locality of Rio Seco Ultima Aguada on the east side the Meseta Guadal three biotite concentrates of a tuff from a level that apparently corresponds to the very top of the Huayquerias Formation (or less probably to the very bottom of the Tunuyan Formation, sensu Dessanti, 1946) yielded an average age of 5.8 ± 0.1 Ma. The boundary between the Huayquerias Formation (namesake and type formation and fauna of the Huayquerian Land Mammal Age) and the Tunuyan Formation (which contains a Montehermosan age fauna at this locality) is thus about 5.8 Ma. At the locality of Rio Seco de la Salada on the west side of the Meseta Guadal, glass concentrates from two tuffs in the upper part of the Tunuyan Formation yielded ages of 2.6 ± 0.1 and 2.4 ± 0.3 Ma, respectively (the latter date is from a tuff located 90 m stratigraphically above the former). These dates indicate that the rocks and faunas from the upper part of the Tunuyan Formation are of Chapadmalalan (i.e., 2.8 to 2.5 Ma) and Uquian (i.e., 2.5 to 1.5 Ma) age. The faunas from the lower and middle parts of the Tunuyan Formation on the east side of the Meseta Guadal are apparently all of Montehermosan age (i.e., ca. 6.0 to 2.8 Ma).

Middle and Late Permian sphinctozoan sponges described here are from the Middle Permian Maokou and the Upper Permian Wujiaping and Changxing Formations. Most are from near Xiangbo, northwestern Guangxi, but a few are from Upper Permain patch reefs from Laolongdong in eastern Sichuan. The new genera, the porate Imbricatocoelia and the aporate Glomocystospongia, are described, the latter as the type genus for the new family Glomocystospongiidae. New species described include Amblysiphonella specialis, Amblysiphonella spinosa, Amblysiphonella sp. A, Amblysiphonella sp. B, Colospongia maxima, Colospongia sp. A, Imbricatocoelia elongata, I. irregulara, I. obconica, I. paucipora, Neoguadalupia explanata, Subascosymplegma? paracatenulata, Rhabdactinia depressa, R. irregulara, R. squamula, Salzburgia nana, Glomocystospongia gracilis, Sollasia absita, and S. spheroida. New occurrences of Amblysiphonella merlai? Parona, 1933, Lichuanospongia typica Zhang, 1983, Polycystocoelia huajiapingensis Zhang, 1983, Intrasporeocoelia hubeiensis Fan and Zhang, 1985, Rhabdactinia columnaria Yabe and Sugiyama, 1934, Uvanella irregulara Ott, 1967, Stromatocoelia asiatica Zhang and Fan (in Fan and Zhang, 1985), and Tebagathalamia cylindricum Senowbari-Daryan and Rigby, 1988, are reported. The described assemblage represents the most diverse Permian sphinctozoan sponge fauna known from Asia.

Sixteen genera and 27 species of Recent brachiopods are reported from the far southern Pacific Ocean and adjacent parts of the South Atlantic and southern Indian Ocean. These specimens extend the known geographic ranges of at least 10 species and the known bathymetric ranges of at least seven species. The new material gives greater support to the idea that many Recent brachiopod species have a wide geographic range and calls into question the very limited geographic ranges of many species known only from the fossil record. Puncta density appears to be a useful character for distinguishing Neothyris compressa and N. lenticularis. At least nine different types of geographic distribution are represented among the species studied for this paper. Areas of moderate depth on seamounts, particularly along oceanic ridges and on oceanic rises, may form important geographic areas of distribution, avenues of dispersal, and barriers to brachiopods. Four examples of polytypic species are cited. The new specimens lend additional support to the notion that one polytypic species of Liothyrella extends, with clinal morphological changes, from southernmost South America to Antarctica. Students of modern brachiopods are urged to consider large-scale geographic variation within species and not to hide it with finely delimited taxa. This approach has the potential to lead, in both modern and ancient brachiopods, to a taxonomy with fewer and more meaningful species and genera. Progenetic changes seem to be a common adaptive strategy in brachiopods on largely soft substrates and in deep water. The progenesis may be short term within a single species or long term involving evolution of new species and genera.

A partial skeleton tentatively referred to the Lower Cretaceous pliosauroid genus Leptocleidus is described from predominantly Aptian (Lower Cretaceous) opal-bearing deposits of the Bulldog Shale near Andamooka in South Australia. Small size coupled with incomplete fusion of the basicranial elements, vertebral centra, neural arches and cervical ribs, and incomplete ossification of the articular surfaces on the propodials and distal limb bones, indicate that the specimen was at an early stage in its ontogeny. Comparison with more mature specimens attributed to Leptocleidus spp. highlights several growth-related differences, particularly a marked disparity in proportions of the humerus and femur relative to the estimated maximum body length. Changes in the cranial skeleton during growth are harder to document because of the fragmentary nature of the skull. Nevertheless, fusion of some cranial sutures and well-developed cranial joint surfaces suggest that extensive ossification may have taken place in parts of the skull during early ontogeny. the potential implications of these findings for feeding, locomotion, and behavior in juvenile plesiosaurs are discussed.

The ‘granular’ wall microstructure of the Ordovician stenolaemate bryozoan Dianulites Eichwald, 1829, has been studied using ultrathin sections, scanning electron microscopy (SEM), analytical SEM, and cathodoluminescence. The timing of recrystallization and the presence of microdolomite inclusions in the skeletal walls implies that the original skeleton consisted of high-magnesium calcite (HMC). Although found in some modern cheilostomes, HMC has not been recorded in living stenolaemate bryozoans, but appears to have also been present in Nicholsonella and a few other Ordovician genera traditionally assigned to the trepostomes or cystoporates. The Russian type species of Dianulites, D. fastigiatus Eichwald, 1829, is revised and recorded for the first time in North America from the Fillmore Formation (Lower Ordovician) of Utah. Unusually among bryozoans, D. fastigiatus has turbinate, cone- or horn-shaped colonies, straight to slightly curved, with zooids opening on the flat, broad end of the cone; the sides of the cone comprise calcified exterior walls. This growth-form resembles some solitary rugose corals and other benthic animals thought to have lived with all but their tops buried in soft sediment. Such an interpretation is supported in Dianulites by the scarcity of epibionts on the exterior walls of the cone and by the occurrence of specimens comprising stacks of subcolonies, suggesting periods of partial burial of the living tissues by sediment.