Borings in fossil turtle shells collected from the lowermost beds of the early Eocene Cathedral Bluffs Tongue of the Wasatch Formation in the northwestern part of the Green River Basin near South Pass, Wyoming, are herein described. Individual turtle shells in the study area are characterized by as few as one or two and as many as >100 borings. The borings include both non-penetrative forms (those which do not pass fully though the shell) as well as penetrative forms (those which pass fully from the exterior to the interior surface of the shell). All non-penetrative forms occur on external surfaces of the carapace and plastron (i.e. those that would have been accessible while the host taxon was alive). Two new ichnogenera and four new ichnospecies are established to describe these borings. Karethraichnus (new ichnogenus) includes three ichnospecies: K. lakkos (new ichnospecies), K. kulindros (new ichnospecies), and K. fiale (new ichnospecies). Karethraichnus lakkos are shallow (non-penetrating), hemispherical pits with rounded, to flattened bases. Karethraichnus kulindros are deep, non-penetrative traces with a cylindrical profile, an axis approximately perpendicular to the substrate surface and with rounded to flattened, hemispherical termini. Karethraichnus fiale are penetrative traces with a cylindrical to bi-convex or flask-shaped profile, and an axis approximately perpendicular to the substrate surface. Thatchtelithichnus (new ichnogenus) Thatchtelithichnus holmani (new ichnospecies) consist of non-penetrative borings into a bone substrate. They consist of a ring-shaped trace, with a central pedestal or platform. The position of the borings on the shells, and evidence of syn-emplacement healing of the borings in several of the turtles, indicates that these borings were emplacement by ectoparasites/mesoparasites while the animals were living. Similar traces in modern emydid turtles are attributed to ticks, leeches, or spirorchid liver flukes.

A newly discovered Verbeekina assemblage from the Xiaoxinzhai Section in the Baoshan Block in western Yunnan, China, provides additional data for better understanding fusulinid biostratigraphy and the thermal condition of middle Permian (Guadalupian) seawater of this block. This assemblage comprises 11 species of six genera, including Verbeekina, Pseudodoliolina, Sumatrina, Yangchienia, Xiaoxinzhaiella, and ?Rugosochusenella. The age of this assemblage is considered to be Midian (approximately Capitanian), based on combined evidence of stratigraphic position and specific composition. Furthermore, this assemblage bears two unusual attributes: overwhelming dominance of Verbeekina and relatively low total diversity, compared with coeval fusulinids from South China, which represents a paleo-tropical setting during the middle Permian. These features indicate that the Baoshan Block was probably located in a subtropical setting with warm water during the Midian time; however, its water temperature was still not as optimal as the tropical area (e.g., South China) for the diversification of fusulinids.

Kinosternon Spix, 1824, was widespread in xeric to savanna associated paleowetlands across North America during the middle–late Miocene and steadily diversified following its first occurrences in the Hemingfordian. In the middle Miocene, Kinosternon rincon n. sp. occurred in the late Barstovian Cerro Conejo Formation of north central New Mexico, perhaps concurrently with Kinosternon pojoaque Bourque 2012a from the Tesuque Formation. Subsequent late Miocene kinosternine fossils indicate that at least three potentially contemporaneous species existed throughout the Clarendonian. These are Kinosternon pannekollops n. sp., from the Ogallala Formation of northern Texas; Kinosternon wakeeniense, n. sp., from the Ogallala Formation of northwestern Kansas and Ash Hollow Formation of south-central Nebraska; and Kinosternon notolophus n. sp., from the Alachua and Statenville formations of northern Florida. Kinosternon rincon is phylogenetically nested between the Kinosternon flavescens (Agassiz, 1857) group (=Platythyra Agassiz, 1857) and more derived Kinosternon including the Kinosternon subrubrum (Lacépède, 1788) group (=Thyrosternum Agassiz, 1857). Kinosternon pannekollops is recovered on the stem of the K. subrubrum group and is the oldest and largest member of that lineage. Kinosternon notolophus is readily differentiated from other Miocene Kinosternon in possessing a distinct dorsomedial keel on the nuchal and faint dorsolateral costal carination. The K. subrubrum group probably originated in the late Miocene savannas of the Great Plains and dispersed eastward via the Gulf Coastal Plain. An unnamed kinosternine taxon existed in the coastal plains of the eastern and southeastern United States during the Middle Miocene Climatic Optimum (with fossils from ~18 to 15 Ma), and disappeared from the region coincident with the end of that megathermal event.

The earliest fossil gray whale (Eschrichtius) from the eastern North Pacific is reported from the Lower Pleistocene Rio Dell Formation of Humboldt County, Northern California. This specimen, a tympanic bulla and posterior process, is identical in morphology to extant Eschrichtius robustus and differs from Pliocene Eschrichtius sp. from the western North Pacific (Japan). Thus, it suggests that the modern bulla morphology of the gray whale had been acquired by the Early Pleistocene. The absence of fossil Eschrichtius in the Pliocene of the eastern North Pacific may indicate that the extant gray whale lineage originated in the western North Pacific during the Pliocene before invading the eastern North Pacific during the Early Pleistocene. Further discoveries of Plio-Pleistocene gray whale fossils will help test this hypothesis and properly interpret the evolutionary history of eschrichtiid clade.

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.

Two new Early Ordovician crinoids have been discovered in Gondwanan rocks of northwest Argentina. Ramseyocrinus argentinus n. sp., among the most complete for the genus, aids in reconstructing key morphology. Ramseyocrinus is unorthodox with just four radials forming the entire cup, these articulating to five arms above and a tetrameric stem below. Evidence is presented radials comprise A, B, D, and E ray elements (C absent) with B and D radials adjoining to form a compound facet for the C arm. Thus the cup entirely lacks posterior plating; an elongate anal sac projects from the CD tegmen region alongside the C arm. Cup synapomorphies closely link Ramseyocrinus and the Middle Ordovician Tetragonocrinus; inclusion of this clade within disparids is tenuous. Quechuacrinus ticsa n. gen. and sp., increases the paleogeographic range of reteocrinid camerates, previously documented only from Laurentia. This taxon expresses synapomorphies characterizing the Late Ordovician Reteocrinus, demonstrating the antiquity of this morphotype.

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.

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.

The Zittel wing of Rhamphorhynchus muensteri is reinterpreted as preserving negative impressions of closely spaced broad flat actinofibrils that were replaced by calcite but were prepared away by the specimen’s finder. The Marsh specimen preserves positive impressions of the dorsal and ventral surfaces of the wing, which show that the skin was smooth with fine wrinkles and that actinofibrils were not on the wing surface. Based on comparisons of those specimens, the dactylopatagium consisted of dorsal and ventral skins of epidermis and dermis surrounding a common hypodermis core, and keratinous actinofibrils developed in place within the dorsal epidermis adjacent to a layer of linear collagen fibers in the dorsal dermis. The actinofibrils and linear collagen fibers together formed the main functional structure of the dactylopatagium. That structure made the dactylopatagium somewhat stiff and essentially inextensible so that it folded up along discrete fold lines that probably were genetically determined. A pneumatic retrophalangeal wedge behind the antebrachium through at least wing phalanx 3 streamlined the transition between the thick wing spar and thin patagium.

The Upper Ordovician (Sandbian–Katian) bathyurid trilobite Raymondites Sinclair is revised using new collections from Missouri and Ontario, and archival material from Illinois, Wisconsin, New York, and Ontario. Phylogenetic analysis supports monophyly of Raymondites, but recognition of this genus renders Bathyurus Billings paraphyletic. We treat Raymondites as a subgenus of Bathyurus and label the paraphylum of species traditionally assigned to the latter as Bathyurus sensu lato. Bathyurus (Raymondites) is composed of five previously named species, B. (R.) spiniger (Hall), B. (R.) longispinus (Walcott), B. (R.) ingalli (Raymond), B. (R.) bandifer Sinclair, and B. (R.) trispinosus (Wilson), and two new species, B. (R.) clochensis, and B. (R.) missouriensis; an eighth species is placed in open nomenclature. All species share tuberculate sculpture on the glabella, a relatively short palpebral lobe whose length is less than half of preoccipital glabellar length, and a pygidial outline that is well rounded posteriorly. Aside from the most basal species, B. (R.) longispinus, they also possess occipital spines and, where the pygidium is known, axial pygidial spines.

Until now, the buccinid genus Chauvetia was considered of European or West African origin, and is still endemic to these areas today. This paper describes the oldest representative of the genus, Chauvetia inopinata nov. sp., from the upper Burdigalian-lower Langhian transition Cantaure Formation of Venezuela. This surprising record suggests a New World tropical origin to the genus and subsequent immigration to the Old World before the earliest known Old World record, which is upper Tortonian. We postulate that this pre-late Tortonian (pre-8.12–7.42 Ma) dispersal of the tropical Gatunian west-Atlantic Chauvetia into the tropical East Atlantic European-West African Province most probably happened during the 10.71–9.36 Ma interval (early–mid Tortonian) during which the Circum-Tropical Current weakened, and the northward Intra-Caribbean Current had started, enhancing the Gulf Stream and the North Atlantic Current. This new data constitutes compelling evidence of a pre-Pliocene eastward dispersal of New World shallow marine organisms across the Atlantic.

Bryozoans and all biomineralized metazoan phyla extend back into the Cambrian. Pywackia Landing, 2010 is confirmed as a secondarily phosphatized, late Cambrian stenolaemate bryozoan with colonial habit; mineralized zooarium (originally calcareous); granular/rarely granular-prismatic histology of its trilamellar walls; and polymorphism shown by deep autozooecia with diaphragms and hemiphragms, axial zooecia with diaphragms, and probable nanozooecia. The irregular form of Pywackia reflects growth as a 14-hedron that could not branch and a lack of structures such as thickened walls or styles that maintain regular autozooecial spacing in later stenolaemates. Pywackia is a stem group stenolaemate with a stolon modified into a budding axial zooid and autozooid budding. It is morphologically simpler than the highly evolved late Tremadocian bryozoans of South China with features such as styles, cystiphragms, thickened zooecial walls, and massive or branching colonies. As with some bryozoans, Pywackia lacks holdfasts but has lineated living chambers and variably sized autozooecia. The late Cambrian origin of bryozoans, euconodonts, polyplacophorans, and cephalopods set the stage for the Ordovician Radiation’s complex communities. Pywackia is not a pennatulacean octocoral. It lacks both a pennatulacean axial rod histology and a budding zooid that remains confluent with daughter autozooids. Indeed, Pywackia walled off its axial zooid. Similarity of the 6- and 12-sided Pywackia zooarium with circular to 4-sided pennatulacean axes only includes calcareous composition and the general shapes of Pywackia zooaria and some Lituaria axial rods. The pennatulacean record does not extend from the Mesozoic into the Cambrian, and early cnidarians were not phosphatic. The diagnosis of Pywackia is modified.

The fossil record of early deuterostome history largely depends on soft-bodied material that is generally rare and often of controversial status. Banffiids and vetulicystids exemplify these problems. From the Cambrian (Series 3) of Utah, we describe specimens of Banffia episoma n. sp. (from the Spence Shale) and Thylacocercus ignota n. gen. n. sp. (from the Wheeler Formation). The new species of Banffia Walcott, 1911 shows significant differences to the type species (B. constricta Walcott, 1911) from the Cambrian (Series 3, Stage 5) Burgess Shale, notably in possessing a prominent posterior unit but diminished anterior section. Not only does this point to a greater diversity of form among the banffiids, but also B. episoma indicates that the diagnostic median constriction and crossover of either side of the body are unlikely to be the result of taphonomic twisting but are original features. Comparisons extend also to the Cambrian (Series 2) Heteromorphus Luo and Hu in Luo et al., 1999 and, collectively, these observations support an assignment of the banffiids to the vetulicolians. The new taxon T. ignota represents the first discovery of a vetulicystid from beyond China and also significantly extends its stratigraphic range from Series 2 Cambrian into Series 3 Cambrian. Despite overall similarities in bodyplan, T. ignota differs from other vetulicystids in a number of respects, notably the possession of an anterior zone with broad tentacle-like structures. This new discovery is consistent with the vetulicystids representing stem-group ambulacrarians.

Phyllocarids of the Waukesha Biota were systematically and taphonomically evaluated. Three Ceratiocaris species are present in the biota: C. macroura Collette and Rudkin, 2010; C. papilio Salter in Murchison, 1859; and C. pusilla Matthew, 1889. Specimens range in completeness from nearly complete, including the cephalic to caudal regions, to isolated telsons and furcae. Evidence of Salter’s position is present in only three specimens. Relatively complete specimens are interpreted to represent corpses, rather than molts; whereas specimens including only the pleon and caudal region, or caudal region, and specimens with evidence of Salter’s position likely represent exuviae. Specimens are preserved essentially as compression fossils exhibiting two types of preserved cuticle: brown inner cuticle, which tends to be impressed over the topography of bedding planes on which specimens are preserved, and blue-gray phosphatized cuticle exhibiting sub-millimeter scale relief. Cuticle phosphatization likely occurred during early diagenesis. The presence of characteristic near-shore species and C. pusilla, only known from turbidite facies, interpreted to possibly represent a marine trough, suggests that the Waukesha phyllocarid assemblage might represent a transported assemblage, rather than a biota, or that C. pusilla from the Jones Creek Formation was transported basinward in sediment gravity flows.

The Antarctic pelagornithid record is restricted to few isolated remains from the Eocene of Seymour Island in the Antarctic Peninsula. Here we report the oldest Antarctic pseudo-toothed bird. It is represented by an incomplete humerus lacking its proximal end, which comes from the lower Eocene levels of the La Meseta Formation (Seymour Island). This new specimen facilitates a review of all known pelagornithids from this continent. Antarctic pelagornithids were classified into two morphotypes that exhibit a mix of putative plesiomorphic and derived characters. Considering the worldwide pelagornithid record and according to estimated wingspans, four approximate size-types were identified. The oldest Antarctic specimens (two fragmentary humeri, middle Ypresian) were assigned to morphotype 1 and correspond to the large size-type. The younger materials (Bartonian/?Priabonian) here assigned to morphotype 2 (some cranial remains, fragmentary tarsometatarsus and humerus) correspond to the giant size-type and represent one of the largest known pseudo-toothed birds. Even though species level phylogenetic affinities of Pelagornithidae remain poorly resolved, three key evolutionary events can be recognized: (1) the disappearance of Dasornis in the Early Eocene and the appearance of more advanced forms with a trend to the specialization of large soaring capacity, (2) the origin of Pelagornis sensu lato species in the early Oligocene, and (3) the appearance and dominance of a highly specialized terminal group at Mio/Pliocene time span.

Tolypelepis mielnikensis n. sp. from a core sample of the Late Silurian (Pridoli) succession in Mielnik, Poland shares tolypelepidid features such as a subdivision of the dorsal shield into epitega, and ornamentation of short dentine ridges grouped into scale-like units with a coarser, higher median ridge encircled by narrower and lower ridges. A constriction of the dorsal shield anterior to the orbit level with the orbital notches significantly deeper than in other tolypelepidids discriminates it from other Tolypelepis species.

Rhinoceroses were important in North American mammal faunas from the late middle Eocene to the Miocene, but the group’s poor sampling outside the High Plains and eastern Rocky Mountain regions during their early evolution significantly hinders understanding of their biogeography. This limited geographic sampling is particularly true of early–middle Oligocene time, with the vast majority of Whitneyan localities occurring in the White River Badlands of South Dakota. Thus, any rhinocerotid from outside the High Plains during this period is significant. We describe two new rhinocerotid specimens from the middle Oligocene Steamboat Formation of the northeastern Warner Mountains of California. Although the Steamboat Formation is well known for fossil plants, this is the first report of mammalian fossils from the area: an isolated lower molar recovered in 1974 but not previously described or illustrated, and a mandibular fragment recovered approximately 20 years later and bearing two molar teeth, most likely pertaining to the same taxon and horizon. The lack of distinctive morphological characters suggests both fossils be conservatively referred to Rhinocerotidae incertae sedis. Based on published tooth measurement data, Trigonias osborni represents the closest size match, but that species is currently only known from the Chadronian. Similarly, the Whitneyan taxon Diceratherium tridactylum is approximately the right size, but is currently only known from the High Plains and its presence in California would expand its geographic range substantially. Of greatest importance here is that sediments of the eastern Warner Mountains may represent a largely unexplored locale for early–middle Oligocene fossil vertebrates, and may yield important future finds.

The distribution of all recognized biotic elements was mapped on five extensive surfaces of the Middle Triassic Guanling Formation exposed in quarries near Luoping, Yunnan Province, China. A 0.5 m2 grid was overlain on the surfaces, and all recognizable fossils were located by placing them in one of nine quadrants within the grid. A total of 240 m2 were mapped, and each specimen observed was recorded as one of 15 categories, subsequently grouped as pelagic, benthic, and other (bone, trace fossils, algae). The pelagic component, fish, thylacocephalans, and mysidaceans, dominated all layers. The benthic component was sparse on all surfaces; epifaunal, vagrant organisms were the dominant forms, suggesting that the substrate was unsuitable for infaunal and sessile epifaunal organisms. Shrimp and bivalves dominated the benthic organisms. Two of the surfaces were overwhelmingly dominated by mysidaceans, and one was dominated by thylacocephalans, suggesting that their remains documented periodic mass kills of swarming, pelagic organisms. Scanning electron microscope analysis of the bedding surfaces revealed nothing remarkable about the sediment, suggesting that the cause of death of the organisms was likely due to an event within the water column, possibly an algae bloom, not recorded in the sediment record.

Bulk maceration of unconsolidated Potomac Group sediments collected from 12 samples of middle–late Albian and early Cenomanian age on the Elk Neck Peninsula, Maryland, yielded 14 genera and 18 species of megaspores. The identified megaspores have affinities to both heterosporous ferns, e.g., Arcellites and Molaspora, and to heterosporous lycopsids, e.g., Erlansonisporites, Minerisporites, and Paxillitriletes. Morphological variation within species is high, and most morphotypes differ from established taxa in one or more characters. Two new species—Dijkstraisporites praetextus and Verrutriletes diversus—are proposed. The composition of these middle–late Albian and early Cenomanian floras is a mixture of taxa previously recorded from Aptian and Santonian floras in North America. In addition, a fragmentary strobilus of selaginellalean affinity containing a megaspore and microspores is described.

Newly discovered mandibles and lower dentition of the middle Eocene rodent Thisbemys brevicrista from the Green River Basin, Wyoming, are the basis for a species re-diagnosis. Previously, only the upper dentition and a partial maxilla of T. brevicrista were known from Br3. New specimens from Br2 now include the lower molars, additional upper molars, and maxillary fragments including a partial zygomatic arch that preserves the relationship of the arch to the first upper molar. In addition, the presence of T. brevicrista at Br2 documents the co-existence of T. brevicrista with T. perditus, T. nini, T. plicatus, and T. corrugatus. Formerly, the latter two species were differentiated primarily using stratigraphy. Now, morphology and size can also be used. Thisbemys brevicrista is intermediate in size between T. plicatus and T. corrugatus, and can readily be distinguished from these species based on unique features of the upper and lower molars, which include an additional loph on the two anterior upper molars and a complete metalophid on m1-3. The original type specimen of T. brevicrista appears to be lost, thus a neotype is designated as part of the re-diagnosis. Discovery and description of the lower dentition and mandibles of T. brevicrista clarifies the alpha taxonomy of this species, and increases its utility for studies of phylogenetic relationships and for documenting Eocene mammalian diversity patterns.