Two new, extinct taxa of peccaries from upper Miocene deposits of the western Amazon Basin provide the first data documenting the presence of these North American mammals in South America in the Miocene. One, Sylvochoerus woodburnei n. gen. n. sp., is allied morphologically to Tayassu pecari, whereas the second, Waldochoerus bassleri n. gen. n. sp., is more similar to Pecari tajacu. Both new taxa reflect an intermediate position between middle Miocene peccaries and modern Tayassu and Pecari. The specimens reported here were unstudied, but when collected they were referred to living species of Tayassu and Pecari based on their general similarity to species of those two living genera, and they were dated to the Pleistocene, presumably based on a long–standing model of the Great American Faunal Interchange. The presence of peccaries in South America at approximately the same time that South American ground sloths began appearing in upper Miocene deposits of North America, and soon after the appearance of gomphotheres in South America, indicates that dispersal between the Americas was earlier and involved more taxa than previously interpreted. Molecular divergence data are consistent, in part, with a late Miocene dispersal of peccaries to South America.

A new early Danian gastropod assemblage contained in the Roca Formation of Río Negro Province was analyzed. Eleven species are described and illustrated, the new genus Rocalaria is created, and six new species are recognized: Gyroscala daniana, Heteroterma carmeloi, Microfulgur concheyroae, Sulcobuccinum prominentum, Cidarina lenzaniyeuensis, and Rocalaria alani. The present research includes the first mention of Sulcobuccinum d'Orbigny, 1850, Priscoficus Conrad, 1866, Cavoscala Whitfield, 1892, Microfulgur Finlay and Marwick, 1937, and Cidarina Dall, 1909, for the Danian of Southern South America; the new record of Austrophaera Furque and Camacho, 1949, Fusinus Rafinesque, 1815 and Heteroterma Gabb, 1869 in northern Patagonia; and the oldest Paleogene record for the genus Gyroscala de Boury, 1887. The presence of the study assemblage in northern Patagonia indicates a more complex paleobiogeographic pattern for the area than previously thought, as shown by the record of endemic genera, cosmopolitan taxa, elements with Tethyan/ Indo-Pacific affinities, and genera related with “Wangaloan” faunas of the Paleocene of New Zealand.

Fossil echinoderms are a rich source of information concerning biotic interactions. In this study we analyzed the premortem encrustation of the highly specialized Middle Devonian rugose corals Aspasmophyllum crinophilum and ?“Adradosia” sp. on camerate crinoid stems. Aspasmophyllum infested living crinoid stems by sclerenchymal outgrowth that formed a skeletal ring but ?“Adradosia” sp. encrusted the stems rapidly, without building a ring. These coral-crinoid biocoenoses indicate a settlement advantage for the rugose corals within densely populated communities of the lower Givetian. The corals could be interpreted as large epizoozoans that benefited as secondary tierers reaching relatively high tiering levels. It also suggests the ability for the affected crinoids to repel the coral by overgrowing the corallite with a local increased stereomic growth. Because the crinoid axial canals are not penetrated, the corals cannot be considered as predators or parasites of crinoids. Therefore, the described biocoenosis is interpreted as commensalism. The species A. crinophilum is redescribed, and a neotype is defined, because of the loss of the initial types. Two types of ichnofossils can be attributed to the premortem encrustation of both corals. They are described as Ostiocavichnus n. ichnogen. and are attributed to the stereomic response of the infested hosts. These swellings are characterized as either elliptical (Ostiocavichnus ovalis n. ichnogen. n. ichnosp. due to the assumed reaction of A. crinophilum) or subcircular concavities (O. rotundatus n. ichnogen. n. ichnosp. due to the reaction of ?“Adradosia sp.”).

The Paleozoic to Mesozoic grade ‘Protozygoptera’ is revised. It appears to be composed of two main lineages, namely the superfamily Permagrionoidea, and the Archizygoptera. The latter taxon forms a monophyletic group together with Panodonata (=crown-Odonata plus their closest stem-relatives). Therefore, the ‘Protozygoptera’ as previously understood is paraphyletic. Diagnostic characters of the ‘Protozygoptera’, Permagrionoidea, and Archizygoptera are re-evaluated. The Permolestidae is considered as a junior synonym of the Permagrionidae. The following new taxa are described: Permolestes sheimogorai new species, Permolestes soyanaiensis new species, Epilestes angustapterix new species, Solikamptilon pectinatus new species (all in Permagrionidae); Lodeviidae new family (for Lodevia); Luiseiidae new family (including Luiseia breviata new genus and species); Kennedya azari new species, Kennedya pritykinae new species, Kennedya ivensis new species, Progoneura grimaldii new species (all in Kennedyidae); Engellestes chekardensis new genus and species (in Bakteniidae); and Azaroneura permiana new genus and species (in Voltzialestidae). The Kaltanoneuridae and Oboraneuridae are revised. The evolution of protozygopteran Odonatoptera during the transition from the Permian to the Triassic is discussed. The larger taxa of the permagrionoid lineage apparently did not cross through the Permian–Triassic boundary, unlike the more gracile Archizygoptera. This last group shows a remarkable longevity from the late Carboniferous to the Early Cretaceous. It also presents a great taxonomic and morphological stability, with genera ranging from the Permian to the Triassic, and a wing venation pattern nearly unchanged from the late Carboniferous to the Late Triassic. The mass extinction at the end of the Permian period seemingly had a minor effect on these tiny and delicate insects.

Crinoids were first reported from the Cuyahoga Formation in northeastern Ohio by James Hall in 1863. However, these crinoids have not been re-examined in detail since the late nineteenth century. With the restudy of classical and more recent collections, ten (nine camerate and one disparid) species-level taxa are recognized from the late Kinderhookian Meadville Shale Member, Cuyahoga Formation, including the camerates Amphoracrinus viminalis (Hall, 1863); Aorocrinus helice Hall, 1863; Aorocrinus meyeri n. sp.; Aryballocrinus martini n. sp.; Cusacrinus daphne (Hall, 1863); Platycrinites s.l. contritus (Hall, 1863); Platycrinites s.l. graphicus (Hall, 1863); Platycrinites s.l. lodensis (Hall and Whitfield, 1875); and Platycrinites s.l. burkei n. sp. In addition, Halysiocrinus sp. is the first disparid reported from this fauna. Platycrinites s.l. bedfordensis (Hall and Whitfield, 1875) is designated a nomen dubium. Growth is evaluated for Aorocrinus helice and Cusacrinus daphne, which had contrasting development. The growth of the Aorocrinus helice calyx was largely not allometric but that of the primaxil plate was, suggesting the arms may have grown allometrically. In contrast, much of the calyx of Cusacrinus daphne displayed allometric growth.

A very early juvenile specimen of Hypselocrinus hoveyi with arms and partial column attached is utilized to examine the growth in this Mississippian advanced cladid crinoid. The aboral cup height of this specimen is 4 mm. In contrast to results reported in previous studies of crinoids, Hypselocrinus hoveyi grew with a combination of allometric and isometric growth. Different plates of the aboral cup grew with a combination of growth modes, and arms grew with allometric growth or relative change in shape that was not strict allometry.

Three new archisargid species referred to one new genus, Flagellisargus sinicus, F. venustus and F. robustus, are described based on three impressions from the Callovian–Oxfordian of the “Daohugou Formation” in Daohugou, Chifeng, Inner Mongolia, China. The presence of an elongated flagellum and large male genitalia places these new findings with the distinct but rare archisargid flies. The systematic position of Origoasilus pingquanensis Zhang et al., 2011 is reassessed, placing it with Archisargidae within Archisargoidea rather than Asiloidea. The Origoasilidae is a junior synonym for Archisargidae.

A number of immature and mature exoskeletons allow the first detailed description of the ontogeny of the early Cambrian redlichiid trilobite Metaredlichia cylindrica, from black shale of the Shuijingtuo Formation in Hubei Province, South China. The material includes numerous complete protaspides, within which two stages can be differentiated according to the appearance of a shallow furrow that separates the protopygidial area from the protocranidium. Also, identification of the subsequent ontogenetic stages, including meraspides and holaspides, depends on isolated cranidia that display prominent morphological changes such as the contraction of frontal glabellar lobe, appearance of the fourth pair of glabellar furrows, and modification of the facial suture from proparian to opisthoparian. Incorporating the whole ontogenetic sequence allows us not only to trace the developmental trends of various structures with growth, but also to assign the protaspides to their adults correctly, particularly with the help of meraspid specimens.

Ichthyosaurs represent one of the most highly specialized lineages of marine reptiles, but our understanding of the evolution of this group is based on specimens found at a surprisingly small number of stratigraphic intervals and localities. The Lower Jurassic (Toarcian) Posidonia Shale of southwestern Germany is one of the richest ichthyosaur-bearing formations in the world and has produced thousands of skeletons, including specimens with preserved soft tissue, and fetal remains inside the body cavity. The most abundant ichthyosaur genus in the Posidonia Shale is Stenopterygius. In spite of almost 200 years of research effort, the number of species in this genus is still a point of active disagreement in the literature. Here, bivariate and multivariate analyses are used to classify both articulated and disarticulated skeletons to the level of species, using measurement data from individual cranial and postcranial elements. Unlike previous classification attempts, this technique pinpoints ontogenetically conserved differences in size and proportion between the species, and so can be applied to adult, subadult, and neonatal specimens. Using this method, three species of Stenopterygius, S. quadriscissus, S. triscissus, and S. uniter are differentiated.

A new species of the staphylinid subfamily Oxytelinae is described and figured from a series of well-preserved compression fossils of the Yixian Formation (Early Cretaceous), Beipiao City, Liaoning Province, northeastern China. The species is placed in the recent genus Anotylus Thomson, 1859 based on typical morphological features for the genus as well as secondary sexual characters. The strong projection of the anterior pronotal angles is a feature also possessed by males of several recent Neotropical taxa in the genus. This is the earliest fossil rove beetle with clearly demonstrable sexual dimorphism.

Larval and juvenile growth stages of myoconchid bivalves (family Kalenteridae) are illustrated and described for the first time. Excellently preserved shells of Myoconcha crassa J. Sowerby, 1824 from the middle Bathonian (Middle Jurassic) clay/silt deposits of southern Poland reveal that the prodissoconch in this taxon is large (exceeding 350 µm in length) and characterized by a prominent, collar-like structure arising from the demarcation to the dissoconch. Similar prodissoconch morphology has not been described previously in any other bivalve genus. The large size and absence of a prodissoconch II strongly suggest a non-planktotrophic development of the larvae, indicating either simple lecithotrophy or long-term brooding and parental care for the larvae in this species. Consequently, the new discovery constitutes the earliest well-documented record of non-planktotrophic development in the Bivalvia. The shell of Myoconcha crassa is composed of an outer cross-lamellar layer and an inner complex cross-lamellar layer. This composition suggests that the Kalenteridae may be included in the Carditida rather than the Palaeoheterodonta or Anomalodesmata. The genus Pseudomyoconcha Rossi Ronchetti and Allasinaz, 1966 is rejected herein and considered as a junior synonym of Myoconcha J. Sowerby, 1824.

A new species of the Pliocene–Pleistocene flat-headed peccary, Platygonus pollenae, has been recovered latest Hemphillian (latest Miocene) localities from Nebraska, Kansas, Colorado, and Texas. It can be distinguished from other tayassuids by its distally rounded wing-like zygomatic process, and its subzygodont cheek teeth. In contrast to more derived species of Platygonus, it is much smaller in size, its molars are relatively more bunodont, the talon and talonid cusps are retained on the premolars of most individuals, and the mandibular symphysis lacks a median keel on the chin. In these characters, it is the earliest and the most primitive species of Platygonus known. It is more primitive than the typical Blancan species, or any of the species from the Pleistocene, and demonstrates the origin of this important Pleistocene mammal in the latest Miocene.

A new species of the temnospondyl tetrapod, Sclerocephalus stambergi n. sp., is described from the early Permian deposits of the Boskovice Basin in Moravia (Czech Republic). The length of the skull of the only known specimen is about 50 mm. Characters including the well-ossified quadrate, septomaxilla and scapulocoracoid, presence of the maxilla-nasal suture and a free posterolateral margin of the supratemporal suggest an early adult age. This new species of Sclerocephalus is distinguished from the others on the basis of the following characters: nasal and maxillary processes of the premaxilla of equal width; absence of the alary process of the premaxilla; distinct pointed process on the lacrimal between the maxilla and jugal; narrow interclavicle; and very peculiar tabular presenting a quadrangular, plate-like process extending from its posterolateral portion, an almost right angle between its lateral and posterior margins, and a long posteromedial process. The new species represents the smallest and possibly the most basal Sclerocephalus species. The specimen described here sheds new light on the anatomy and taxonomy of Sclerocephalus. It completes the biodiversity of the tetrapod fauna from the Boskovice Basin, and our knowledge on the evolution of the European Paleozoic temnospondyls.

The visceral skeleton (including complete mandibular, hyoid, and branchial arches) and teeth of the Lower Cretaceous hybodontid shark Tribodus limae are described based on well preserved fossil material. Jaw suspension and musculature are reconstructed, representing the first reconstruction of jaw musculature in a hybodont. The jaw suspension of Tribodus is similar to batoids and advanced galeomorphs in lacking direct cranio–palatine articulations and having skeletal jaw support by the hyoid arch alone (unlike most other hybodonts), but differs from batoids in that an intact hyoid arch is present. As in Asteracanthus and Lonchidion, the jaws do not extend to the snout, and were connected symphysially but not fused. CT scanning reveals the presence of supportive ‘trabecular cartilage’ struts in force-bearing regions of the jaws, representing the first report of these structures in an extinct chondrichthyan. Five branchial arches are present, of which pharyngobranchial, epibranchial, and ceratobranchial elements are observed although hypobranchials and basibranchials were presumably also present. A pharyngobranchial blade is present, as in some other hybodonts (e.g., Lissodus) and extant galeomorphs (e.g., Heterodontus), and the posteriormost pharyngobranchials are unfused. Tribodus is considered durophagous, based on presence of ‘trabecular cartilage’ struts and a weakly heterodont monognathic pavement dentition of flattened hexagonal teeth, as in extant myliobatoid rays. SEM examination shows that teeth of T. limae are anaulacorhize with a double layer of single crystallite enameloid (SCE), and confirms the presence of columnar osteodentine, as in other Acrodontidae.

Proetid trilobites of Lower Devonian (Pragian) age are known principally from fragmentary material from the type area in the Czech Republic and Morocco. We describe well-preserved, articulated specimens from the Ihandar Formation of the Anti-Atlas, Morocco, which include species of previously little known genera, and help to clarify their morphology. Eight new species are described: Dalejeproetus sagaouii, D. owensi, Lepidoproetus maharchianus, L. lahceni, L. splendens, Podoliproetus mirdani, P. sinespina, and Proetina ihamadii.

Twenty four species of Cancellariidae belonging to eleven genera occurring in the Neogene Bocas del Toro assemblages, Caribbean Panama, are discussed and figured. The following seven species are described as new: Cancellaria pilula n. sp., Cancellaria isabelae n. sp., Cancellaria stri n. sp., Cancellaria axelolssoni n. sp., Massyla corpulenta n. sp., Aphera trophis n. sp., Admetula valientensis n. sp. The cancellarid genus Charcolleria Olsson, 1942 is considered a synonym of Massyla H. Adams and A. Adams, 1854. Of the 24 species present in the Bocas del Toro, 12 are known also to occur elsewhere in the tropical American Neogene. This level of endemism is high, but not as high as that reported from other Tropical American Neogene assemblages, probably due to the very central geographic location within the Gatunian Province of the Bocas assemblages.

Four new species of colonial corals, one previously described coral, and two other unidentified species of coral have been recovered from the Baird Formation in the Klamath Mountains of northwestern California. The newly erected species are Heritschioides armstrongi n. sp., Pararachnastraea klamathensis n. sp., P. watkinsi n. sp., and P. kabyaiensis n. sp. These corals are associated with the fusulinids Millerella marblensis Thompson, 1944, Paramillerella Thompson, 1951, and Pseudostaffella Thompson, 1942, emend Groves, 1984, suggesting an early Atokan (Bashkirian) age. Both the coral and foraminiferal faunas bear a resemblance to those of similar age in the Brooks Range, Alaska, which could suggest geographic proximity between the two terranes at that time. These corals also represent the earliest known occurrence of the Family Durhamididae.

The Araripe Basin is the most extensive interior basin in northeastern Brazil, comprising areas of Ceará, Piauí and Pernambuco states. The Santana Formation, attributed to the Aptian–?lower Albian age of the basin, is subdivided into two members, Crato and Romualdo, which bear an abundant fossil record of plant fragments, arthropods and vertebrates, especially 3D-preserved fishes. The present study focuses on the taxonomy, ontogeny and paleoecology of two ostracode species from the Romualdo Member and the top section of the Crato Member (Ipubi layers), Harbinia salitrensis (Krömmelbein and Weber, 1971) emend. and H. alta new species. The ontogenetic series for both species are illustrated, except for the A-8 instar; H. salitrensis is also redescribed. The present work is also the first to produce quantitative information about the paleoecology of the Santana Formation based on ostracode populations. The results obtained from analyses of the population age-structure of both species, in addition to dominance (Simpson) and diversity index (Shannon) values, corroborated previous data on the studied sequence. According to these results, the strata were deposited in a limnic, low-to-moderate energy environment with salinity levels varying from oligohaline to mesohaline. The new data indicate the possibility of these environments also being hypersaline.

The first skiff beetle fossil and earliest myxophagan, Hydroscapha jeholensis n. sp., is described and illustrated on the basis of a single specimen from the Lower Cretaceous Yixian Formation at Huangbanjigou of Beipiao City, Liaoning Province, Northeastern China. Based on the combination of diagnostic characters of this specimen (e.g., minute and fusiform body, short elytra, tapered abdomen, separated meso- and metacoxae, and 3-segmented tarsi), we suggest that it is a definitive representative of Hydroscaphidae belonging to the widespread hydroscaphid genus Hydroscapha LeConte, 1874. It also represents the only impression fossil of the beetle suborder Myxophaga. This find displays great significance for shedding light on the preservation of the minute aquatic beetles, since it is the first well-preserved impression fossil reported for the suborder, rather than amber inclusion.