Baiotomeus is a new genus of ptilodontid multituberculate from the late Torrejonian Land-Mammal Age (late middle Paleocene) of western North America. Baiotomeus douglassi (Simpson), the type species, has been assigned, at one time or another, to Ptilodus, Mimetodon, and Neoplagiaulax. In addition, a second, new species, B. lamberti, from three localities in the Medicine Rocks area of southeastern Montana is reported here. The Medicine Rocks localities are tentatively assigned a latest Torrejonian age, younger than localities yielding B. douglassi and younger than previously suggested on the basis of plesiadapid primates.

Multituberculates appear to have attained their highest species richness during the Torrejonian Land-Mammal Age, but the discovery of B. lamberti illustrates that our knowledge of multituberculate diversity is incomplete from even that interval of time.

The genus Neocricetodon represents one of the most diverse radiations of extinct cricetines. Its early evolution remains unclear, mainly owing to the incomplete fossil record. One of the earliest and least known species of this genus is N. moldavicus described from the early late Miocene localities Bujor 1 and Calfa, Moldova. We reexamined the type material of this species and compared it with other species of Neocricetodon. Despite its old geological age, N. moldavicus demonstrates rather advanced dental morphology including the anterocone of M1 being deeply split; mesolophs and mesolophids partially reduced; and the labial spur of the anterolophule, ectomesolophids, and lingual anterolophid of m2 lacking. The phylogenetic analysis of 15 Neocricetodon species based on 22 dental characters revealed three synapomorphies for the genus: presence of the M1 labial anterolophule, the four-rooted M2, and presence of the labial anterolophulid of m1. “Kowalskia cf. schaubi” from Rudabánya and “Kowalskia sp.” from Vösendorf, formerly considered as the earliest finds of Neocricetodon, do not possess these characters and rather represent the genus Democricetodon. Our study also suggests that Kowalskia complicidens is a member of Sinocricetus, and that N. neimengensis and N. zhengi are junior synonyms of N. polonicus. The recognition of N. moldavicus as the earliest member of the genus within the clade containing the species of Neocricetodon from France and Spain supports the hypothesis of the Eastern European origin of the Western European Neocricetodon species.

Treeshrews are small, Indomalayan mammals closely related to primates. Previously, three-dimensional geometric morphometric analyses were used to assess patterns of treeshrew lower second molar morphology, which showed that the positions of molar landmarks covary with intraordinal systematics. Another analysis used dental topographic metrics to test patterns of functional dental morphology and found that molar curvature, complexity, and relief were an effective means for examining patterns of variation in treeshrew dietary ecology. Here, we build on these analyses by adding two fossil taxa, Prodendrogale yunnanica Qiu, 1986 from the Miocene of China and Ptilocercus kylin Li and Ni, 2016 from the Oligocene of China. Our results show that Pr. yunnanica had a dental bauplan more like that of a tupaiid than that of a ptilocercid, but that the extant tupaiids, including Tupaia and Dendrogale, are more similar to one another in this regard than any are to Prodendrogale. This is contrary to our expectations as Prodendrogale is hypothesized to be most closely related to Dendrogale. Ptilocercus kylin, which has been proposed to be the sister taxon of Pt. lowii Gray, 1848, is characterized by dental morphology like that of Pt. lowii in crest and cuspal position but is interpreted to have been more frugivorous. It has been claimed that Ptilocercus has undergone little morphological change through time. Our results suggest that Pt. kylin was more ecologically distinct from Pt. lowii than previously proposed, providing a glimpse into a more complex evolutionary history of the group than had been inferred.

A unique monospecific bonebed of rhinophrynid anurans was recently discovered in the Wagon Bed Formation (Middle Eocene, Uintan), Hot Springs County, Wyoming. The bonebed occurs on a single bedding plane within a thin sandstone layer. This unit is part of a nearshore facies of a calcium carbonate-rich lake in which the water was warm, shallow, and quiet at the site of the mortality layer.

A representative area of this bonebed, approximately 450 square centimeters in size, provides the basis for this taphonomic and paleoecologic study. This area contains approximately 600 bones and at least 19 individuals are represented. Skeletons are nearly completely disarticulated but somewhat associated, bone modification features are absent, a slight preferred orientation of the linear bones is present, and many of the lighter, less dense skeletal elements are underrepresented. Scavengers probably contributed to disarticulation of the skeletons. Bone depletion occurred by a combination of the action of scavengers, weak currents, and the sloughing off of body parts as the carcasses floated. The assemblage was not subjected to extensive winnowing by currents.

All of the specimens within this assemblage represent young adults. Because the frogs are all of the same ontogenetic age and the deposit shows no signs of time averaging, the assemblage is interpreted as the result of catastrophic death, possibly by disease, of one age class. Either a population of frogs inhabited the site where the mortality layer formed or the carcasses floated into it.

As first designated by Böse, the Albian-Cenomanian (Lower Cretaceous-Upper Cretaceous) boundary in northern Mexico and Texas is selected at the base of the ammonite zone of Plesioturrilites brazoensis (Römer). This boundary seems to best agree with boundaries selected for North Africa and Europe, but in North America it may not be the optimum boundary for paleontologists working with foraminiferans.

Systematic revisions and revised stratigraphic occurrences are made to Aorocrinus, Dorycrinus, Macrocrinus, Paradichocrinus, Strotocrinus, and Uperocrinus from the Osagean and Meramecian stratotype region in Iowa and Missouri. Systematic revisions include the assignment of Batocrinus procerus Miller and Gurley as a junior synonym of Macrocrinus mundulus. Batocrinus heteroclitus Miller and Gurley, B. vicinus Miller and Gurley, and B. stelliformis Miller and Gurley are assigned to Uperocrinus heteroclitus n. comb. The concept of Aorocrinus spinosulus (Hall) did not match characteristics of the holotype. Consequently, the appropriate name for this concept is Aorocrinus kelloggi (Worthen) n. comb., and A. spinosulus is assigned to Dorycrinus mississippiensis as a junior synonym. Batocrinus strenuus is assigned to Aorocrinus strenuus n. comb.?; and Strotocrinus glyptus is regarded as the valid name for the only species recognized in this genus.

These systematic revisions result in the restriction of Strotocrinus glyptus to the middle Osagean Burlington Limestone, and extension of Aorocrinus, Dorycrinus, Macrocrinus, and Uperocrinus into the Meramecian upper Warsaw Formation.

A new monospecific family of asteroids (Echinodermata) is based on Eukrinaster ibexensis n. gen. and sp. from the Lower Ordovician of Utah and Nevada. Eukrinaster, Arenig in age, is one of the earliest of known asterozoans. The new, relatively well-preserved fossils yield important information on character state distribution that will be useful for the interpretation of phylogenetic relationships among the three asterozoan classes, the Somasteroidea, Ophiufoidea, and Asteroidea. In addition, overall form is suggestive of certain living asteroids: to the extent that form equates with function, similarities suggest ecologic parallels in these only distantly related asteroids inhabiting ecologically distinct worlds.

Representatives of the family Inaniguttidae dominate a diverse and well-preserved radiolarian assemblage from Kazakhstan. The fauna was extracted from a limestone sample of the Shundy Formation, a limestone sequence that accumulated on the slope of a carbonate platform and which crops out in the Aksuran Mountains (North Balkhash Region). The family Inaniguttidae is represented in the studied assemblage by five genera and 14 species (including two new species, Triplococcus aksuranensis and Inanibigutta maletzi). The genus Triplococcus is particularly abundant, representing half of the Inaniguttids in the studied assemblage. Based on the presence of species Haplentactinia juncta, the fauna can be correlated with the upper Darriwilian Haplentactinia juncta–Inanigutta unica assemblage. Identified trilobites (Endymionia semielliptica and Porterfieldia sp. aff. P. delicata) found in the same sample also suggest a late Darriwilian age, which agrees with the age suggested previously by graptolites.

One of the rarest pterosaurs from the Upper Jurassic Solnhofen Limestone of southern Germany is Pterodactylus suevicus. Only two specimens are known: the holotype, consisting of a virtually complete skeleton described by Quenstedt (1855); and a second specimen, consisting of only postcranial elements described by Wagner (1858) and lost during World War II (Wellnhofer, 1970). Seeley (1870) noted that P. suevicus differed from P. antiquus, the type species of Pterodactylus, in a number of significant points. Therefore, he placed P. suevicus in a new genus, Cycnorhamphus. Seeley (1870:111) gave the following diagnosis of Cycnorhamphus:

The character “nares very small” was the result of a misinterpretation of depressions on the premaxillae that probably resulted from crushing, and “middle hole of the skull” referred to the confluent naris and antorbital fenestra, which Seeley apparently considered the antorbital fenestra alone.

Two new genera, Barrandecirrus (Porcelliinae) and Pernericirrus (Agnesiinae), from Upper Silurian marine sediments of the Prague Basin (Barrandian area, central Bohemia) are described. Both these genera belong to the family Porcelliidae and represent the oldest representatives of the superfamily Cirroidea (Vetigastropoda). The sinistrally coiled teleoconch of Barrandecirrus filiformis (Perner) suggests that the pseudobilaterally symmetrical teleoconch of the younger genera of Porcelliinae (Porcellia and Coloniacirrus) is a secondary shell character that originated during post-Silurian evolution of this group. In addition, the sinistral, low trochospiral teleoconch of early Agnesiinae [Pernericirrus sinistorsus (Perner) and Agnesia costata (Goldfuss)] as well as the asymmetrical position of the selenizone and the sinistral teleoconch in early Porcelliinae (Barrandecirrus filiformis) support the opinion that both Porcelliinae and Agnesiinae arose from the same stock. Data presented also suggest that the superfamily Cirroidea evolved during the Silurian or earlier, and it has developed parallel to and independently of other larger groups of the Vetigastropoda such as the Pleurotomarioidea and the Trochoidea.

Permian faunal affinity in the Lhasa Block plays a critical role in reconstructing its paleogeographic evolution. Cisuralian and Guadalupian faunas have been described from the Lhasa Block, but very few Lopingian (late Permian) brachiopods have been reported so far. In this paper, a new diverse brachiopod fauna consisting of 17 species of 17 genera and an unidentifiable Orthotetoidea is described from the uppermost part of the Xiala Formation at the Aduogabu section in the central part of the Lhasa Block. The age of this fauna can be assigned to the Changhsingian (late Lopingian) as indicated by the associated foraminifers Colaniella parva (Colani, 1924) and Reichelina pulchra Miklukho-Maklay, 1954. Characteristic brachiopods include Spinomarginifera chengyaoyenensis Huang, 1932, Haydenella wenganensis (Huang, 1932), and Araxathyris cf. dilatatus Shen, He, and Zhu, 1992. They also generally suggest a Changhsingian age. Paleobiogeographically, this fauna is uniformly composed of typical Tethyan elements represented by Spinomarginifera Huang, 1932 and Haydenella Reed, 1944, and some cosmopolitan elements, but no typical cold-water taxa of Gondwanan affinity. This is in contrast to the contemporaneous brachiopod faunas from the Tethys Himalayan region that are characterized by typical cold-water taxa of Gondwanan affinity, e.g., Costiferina indica (Waagen, 1884), Retimarginifera xizangensis Shen et al., 2000, Neospirifer (Quadrospina) tibetensis Ding, 1962. Thus, it is strongly indicative that the Lhasa Block had drifted into a relatively warm-water regime during the Changhsingian. An analysis of the paleobiogeographic change of brachiopods in the Lhasa Block throughout the entire Permian further suggests that the Lhasa Block probably had rifted away from the northern peri-Gondwanan margin between the latest Cisuralian and middle Guadalupian, that is, the Neotethys Ocean had opened before middle Guadalupian.

Glyptospira is a small, highly ornamented, turriteliform gastropod found in the Lower Permian of the southwestern United States. Two species, Glyptospira cristulata Chronic and G. arelela Plas, have been previously described from the Kaibab Formation, Arizona, and the Bird Spring Group, Arrow Canyon Range, Nevada, respectively. The genus is most diverse in the Wolfcampian Hueco Formation of West Texas and southern New Mexico and the Colina Limestone of southeastern Arizona. This contribution describes four new species of Glyptospira from the southwestern United States: two bicarinate forms, G. huecoensis and G. turrita, and two tricarinate forms, G. tricostata and G. cingulata.

A phylogenetic analysis of all known species of Glyptospira was performed using qualitative characters for which transformation series could be established and two quantitative characters for which transformation series could not be established. The phylogenetic results provided the best available hypothesis of the evolutionary history of the genus.

A diverse, previously unknown fauna with Skenidioides and other small brachiopods, ostracodes, trilobites, and corals has been dated as gronbergi Zone on coexisting conodonts. Conodonts date the Leptocoelina globosa fauna as serotinus Zone. Cymostrophia seca, Strophodonta luxor, and Atrypa kobar are new species. These assignments and new occurrences allow retabulation of most Emsian brachiopod ranges in Nevada.

Plotting of provincial, endemic, and cosmopolitan brachiopod genera on a time vs. percent graph shows that the shift through time of Nevada faunas from Eastern Americas Realm to Old World Realm took place gradually during Emsian transgression. Endemic genera were prominent during early phases of Devonian transgression.

Acid etching combined with scanning electron microscopy (S.E.M.) accentuates a variety of conodont microstructural patterns as compared to unetched specimens. External and internal organic layers surrounding apatitic lamellae are found with internal organic layers apparently thinner than their external counterparts. This may imply partial removal of the outermost organic layer prior to secretion of the next lamella. Etching also provides evidence of internally preserved striate ornament. Polygonal etch artifacts and zones of crystallites aligned in small areas are interpreted as possible sites for apatite biomineralization.

Scanning electron microscopy of tests of Triticites ventricosus and Schwagerina sp. shows that the microgranular wall was secreted rather than agglutinated. Grains range in size from 0.5 to 6.0 μm, but grains larger than 4 μm are rare. Evidence that grains were secreted includes tight packing, uniform size and shape, and apparently homogeneous composition. Furthermore, scanning electron microscopy confirms the perforate nature of the antetheca and the nature of the keriothecal wall. Alveoli taper toward the tectum and pass through the tectum as tiny pores, enhancing communication between chambers and with the external environment.

The traditional model for the addition of chambers is rejected. Three ways in which new chambers may have been added to the test that are consistent with observations made here: 1) The antetheca may have thickened differentially, creating a substrate to which the keriotheca of the new chamber was attached; 2) Part of the tectum, septum, and keriotheca of the previous chamber may have been resorbed before calcite forming the new chamber was secreted, perhaps necessary because the tectum was an unsuitable substrate on which to attach the keriotheca of the new chamber; 3) A combination of the above may have occurred wherein the antetheca thickened differentially and was resorbed locally, providing a suitable substrate on which to attach the keriotheca of the new chamber. The last model is favored here because it best explains the shape of the septa and the configuration of the keriotheca of the chambers of most specimens. Nevertheless, the other two models are consistent with the morphology of some specimens.

The evolutionary history of the major boring-bivalve superfamily Pholadoidea remains unclear. Opertochasma somaensis n. sp., preserved in situ in fossilized wood from upper Kimmeridgian to lower Tithonian strata within the Upper Jurassic shallow marine Nakanosawa Formation, northeast Japan, is described. This new species represents one of the oldest body fossils of pholadoidean boring-bivalves and the first fossil record from the Jurassic in the circum-Pacific regions. The authochthonous occurrence in fossilized wood, the presence of microscopic file-like sculpture on the anterior shell slope, the short clavate burrow, and other shell features demonstrate that O. somaensis n. sp. was a filter-feeding, obligate wood-borer with anterior-boring locomotion, and also that the complex shell morphology unique to Pholadoidea was established by the Late Jurassic. The documentation of the new species and taxonomic review on the Jurassic species previously described, show that the superfamily Pholadoidea was widely distributed along the Northern Hemisphere middle latitudes in the latest Jurassic. The Pholadoidea likely evolved by exploiting woody substrata which had become abundant during the Late Jurassic with floral diversification in the middle latitudes. It is notable that the xylophagous mode of life, referable to modern Teredinidae and Xylophagaidae, was most probably established in the Jurassic and provided an important background for the establishment of chemosynthesis-based, sunken wood-associated communities.

The Late Cretaceous white chalk of the Isle of Rügen, northeastern Germany, yields a highly diverse marine floral and faunal assemblage with more than 1,400 described species, including pennatulacean corals. All the new collected material, composed of fragments of the axial rods, belongs to ‘Graphularia’ quadrata Voigt, 1958, which was revised, and a new species, ‘Graphularia’ rugia. Analyses of the microstructure of axial rods of modern and fossil sea pens facilitate the discussion of the systematic relationships of the fossil material. ‘Graphularia’ quadrata shows an affinity to the Funiculinidae, whereas the new species ‘Graphularia’ rugia resembles the axial structure of the Pennatulidae.

Rare remains of hadrosaurian dinosaurs previously reported from the Maastrichtian Javelina Formation of West Texas had been attributed tentatively to either Edmontosaurus or Kritosaurus. Three recently recovered specimens include substantial skull parts and postcranial skeletal elements sufficient to recognize three distinct hadrosaurs. Two species are found in the lower part of the Javelina Formation; one of these is identified as Kritosaurus sp., confirming the earlier referral of specimens to this taxon. The most complete of these specimens combines features thought to be diagnostic of both K. navajovius Brown, 1910 and ‘Naashoibitosaurus’ ostromi Hunt and Lucas, 1993 and exhibits some unique attributes such that its specific identity remains uncertain. A second species, documented by a single specimen found near the base of the Javelina Formation, is inadequate to confidently identify but appears to represent a ‘solid-crested’ saurolophine with frontals having upturned processes along the midline, similar to those that brace the posterior side of the narial crest in Saurolophus. A third hadrosaur is represented at a bonebed in the uppermost part of the Javelina Formation. Its remains are sufficient to justify designation as a new species ?Gryposaurus alsatei. The skull roof elements are similar to those in species of Gryposaurus, and although no parts of the narial crest are preserved, the bordering elements indicate that ?G. alsatei was a ‘flat-headed’ saurolophine. Referral of ?G. alsatei to Gryposaurus would constitute a significant temporal range extension for the genus into late Maastrichtian time, and if correct, this long-lived lineage of hadrosaurs persisted nearly to the end of Cretaceous time in West Texas. ?G. alsatei was a contemporary of Edmontosaurus, the sole terminal Cretaceous hadrosaur in the northern Great Plains region, and neither possessed the ornate narial crest that characterized many earlier hadrosaurs.

The Sesong Formation is a member of the Taebaek Group, Korea, which extends from late Cambrian Series 3 to middle Furongian in age. Recent studies on the trilobites of the Sesong Formation have contributed significantly to the revision of the biostratigraphy. However, trilobites in the lower part of the formation, which may include the “Stephanocare Zone”, have remained essentially overlooked since the establishment of the biozone, making it difficult to correlate with the equivalent biozones of North China. Here we report trilobite faunas from the lower part of the Sesong Formation in two different sections, the Seokgaejae and the Jikdong sections, which yield two species of Jiulongshania among other species. Species of Jiulongshania have been known to occur successively in North China, so are useful for detailed correlation. Specimens of Stephanocare richthofeni are fragmentary and rarely occur in association with Jiulongshania regularis, while Jiulongshania species occur throughout the studied intervals. Accordingly, it is reasonable to extend the previously established Jiulongshania Zone of the uppermost part of the underlying Daegi Formation into the lower part of the Sesong Formation. By doing so, the Jiulongshania Zone is correlated with the Blackwelderia Zone of North China with confidence. The lowermost part of the Sesong Formation in the Jikdong section yields a fauna including J. regularis, which implies that the boundary between the Daegi and Sesong formations is diachronous within the Taebaeksan Basin. The Daegi/Sesong formation boundary in Korea is comparable to the Zhangxia/Gushan boundary in North China in that it displays an abrupt change from a carbonate-dominant facies to a shale-dominant facies. The correlation employing the Jiulongshania species indicates that the facies shift occurred significantly earlier in Shandong, North China than in the Taebaeksan Basin, Korea.

A new species of Ptychocrinus, Ptychocrinus adamsensis, and dendrocrinid, genus and species undetermined, are described from the Lower Silurian (Llandovery) Brassfield Formation of Adams County, Ohio. Unlike previously recognized Ptychocrinus species, P. adamsensis has biserial arms. Accordingly, the generic concept of Ptychocrinus is broadened. Ptychocrinus adamsensis is the youngest North American species of Ptychocrinus. Ptychocrinus is not known from the Brassfield fauna that has been previously described from the Greene–Montgomery County area of Ohio.