Two new species of Nilssoniopteris of the order Bennettitales, Nilssoniopteris hamiensis Zhao and Deng, new species and Nilssoniopteris crassiaxis Zhao and Deng, new species, are established from the Xishanyao Formation (Middle Jurassic) of Sandaoling Coal Mine in Hami, Xinjiang, China, based on leaf macromorphology and cuticular features. Nilssoniopteris hamiensis n. sp. is characterized by its varied leaf shapes and trichome bases of 1–4 cells on the abaxial epidermis. Nilssoniopteris crassiaxis n. sp. is characterized by its broad midrib (especially near the leaf base) and trichome bases of 1–3 cells on the abaxial epidermis. Both species possess unique venation patterns that are not only simple and free, but also forked and merged to form closed loops. These anastomosing veins are even more complicated in N. crassiaxis n. sp. in that the veins can fork once, twice, or even three times, the forked veins can later merge with each other or with an adjacent vein to form a closed loop, which may later further disjoin. The generic diagnosis of Nilssoniopteris is thus accordingly emended, particularly in the venation pattern. In addition, the stratigraphic and geographical distributions of all 45 Jurassic Nilssoniopteris species worldwide have been summarized and analyzed to better understand their brief evolutionary history, indicating that Nilssoniopteris might be able to grow not only in subtropical regions as the living cycads are, but also in warm climatic regions.

In this contribution, four species of Agathoxylon are described from the La Matilde Formation, Gran Bajo de San Julián and central and south-western sectors of Santa Cruz Province, Argentina. Agathoxylon agathioides (Kräusel and Jain) n. comb., Agathoxylon santalense (Sah and Jain) n. comb., Agathoxylon termieri (Attims) Gnaedinger and Herbst, and the new species Agathoxylon santacruzense n. sp. are described based on a detailed description of the secondary xylem. In this work, it was possible to construct scatter plots to elucidate the anatomical differences between the fossil species described on quantitative anatomical data. Comparisons are made with other Agathoxylon species from Gondwana. These parameters can be used to discriminate genera and species of wood found in the same formation, as well as to establish differences/similarities between other taxa described in other formations. Some localities contain innumerable “in situ” petrified trees, which allowed us to infer that these taxa formed small forests, or local forests, or small forests within a dense forest, which is a habitat coincident with the extant Araucariaceae.

A bryozoan-dominated fauna that inhabited small caves underneath a carbonate hardground is here described from the Corryville Formation (Upper Ordovician, Katian) exposed near Washington, Mason County, Kentucky, USA. The dominant bryozoan, Stigmatella personata (a trepostome), is found both growing downwards from the cave ceilings and upwards on the exposed hardground surface above. Another trepostome, Monticulipora, is a minor component of the cave fauna. There are few discernible anatomical differences between the bryozoan colonies that grew upwards in presumably well-lit waters and those that grew downwards in the gloomy caves. The pendant, cave-dwelling S. personata in some cases appears to have longer zooecial tubes than its exposed equivalent. The colonies of S. personata are rounded mounds with multiple layers formed by self-overgrowth. The overgrowths in both downward and upward growing forms are marked by thin layers of sediment infilling the upper zooecial chambers in the older portion of the colony. We suggest that biofilms developed on patches of the colony where the zooids had died. Sediment adhered to these surfaces and the colony then overgrew the patches, trapping sediment within the skeleton. The bryozoan zoaria and the carbonate hardground are extensively bored by the cylindrical ichnogenus Trypanites that occasionally contain cylindrical calcite-filled tubes similar to “ghosts” of organic materials. Bioclaustrations are present in some of the bryozoan skeletons. This cave fauna is one of few submarine examples known from the Paleozoic. It supports the hypothesis that early cave-dwelling organisms were little differentiated from their exposed counterparts.

Ten bryozoan species are described from the Andrecito and Tierra Blanca members of the Lake Valley Formation (Mississippian) of Sierra County, New Mexico, USA. One genus, with one species, is new—a cystoporate, Cystomeson sierraensis n. gen. n. sp. The bryozoans indicate quieter and deeper conditions in the Andrecito Member and more agitated and shallower conditions in the Tierra Blanca Member. The species identified in this study are endemic to North America, whereas at the generic level, the composition is rather cosmopolitan.

UUID: http://zoobank.org/fc354A60-1fbc-4e41-8b9b-bbfd65e59a71

Four new species of the methane seep-inhabiting kalenterid bivalve genus Caspiconcha Kelly in Kelly et al., 2000 are described: Caspiconcha basquensis from the late Albian of northern Spain, C. yubariensis from the late Albian of northern Japan, C. raukumaraensis from the late Albian to mid-Cenomanian of New Zealand, and C. lastsamurai from the Campanian of northern Japan. The earliest confirmed record of the genus is known from the latest Jurassic. It reached its maximum diversity in the Albian and declined in diversity and abundance through the Late Cretaceous. The youngest species, C. lastsamurai, is currently known from a single specimen only.

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Species of the megaorder Poromyata, although common and relatively diverse in Albian–lower Cenomanian Comanchean strata in Texas and northern Mexico, have been neglected as biostratigraphic markers and paleoecological indicators. Since 1852, more than a dozen species have been identified as Homomya Agassiz, order Pholadomyida, superfamily Pholadomyoidea or Pleuromya Agassiz, order Pholadida, superfamily Pleuromyoidea. Because valve morphologies of the two genera are similar in many ways, casts are difficult to separate. Statistical analysis of key morphological properties objectively defines species concepts and assesses synonymies. Eight species are retained in Homomya; four are synonymized with these. Two species are provisionally retained in “Homomya” although they differ significantly. One species is reassigned to Liopistha (Sergipemya) alta (Roemer, 1852). Pleuromya henselli (Hill, 1893) is reassigned to Panopea.

Homomyid species range from upper Aptian to lower Cenomanian of the Comanchean Series in Texas and Mexico. Their ranges vary in duration from one million years up to eight million years. These infaunal suspension feeders occupied calcareous mud and carbonate shelf substrates. Two sets of species are distinct morphotypes: a smaller-sized set of H. knowltoni Hill, 1895; H. tarrantensis Perkins, 1961; H. tlahualiloensis Perkins, 1961; and H. kellumi Perkins, 1961 and a larger-sized set of H. cymbiformis Perkins, 1961; H. austinensis Shattuck, 1903; H. vulgaris Shattuck, 1903; H. budaensis Whitney, 1911; and H. auroraensis Perkins, 1961. Two end-member morphotypes are represented by the “streamlined” Homomya knowltoni, which is an elongate, slightly inflated form with a relatively high umbo, and the cylindrical Homomya budaensis, which is a very elongate, tubular, inflated form with a very low umbo.

Five species of bivalves and two species of gastropods are described from late Selandian to earliest Thanetian wood-fall communities from the Katsuhira Formation in Urahoro Town, eastern Hokkaido, northern Japan. Three bivalves and two gastropods are new to science: Thyasira (Thyasira) oliveri Amano and Jenkins, new species, Astarte (Astarte) paleocenica Amano and Jenkins, new species, Poromya katsuhiraensis Amano and Jenkins, new species, Neverita majimai Amano and Jenkins, new species, and Biplica paleocenica Amano and Jenkins, new species. Poromya katsuhiraensis n. sp. and Neverita majimai n. sp. are the earliest records of their genus. Astarte paleocenica n. sp. is the last species before the genus disappeared from the northern Pacific region during the Eocene, only to reappear with the opening of the Bering Strait during the latest Miocene. Moreover, two bivalve species and one gastropod genus are Cretaceous relict forms: Propeamussium yubarense (Yabe and Nagao, 1928), Myrtea ezoensis (Nagao, 1938), and Biplica Popenoe, 1957. These species and other relict protobranch bivalves had wide geographical ranges in the deep sea during the Cretaceous, which helped them to survive the end-Cretaceous mass extinction. The chemosynthesis-based species Bathyacmaea? sp., Myrtea ezoensis, and Thyasira oliveri n. sp. were recovered, but small bathymodioline mussels have not been found. This confirms that the small deep-sea mussels did not appear in the wood-fall communities at least by the earliest Thanetian.

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An ostracode fauna is described from lacustrine sediments of the Hettangian, Lower Jurassic, Whitmore Point Member of the Moenave Formation. The Moenave is well known for its rich, Late Triassic?–Early Jurassic fossil record, which includes fossil fishes, stromatolites, ostracodes, spinicaudatans, and a diverse ichnofauna of invertebrates and vertebrates. Four ostracode species, all belonging to the suborder Darwinulocopina, were recovered from these sediments: Suchonellina globosa, S. stricta, Whipplella? sp. 1, and W.? sp. 2. The diversity and composition of the Whitmore Point Member ostracode fauna agree with previous interpretations about Lake Dixie and nearby paleoenvironments as shallow lakes inhabited by darwinulocopine species that survived the effects of the Central Atlantic Magmatic Province and the subsequent end-Triassic extinction and quickly recolonized these areas, thanks to asexual reproduction by parthenogenesis. The Lake Dixie region, in its geographical isolation, could represent the last episode of darwinulocopine dominance in nonmarine environments before the Late Jurassic diversification of the cypridocopine/cytherocopine modern ostracodes.

The present work presents a detailed taxonomic study on Ostracoda from the Quiricó Formation, Areado Group, São Francisco Basin, Brazil. The samples were collected from three outcrops in the Minas Gerais State: Tereza Farm (João Pinheiro Municipality), and from the banks of the São José and Quiricó creeks (Presidente Olegário Municipality). Sixteen ostracode species were recovered: Harbinia alta, Harbinia aff. H. angulata, Harbinia aff. H. crepata, Harbinia aff. H. salitrensis, Harbinia symmetrica, Brasacypris fulfaroi, Brasacypris ovum, Cypridea conjugata, Cypridea hystrix, Cypridea infima, Cypridea jequiensis, Neuquenocypris (Protoneuquenocypris) antiqua, Penthesilenula martinsi, Penthesilenula pintoi new species, Alicenula longiformis new species, and Timiriasevia sanfranciscanensis new species. With the recovery of well-preserved specimens, it was possible to observe new characteristics in Brasacypris ovum, Cypridea conjugata, C. hystrix, and C. infima, and propose emendments to them. Additionally, three new species are described: Penthesilenula pintoi n. sp., Alicenula longiformis, n. sp., and Timiriasevia sanfranciscanensis n. sp. To date, the genus Timiriasevia had not been recorded in strata from Brazil. Also, Darwinula martinsi is reassigned to the genus Penthesilenula. Several species herein recorded are also found in other Brazilian continental basins, as well as in African and Argentinian basins, contributing to the knowledge of Brazilian Cretaceous continental deposits.

The Batocrinidae are characteristic faunal elements in Lower Mississippian shallow-marine settings in North America. Recent delineation of objectively defined genera allows a reexamination of batocrinid species and their distribution in the Fort Payne Formation (early Viséan, late Osagean), a well-studied array of carbonate and siliciclastic facies. The Fort Payne batocrinid fauna has 14 species assigned to six genera, plus hybrid specimens. Magnuscrinus spinosus (Miller and Gurley, 1895a) is reassigned to its original placement in Eretmocrinus. Hybrid specimens (Ausich and Meyer, 1994) are regarded as Eretmocrinus magnificus×Eretmocrinus spinosus. Macrocrinus casualis is the dominant species of Macrocrinus in the Fort Payne, and M. mundulus and M. strotobasilaris are recognized in the Fort Payne Formation for the first time. Magnuscrinus cumberlandensis n. sp. is named, 13 species are designated as junior synonyms, the name for the hybrid specimens is changed to Eretmocrinus magnificus×Eretmocrinus spinosus, and the previous occurrences of two species in the Fort Payne are rejected. The Eastern Interior Seaway was a mixed carbonate-siliciclastic setting with both shallow- and deep-water epicontinental sea facies ranging from relatively shallow autochthonous green shales to deep-water turbidite facies. Dizygocrinus was restricted to shallow-water carbonate and siliciclastic facies, Eutrochocrinus was restricted to shallow-water carbonate facies, and Magnuscrinus was restricted to deep-water facies. Species distributions varied from Abatocrinus steropes, Alloprosallocrinus conicus, Macrocrinus mundulus, and Uperocrinus nashvillae, which occurred throughout the Eastern Interior Seaway, to species that were restricted to a single facies. Eretmocrinus magnificus, Alloprosallocrinus conicus, and Uperocrinus robustus were the dominant batocrinids in the Fort Payne Formation.

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Complete body fossils of salamanders are relatively rare, but provide critical information on the evolutionary roots of extant urodele clades. We describe new specimens of the fossil salamandrids Taricha oligocenica Van Frank, 1955, and Taricha lindoei Naylor, 1979, from the Oligocene Mehama and John Day formations of Oregon that illustrate aspects of skeletal morphology previously unseen in these taxa, and contribute to our understanding of population-level variation. Morphological analysis of these specimens supports the classification of T. oligocenica and T. lindoei as two different species, distinct from extant Taricha. Parsimony-based, heuristic analysis of phylogeny using 108 morphological characters for 40 taxa yields different results from a phylogenetic analysis that excludes four taxa known only via vertebrae. Our smaller analysis generally agrees with molecular phylogenies of the family Salamandridae, but with poorer resolution for molgin newts, especially between Taricha and Notophthalmus. The analysis including all taxa produced polytomies mostly related to complications from several fossil taxa. The presence or absence of dorsally expanded, sculptured neural spine tables on trunk vertebrae, an important character in past descriptions of fossil salamandrids, appears to be either homoplastic within the Salamandridae, or requires an expansion of characters or character states. Taricha oligocenica and T. lindoei are separate species of an at least 33 million-year-old clade, but their relationships with each other and extant North American salamandrids remain unclear with current levels of morphological data. Salamandrid research requires additional morphological data, particularly for the vertebrae and ribs, to better resolve salamandrid evolutionary history through morphological characters.

The Late Triassic rhynchocephalian Clevosaurus latidens Fraser, 1993 is known from the fissure deposits of Cromhall Quarry, England. Many studies have questioned its referral to the genus Clevosaurus Swinton, 1939 and some phylogenetic analyses suggest a close relationship with herbivorous rhynchocephalians. We re-examine the type specimens and referred material of C. latidens to elucidate its taxonomic identity. Additionally, we provide new phylogenetic analyses of the Rhynchocephalia using both parsimony and Bayesian approaches. Our taxonomic review and both phylogenetic analyses reveal that C. latidens is not referable to Clevosaurus, but represents a new genus. We reassess C. latidens and provide an amended diagnosis for Fraserosphenodon new genus. Both parsimony and Bayesian analyses recover similar topologies and we propose formal names for two higher clades within Rhynchocephalia: Eusphenodontia new infraorder and Neosphenodontia new clade.

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Misidentified fossils are common in paleontology, but Platylithophycus has undergone a particularly problematic series of descriptions. The holotype of P. cretaceus comes from the Upper Cretaceous Niobrara Chalk of Kansas, and was first described as a calcareous green alga, based on the surface texture of the specimen. Later, Platylithophycus was re-identified as a sepiid cephalopod, based partly on a comparison of microstructure between P. cretaceus and the pen of modern squids. Platylithophycus then became part of the University of Nebraska teaching collection, where, according to paleontological legend, an undergraduate student suggested that the fossil’s tessellated surface looked a lot like shark cartilage. However, that interpretation has not been formally proposed until now. This work re-describes the holotype of Platylithophycus cretaceus as part of the branchial endoskeleton of an elasmobranch, based on both gross morphology and ultrastructure, including recognizable tessellated cartilage with intertesseral pores and joints.