Late Triassic coniferous species of silicified woods are described from the Tronquimalal Group, Llantenes Depocenter of the Neuquén Basin, southern Mendoza Province, Argentina. The new species Agathoxylon cozzoi and Agathoxylon lamaibandianusCrisafulli and Herbst, 2011 described in this study were found in proximal volcaniclastic facies deposited in alluvial fans and proximal braided river plains of the Chihuido Formation, which is the basal unit of the Group. The species A. lamaibandianus Crisafulli and Herbst, Protojuniperoxylon ischigualastense (Bonetti, 1966) Bodnar and Artabe, 2007, and the new species Cupressinoxylon llantenesense also described in this study were collected from the upper fluvio-deltaic plain and delta-plain deposits that prograded into a large, meromictic and wedge-shaped lake of the overlying Llantenes Formation. The Tronquimalal Group yields abundant and well-known Triassic plant remains of the Southern Gondwana “Dicroidium Flora,” although it also contains typical early Jurassic taxa displaying age affinities with other Argentinean “Florian Stage” communities of Late Triassic (Norian–?Rhaetian). The lignotaxa described from both units of the Tronquimalal Group may all together represent coniferous forests of the extratropical area of the Southwestern Province of Gondwana. Deciduous conifer forests associated with herbaceous and shrub communities dominated by ferns and smaller corystosperms, and other taxa including the Linguifolium leaves within the Llantenes Depocenter environments, were developed on the western margin of the continent under seasonal temperate-warm and humid to sub-humid climate with a marine influence from the west.

A new, previously undescribed Middle Ordovician (middle Darriwilian: Dw2) radiolarian assemblage has been recovered from the Table Cove Formation at Piccadilly Quarry, western Newfoundland. Constituents of the fauna described herein are both distinctive and exceptionally well preserved. Three-dimensional X-ray micro-computed tomography (µ-CT) is used to make a detailed examination of four key spumellarian specimens. This technology enables visualization of hitherto ambiguous details of the internal morphologies of key lower Paleozoic taxonomic groups, among which a lack of knowledge has impeded resolution of higher taxonomic rankings.

A small (1.2 m) columnar carbonate mound in shaley strata equivalent to the Hartselle Sandstone (lower Serpukhovian) near Woodville, northeastern Alabama, was built by a consortium of species unlike those of other Carboniferous mounds in the southeastern United States. The mound contains a new problematic microencruster, Aphralysia anfracta new species, along with encrusting bryozoans (FistuliporaM'Coy, 1849), nonskeletal microbes, and other microencrusters, including Aphralysia caprioraeMamet and Roux, 1975, in a carbonate mud matrix. Mound cavities are filled with three generations of carbonate and siliciclastic sediment. Other biotic constituents of the mound include oncoids, sponges (including PileospongiaRigby, Keyes, and Horowitz, 1979), gastropods, crinoids, a tabulate coral, and coenobionts, including coccoid calcimicrobes. The mound biota, especially the microencrusters, is dramatically different from those of other Serpukhovian mounds that have been described from Alabama (made by various consortia of rugose corals, fenestrate bryozoans, crinoids, sponges, and nonskeletal microbes). Indeed, the Woodville mound extends the range of the lower Carboniferous encruster AphralysiaGarwood, 1914 to North America.

Octapyrgites elongatus n. gen. n. sp., a relatively rare, tetraradial olivooid (Cnidaria, Medusozoa), is described from Bed 5 of the Yanjiahe Formation (Cambrian Stage 2) near Yichang, China. Although similar to Olivooides and Quadrapyrgites from the Fortunian Stage in consisting of a partially corrugated (longitudinal) periderm with a quadrate (transverse) apical portion and V-shaped apertural lobes, O. elongatus is substantially larger than other olivooids. The elongate apical region of O. elongatus is similar to four-sided Anaconularia anomala (Barrande, 1867), though with a flat tip that may have been an adaption for a sessile mode of life. As in other olivooids, embryonic development in O. elongatus may have been direct. Last, the paucity of olivooids and the absence of pentaradial cnidarians and carinachitids in Cambrian Stage 2 indicate a marked decline in the disparity of cnidarians near the Fortunian–Cambrian Age 2 boundary, when by contrast bilaterians underwent rapid diversification.

An example of parasitic drilling in a rhynchonelliform brachiopod is described from the Shiyanhe Formation (Katian, Upper Ordovician) of Henan, central China. The boring extends into the shell almost perpendicular to the surface. The shell has been serially sectioned, and the trace (including boring and bioclaustration) has been modeled in three dimensions. Healing of the shell evident in serial sections supports a long-term relationship between the brachiopod and borer that we interpret as parasitic. Platyceratid gastropods, found at the same locality as these brachiopods, are the most likely drilling organism. Previous reports of Paleozoic brachiopod parasitic traces can be classified into two main groups, constructive association and destructive association, depending on whether parasites damage brachiopod shells. The example in this study belongs to the second type as the brachiopod shell has been partly damaged by the borer.

The small, Lower Cretaceous, iron ore deposit at Zengővárkony (Mecsek Mountains, southern Hungary, Europe) contains new brachiopod taxa of kingenoid relationships. Dictyothyropsis vogli, Zittelina hofmanni, and Smirnovina ferraria are described as new species from late Valanginian to earliest Hauterivian strata. The new taxa strengthen the presence of Early Cretaceous biogeographical connections with the Western Carpathians and the Pieniny Klippen Belt of southern Poland. The newly described taxa have significantly larger dimensions than their closest relatives from the type localities, which is in line with previous research on brachiopods from this environment. These brachiopods lived in a nutrient-rich, unique environment related to iron-ore deposition linked to former hydrothermal activity on the seafloor that might have contributed to the large size of these brachiopods. Larger than normal rhynchonellide and terebratulidine brachiopods have previously been recorded from this locality.

The Veneridae are the most speciose modern family of bivalves, and one of the most morphologically conservative and homoplastic, making subfamily- and sometimes even genus-level classification difficult. The widespread Cretaceous genus LegumenConrad, 1858 is currently placed in the subfamily Tapetinae of the Veneridae, although it more closely resembles the Solenoida (razor clams, Pharidae and Solenidae) in general shell form. Here we provide high-resolution images of the Legumen hinge for the first time. We confirm from hinge morphology that Legumen belongs in Veneridae, but it should be referred to incertae subfamiliae, rather than retained in the Tapetinae, particularly in light of the incomplete and unstable understanding of venerid systematics. Legumen represents a unique hinge dentition and a shell form—and associated life habit—that is absent in the modern Veneridae despite their taxonomic diversity. Veneridae are hyperdiverse in the modern fauna, but strikingly ‘under-disparate,’ having lost forms while gaining species in the long recovery from the end-Cretaceous extinction.

The homalonotid trilobite BurmeisteriaSalter, 1865 is revised from material from the Lower Devonian of central western Argentina (the Talacasto Formation in the Precordillera Basin). In contrast to other closely related Devonian marine basins from South America (mainly Bolivia, Brazil and Uruguay), the only species recognized in Argentina include Burmeisteria herschelii (Murchison, 1839) and B. notica (Clarke, 1913). New observations on the structure of the carapace indicate that structures sometimes interpreted as granules with taxonomic meaning are, in fact, taphonomic characters that represent the fillings of pore canals exposed by decortication. The antero-ventral process of the rostral plate may be a locking device during enrollment, which allowed long-term defensive behavior with a minimum of muscular energy. Burmeisteria is an upper Silurian to Middle Devonian endemic representative of southwestern Gondwanan (Malvinokaffric) basins. In the Argentine Precordillera Basin, this genus is virtually restricted to a sandy, Pragian, stratigraphic interval capped by a marker bed first reported by Keidel in 1921.

Cicadomorpha guancaishanensis new species, of the extinct family Palaeontinidae, is described from the Upper Jurassic Tiaojishan Formation at Guancaishan, Jianping County, Western Liaoning, northeastern China. It represents the first record of Palaeontinidae from the Tiaojishan Formation and highlights the palaeodiversity of the Late Jurassic palaeontinids. CicadomorphaMartynov, 1926 previously included three species with extremely limited morphological differences from the Karabastau Formation of Kazakhstan, the Glushkovo Formation, and the Ukurei Formation of Chita, Transbaikalia, and Russia, indicating a correlated stratigraphic relationship. This discovery provides new evidence that closure of the Okhotsk Ocean began in the Middle Jurassic. Thus, there is no distinct geographical barrier between the southern and northern areas of Mongolia-Okhotsk Ocean in the Late Jurassic.

Three new Llandovery (early Silurian) crinoids from Estonia provide an improved understanding of the paleogeographic aspects of the crinoid diversification following the end-Ordovician extinctions. The new taxa are Euspirocrinus hintsae new species (Rhuddanian eucladid), Oepikicrinus perensae new genus new species (Aeronian camerate), and Rozhnovicrinus isakarae new genus new species (Aeronian eucladid). This brings the total of described Llandovery crinoids in Estonia to eight nominal species and a further three taxa in open nomenclature. The Rhuddanian radiation in Baltica mirrored that on Laurentia and Avalonia and was dominated by Ordovician clades that continued to diversify during the Silurian. Known Aeronian crinoids from Estonia continue these clades, whereas new clades diversified on Laurentia and Avalonia. However, by the Wenlock, a largely cosmopolitan fauna existed on Laurentia, Avalonia, and Baltica.

Schoenaster carterensis new species, is an asteroid-like ophiuroid (Echinodermata) from Upper Mississippian (Chesterian) shallow-water carbonates in the Ramey Creek Member of the Slade Formation in northeastern Kentucky. First described in the 1860s from Lower and Middle Mississippian rocks, SchoenasterMeek and Worthen, 1860 is not a well-known fossil genus, but the 39 specimens in this collection permitted further definition of the genus and extended its range by ca. 17 Ma into Late Mississippian (Chesterian) time. The number of specimens also permitted differentiation of growth stages based on average arm length and showed that arm length, disk perimeter, and disk area are interrelated in statistically significant ways. Although replaced by chert, the specimens are nearly intact due to rapid burial as rare constituents in habitat communities distributed among four once-contiguous habitats, including shoal, shoal margin, transitional, and basinal. Most of the ophiuroids were concentrated on firm grounds or hardgrounds in shoal and transitional environments, concentrations that probably reflect substratum stability and the ability to support the ophiuroid's generalist feeding strategy. Many fossil ophiuroid species are known from only a few specimens, severely limiting interpretations about their detailed taxonomy, individual variation, and ecology. In contrast, the greater number of specimens and extensive knowledge of geologic occurrence in this study permitted detailed interpretations regarding the taxonomic, intraspecific, and ecologic attributes of this species, which might be useful in the study of other fossil ophiuroids.

A new species of Hypolophites (Chondrichthyes, Myliobatiformes) is described from an assemblage of isolated pavement teeth recovered from the Lower Clayton Limestone Unit of the Midway Group (Paleocene) near Malvern, Arkansas. These teeth were collected from several localized lag deposits containing an abundance of chondrichthyan and osteichthyan teeth, invertebrate remains, and trace fossils indicative of a marginal-shallow marine depositional environment. To date, only four additional species of Hypolophites have been reported from Paleocene deposits that occur along the west coast of central-northern Africa and in central New Jersey, USA. The identification of Hypolophites beckeri n. sp. in southwestern Arkansas extends the distribution of this biostratigraphically significant genus ∼1,750 km westward into the Mississippi Embayment and Gulf Coastal Plain of the USA. The distribution of Hypolophites species during the Paleocene attests to the uniformity of shallow marine shelves between western Africa and the Atlantic and Gulf Coastal Plains of the USA, as well as myliobatiform diversification following the K/Pg mass extinction event.

Cardichelyon rogerwoodi is an enigmatic fossil turtle from the late Paleocene to early Eocene of North America. Previous analyses suggested affiliation with Testudinoidea, in particular the big-headed turtle Platysternon megacephalum, based on the presence of multiple musk-duct foramina and a large head. We here highlight previously undocumented characteristics for this turtle, notably the presence of short costiform processes, a rib-like axillary process, and a posterior plastral hinge. Phylogenetic analysis places Cardichelyon rogerwoodi within Testudinoidea, but the exclusion of testudinoids suggest an affiliation with Dermatemydidae. Using consilience with external data we favor placement within Kinosternoidea. Cardichelyon rogerwoodi is therefore an aberrant, hinged kinosternoid that developed in situ in North America during the Paleocene long before the arrival of testudinoids on this continent in the early Eocene.

Kazachostylops occidentalisNesov, 1987b, based on partial maxilla and dentary from the upper Paleocene Zhylga locality in South Kazakhstan, is redescribed. A new phylogenetic hypothesis of Arctostylopida is proposed based on phylogenetic analysis of 26 characters and 17 taxa. Kazachostylops is recovered as a sister taxon to the Arctostylopinae, the advanced clade of Asian and North American arctostylopids characterized by pseudohypocone on upper molars and reduced trigonid of lower molars, with the ectolophid being attached labial on the trigonid. Kazachostylops differs from more basal arctostylopids (Asiostylops, Allostylops, Bothriostylops, and Wanostylops) by higher-crowned molars, M1–3 metaconule absent, m1–3 entoconid connected with ectolophid by entolophid, and m2 wider than m1 and m3. Principal component analyses of the upper and lower dentition of arctostylopids show great distinctness of Kazachostylops from other members of the group. The arctostylopid taxa are reviewed, and the new genus Enantiostylops is erected for ‘Sinostylops’ progressusTang and Yan, 1976 from the lower Eocene of China, because of uniquely concave parastylar area on upper molars.

A long hiatus encompassing most of the Eocene (end of the Ypresian to the early Priabonian) breaks up the proboscidean evolutionary history, which is otherwise documented by a rich fossil record. Only two post-Ypresian localities from West Africa (Mali and Senegal) have yielded scarce Moeritherium-like dental remains. Here, we study one of these remains from Senegal and name a new genus and species, Saloumia gorodiskii. This taxon, confidently mid-Lutetian in age, evokes Moeritherium and elephantiforms with its wrinkled enamel, lack of centrocrista, and strong lingual cingulum. However, due to its pronounced bunodonty, which departs from the bunolophodonty of both Moeritherium and elephantiforms, we cannot exclude the possibility that Saloumia documents an early experiment in dental diversity among Paleocene–Eocene proboscideans, without direct relationships with later proboscideans.

A number of putative annelid worms have been described from Ordovician strata, and these records are included in large-scale compilations of paleontological data. If these fossils are worms, they may yield important phylogenetic information; conversely, if they are not worms, they should not be included in large-scale databases. In either case, restudy of the type material of these supposed annelids is useful. The type material (holotype and one paratype) of one of these putative annelids, Haileyia adhaerensRuedemann, 1934, from the Middle Ordovician Normanskill Shale of Idaho, USA, is re-described and re-illustrated. The original description stated that the species is segmented, with parapodia, papillae, and setae, and lived attached to graptolites. Upon re-examination, the setae could not be detected, and the segmentation, parapodia, and papillae are herein re-interpreted as taphonomic, rather than biological, features. The supposed attachment of Haileyia to graptolites is likely to represent fortuitous bedding-surface associations. There is no evidence that Haileyia adhaerens is an annelid, or even a recognizable fossil.