The Brechin Lagerstätte (Katian, Ordovician) from the Lake Simcoe region of Ontario, Canada contains a diverse array of echinoderms. Here, we describe seven disparid and two hybocrinid crinoids (subclass Pentacrinoidea, infraclass Inadunata), including a new disparid species belonging to the Anomalocrinidae (order Homocrinida). In total, the disparids include Anomalocrinus astrictus n. sp.; Cremacrinus guttenbergensis Kolata, 1975; C. inaequalis Billings, 1859; Daedalocrinus bellevillensis Billings, 1883; Eustenocrinus springeri Ulrich, 1925; Iocrinus trentonensis Walcott, 1883; and Isotomocrinus tenuis Billings, 1857b. The hybocrinids include Hybocrinus tumidus Billings, 1857a and Hybocystites problematicus Wetherby, 1880. Previously known from only the holotype, three additional specimens of E. springeri expand our understanding of this unusual crinoid. Nomenclatural acts include: (1) the recommended designation of D. kirki Ulrich, 1925 as a junior synonym of D. bellevillensis is followed; (2) Hybocrinus pristinus Billings, 1858 is designated as a junior synonym of H. tumidus, and previous decisions are followed to retain Hybocystites eldonensis (Parks, 1908) as a junior synonym of H. problematicus; (3) although probably assignable to Anomalocrinus Meek and Worthen, 1865, the aberrant crinoid Glaucocrinus falconeri Parks and Alcock, 1912, and its genus Glaucocrinus Parks and Alcock, 1912, are designated as nomena dubia; (4) Iocrinus similis (Billings, 1857) is also designated as a nomen dubium; and (5) Iocrinus subcrassus torontoensis Fritz, 1925 is designated a junior synonym of I. subcrassus Meek and Worthen, 1865.

UUID: http://zoobank.org/90f8580b-ed7e-4405-97b2-73c9069de7f5

A new genus and species of the Elcanidae (Orthoptera, Elcanoidea), Cascadelcana virginiana n. gen. n. sp., is described based on a forewing specimen from the Upper Triassic (Norian) Cow Branch Formation in the Solite Quarry Lagerstätte near the North Carolina-Virginia boundary, USA. It is distinguished from other elcanid species by its RP+MA1 with six branches, M with two branches before stem MA1 fused with RP, and short CuA almost vertical against the posterior margin. This fossil represents the earliest definitive record of the family Elcanidae and the first orthopteran described from the Triassic of North America. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analyses show that the veins and a pterostigma-like structure on the wing of C. virginiana n. gen. n. sp. are preserved as carbonaceous compressions. The presence of a pterostigma-like structure in elcanids indicates that they may have evolved a particular flight mechanism distinct from those of other orthopterans.

UUID: http://zoobank.org/49526c99-5da4-48e3-ba6e-7018b8f9b1ae

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.

Fossils can inform the study of modern ecosystems by showing how species interactions in ancient communities compare with those today and how extinction is selective not only with respect to species but also with respect to entire modes of life. We studied the life habits and pattern of occurrence of the barnacle Chesaconcavus chesapeakensis Zullo, 1992 on the shells of the gastropod Conradconfusus parilis (Conrad) and the bivalve Chesapecten santamaria (Tucker) from Chancellor’s Point in the Windmill Point Member of the St. Mary’s Formation (late Miocene, Tortonian) of Maryland. Using several criteria, we show that the barnacle occupied living hosts only. The 59% incidence of the barnacle on Conradconfusus parilis is high compared to known living associations between barnacles and gastropods. Although Conradconfusus parilis with and without barnacles do not differ in size, suggesting that the barnacle had little effect on this gastropod, there is some indication that Chesapecten santamaria with barnacles are somewhat smaller than those without and may therefore have been adversely affected by the presence of barnacles. On the basis of morphology and the low (15%) incidence of repaired scars, Conradconfusus parilis was a predator that did not use its shell lip to subdue prey. No ecological equivalents of Conradconfusus and Chesaconcavus have existed in the temperate northwestern Atlantic between Cape Cod and Cape Hatteras for the past three million years.

Actinocerid nautiloids from the Lhasai Formation in the Xainza region are studied systematically for the first time. The nautiloids are identified as Middle Ordovician in age based on stratigraphic correlations with those from North China, Sibumasu, North Australia (northern Gondwana), and North America (Laurentia). A cluster analysis shows strong affinities between the actinocerid nautiloids of the Lhasa Terrane and those of the Himalaya, North China, and Sibumasu terranes. Our results support Middle Ordovician paleogeographic reconstructions that place North China rather than South China much closer to Australia. Nine species assigned to six genera of Meitanoceratidae, Wutinoceratidae, Armenoceratidae, Ormoceratidae, and Discoactinoceratidae are described in detail: Pomphoceras nyalamense (Chen, 1975), Pomphoceras yaliense (Chen, 1975), Wutinoceras cf. W. foerstei (Endo, 1930), Mesowutinoceras giganteum Chen in Chen and Zou, 1984, Armenoceras tani (Grabau, 1922), Armenoceras teicherti Endo, 1932, Armenoceras xizangense new species, Deiroceras globosom Zou and Shen in Chen and Zou, 1984, and Discoactinoceras cf. D. multiplexum Kobayashi, 1927.

UUID: http://zoobank.org/ba851fea-e107-4754-a0f4-a70744e325ab

Evaniid wasps develop as solitary egg predators within the oothecae of cockroaches. Fossil evaniids are relatively common compared with most other parasitoid Hymenoptera, undoubtedly due to their searching for host cockroaches on tree trunks and thus an increased chance of being trapped in tree resin. The genus Parevania Kieffer, 1907 is widely distributed through the Old World and is also known from a small number of rather unremarkable fossil taxa. Here we add to this extinct fauna Parevania oculiseparata Jennings, Krogmann, and Austin new species from Baltic Eocene amber, a species that has highly modified compound eyes that are unique among the Hymenoptera, and possibly among insects as a whole. Parevania oculiseparata n. sp. possesses a prominent acute ridge extending across the entire dorso-ventral elongation of the eye surface. Modifications to the regular curved surface of the eyes are extremely rare among Hymenoptera and previously were only known from two species of Inostemma Haliday, 1833 (Platygastridae s. s.) and the three known species of Isomerala Shipp, 1894 (Eucharitidae). In describing this unusual fossil evaniid species, we also analyze the optical consequences of the eye surface discontinuity, and discuss different types of compound eye modifications that occur in other Hymenoptera and other insects.

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.

UUID: http://zoobank.org/125bd4ab-b172-43d9-80b9-57b75a805150

Fossil insects from the Triassic-Jurassic boundary of England could provide an important resource for investigating the severity of extinction events in the terrestrial realm of the uppermost Triassic. However, the fossil record is poorly understood for this period even though there are abundant historical collections. Many of these collections are still in need of taxonomic revision before they can be used to reconstruct past entomofaunas and make inferences about diversity change through time. This paper is part of a larger project to revise the taxonomy of insects across the Triassic-Jurassic boundary of England to better understand changes in insect diversity through the Triassic-Jurassic boundary and associated extinction period. Herein, the damsel-dragonfly family Liassophlebiidae Tillyard, 1925 is revised and an additional specimen from the Early Jurassic of Antarctica is included. Rossiphlebia new genus is erected for Liassophlebia jacksoni Zeuner, 1962; L. batheri Tillyard, 1925 is considered nomen dubium and another specimen originally attributed to L. batheri is identified as L. withersi Tillyard, 1925. Liassophlebia (?) clavigaster Tillyard, 1925 and L. (?) hopei (Brodie, 1845) are considered incertae sedis at the generic level. Liassophlebia gigantea Zeuner, 1962 is based on a fragmentary specimen but has several unique key characteristics. We redescribe it in Anglophlebia new genus and tentatively in Anglophlebiidae new family in Heterophlebioptera. Also discussed are L. magnifica Tillyard, 1925, L. withersi, and L. pseudomagnifica Whalley, 1985, which are redescribed with updated figures. Caraphlebia antarctica Carpenter, 1969 was originally described from the Early Jurassic of Antarctica as being closely related to Liassophlebia; it is herein confirmed in Selenothemistidae Handlirsch, 1939.

UUID: http://zoobank.org/8fe9a39c-1c3b-4bda-92a6-92c1a0fc95b8

The Cambrian Yanwangbian assemblage (Series 2, Stage 4) in South Shaanxi, China, is one of the Burgess Shale–type faunas as it represents the only relatively diverse Cambrian biota from the north margin of the Yangzte Platform, South China. The paleoscolecids (Cycloneuralia) illustrated herein are one of the major components of the fauna, although they appear to be much less abundant than skeletonized fossils, according to available collections. A new taxon, Shaanxiscolex xixiangensis new genus new species, is described based on the scleritome pattern: each annulus has two rows of alternating Hadimopanella-type plates positioned close to the borders, and a mosaic pattern of microplates occurs between the plates and within intersegmental furrows. The occurrence of the new taxon confirms a fairly diversified and widespread distribution of paleoscolecidan worms recognized in the early Cambrian of South China. Moreover, the ecology of paleoscolecids is reappraised based on burial position of the S. xixiangensis and gut contens of Cambrian taxa from South China, hinting that paleoscolecids (at least some taxa) were both deposit feeders and carnivores, as well as active bioturbators in the substrates of the Cambrian sea, which sheds new light on the ‘Cambrian Substrate Revolution.’

We describe a nearly complete, and thus extremely rare, feather star (Crinoidea, Comatulida) from Oligocene strata of North Otago/South Canterbury, New Zealand. A detailed analysis of this specimen, as well as newly recovered material and previously described fragmentary remains from nearby contemporaneous sedimentary units, in addition to relevant historical specimens, lead us to conclude that it cannot be placed in any currently established genus. A new genus, Rautangaroa, is proposed to accommodate it.

This intact specimen of Rautangaroa aotearoa (Eagle, 2007), provides rare data on the morphology of arms and cirri. It represents the first example of arm autotomy and regeneration in a fossil feather star and thus has bearing on the importance of predation to the evolutionary history of this group.

UUID: http://zoobank.org/c050dafd-93ba-4334-b11b-59209aabb588

Tarphycerids were diverse and abundant in Ordovician marine faunas. Beginning at the Late Ordovician extinction, the diversity of tarphycerids declined throughout the Silurian, until their extinction in the latest Silurian. Two genera survived the Late Ordovician extinction: Trocholites Conrad, 1838 (from which Ophioceras Barrande, 1865 probably diverged) and Discoceras Barrande, 1867 (= Graftonoceras Foerste, 1925). Discoceras graftonense (Meek and Worthen, 1870), so far known from the US, China, and Australia, is recorded from the Silurian of Bohemia and Gotland. Discoceras stridsbergi n. sp., D. lindstroemi n. sp., and D. sp. indet. from the Wenlock of Gotland and D. amissus (Barrande, 1865) from the Llandovery of Bohemia are all endemic species probably derived from D. graftonense. The distribution of D. graftonense and the origin of four species of Discoceras in the latest Sheinwoodian and early Homerian represent the last diversification and dispersion of the Tarphycerida. No tarphycerid species originated after the mid-Homerian extinction (Mulde and Lundgreni events). Silurian Discoceras retained the morphology and habitats of their Ordovician ancestors. The hatching time and autecology of juveniles has remained unclear. Evidence from the material studied suggests that juveniles were planktonic in habit, possessing a minute curved shell with few phragmocone chambers. Discoceras lindstroemi n. sp. is exceptional owing to its heteromorphic planispiral shell with coiling that changed during ontogeny, resulting in a changing aperture orientation and decreased maneuverability.

The bryozoan genus Aspidostoma Hincks, 1881 has been regarded as the only representative of the Aspidostomatidae Jullien, 1888 in Argentina to date. Its type species, Aspidostoma giganteum (Busk, 1854), is presently distributed in the Magellanic Region (Argentina and Chile) and has been recorded in Oligocene and Miocene fossil deposits of Santa Cruz and Chubut, respectively. New material from San Julián (late Oligocene), Monte León (early Miocene), Chenque (early to middle Miocene), and Puerto Madryn (late Miocene) formations suggests, however, that A. giganteum is not represented in the fossil record. Material from Puerto Madryn Formation previously regarded as A. giganteum is here recognized as Aspidostoma roveretoi new species. Aspidostoma ortmanni Canu, 1904 is revalidated for the species from the San Julián Formation. Aspidostoma armatum new species and Aspidostoma tehuelche new species are introduced for material from the Monte León and Chenque formations, respectively. Aspidostoma incrustans Canu, 1908, from the early Miocene, is redescribed. Melychocella Gordon and Taylor, 1999, which differs from Aspidostoma in having vicarious avicularia and lacking a median ridge and a quadrangular process proximal to the opesia-orifice, is so far represented by three Paleogene species from the Chatham Islands (Southwest Pacific). The material from Monte León allowed us to transfer Aspidostoma flammulum Canu, 1908 to Melychocella, resulting in the new combination Melychocella flammula (Canu, 1908). Melychocella biperforata new species is described from the lower Miocene Monte León and Chenque formations. The presence of Melychocella in the Neogene of Patagonia extends its geographic distribution and its temporal range.

UUID: http://zoobank.org/d84df2d8-cab2-4e74-82b8-7c67d938a58f

Betelgeusia brezinai new species (Radiasteridae, Paxillosida, Asteroidea) is described from diversely fossiliferous Upper Cretaceous methane seep deposits of South Dakota. Asteroids are rare at modern chemosynthetic settings, although a hydrothermal vent occurrence is known, and two possible fossil methane seep occurrences have been reported. The Radiasteridae is important to the interpretation of crown-group asteroid phylogeny. Two extant genera are assigned to the family: Radiaster is known from relatively few but geographically widely dispersed largely deeper-water settings, and Gephyreaster is uncommon over a range of depths in the North Pacific Ocean. Jurassic and Cretaceous radiasterids have been described from geographically widely separated localities. In morphological-based phylogenetic analyses, the Radiasteridae has been assigned to the order Paxillosida, and Gephyreaster is similarly placed in a molecular evaluation; Radiaster has not yet been treated in a molecular study. In molecular treatment, an approximately traditional Paxillosida is a sister taxon to a significant part of the traditional Valvatida. Comparative morphology of Mesozoic and extant asteroids enables a hypothesis for a stemward, Mesozoic paxillosidan.

A new ichnogenus and ichnospecies, Spirolites radwanskii, is a spiral boring recognized in large limestone clasts deposited in a Miocene cliff-foot ramp. It is characterized by a semi-circular or inverted Ω-shaped cross section, gradually increasing width, gradual entrenching in the rock from the narrower side, consistent coiling direction, steep margin from the wider side, two-order annuli, and occasional truncation of the narrower side by the wider part. It is interpreted as a boring of vermetid gastropods, similar to the recent Dendropoma. Spirolites co-occurs with the bivalve borings Gastrochaenolites, mostly G. torpedo, sponge borings Entobia, and the spionid polychaete boring Caulostrepsis, which are typical of the Entobia ichnofacies. Spirolites was produced in very shallow, clean and warm sea waters.

Disarticulated net-like plates of the lobopod Microdictyon had a near cosmopolitan distribution from the early to middle Cambrian but are yet to be documented from the North China Platform. Here we report isolated plates of Microdictyon from the lower Cambrian Xinji Formation (Stage 4, Series 2) of the North China Platform, extending the paleogeographic distribution of Microdictyon in the early Cambrian. The plates of Microdictyon from the Xinji Formation are similar to those of other species established on the basis of isolated plates but do bear some new characters, such as mushroom-shaped nodes with a single inclined platform-like apex and an upper surface that displays radial lines. However, the plates documented here are left under open nomenclature due to inadequate knowledge of intraspecific and ontogenetic variation and low specimen numbers. Through comparison of the node shapes of the isolated plates of different Microdictyon species, we consider that low mushroom-shaped nodes could be a primitive and conservative character of Microdictyon while tall mushroom-shaped nodes may be a derived character. Subtle differences in shape and number of node apices may also represent intraspecific or ontogenetic variation.

Sinothemis difficilis new genus new species, youngest and first accurate Chinese representative of the small family Selenothemistidae, is described and illustrated. It is closely related to the genus Turanothemis, known from the Karatau outcrop in Kazakhstan. The genus Caraphlebia, known from the Middle Jurassic of Antarctica, seems to strongly differ from the other representatives of this family and may belong to another family. The fossil was collected from the Upper Jurassic (157.3 ± 1.5 Ma; near Oxfordian/Kimmeridgian boundary) Guancaishan locality, Jianping County, Western Liaoning, NE China. It belongs to the late assemblage of the Yanliao biota, while the early assemblage is represented by the putatively close damsel-dragonfly Paraliassophlebia from the Jiulongshan Formation of northern Hebei Province.

UUID: http://zoobank.org/8b11b148-852e-4079-a9fb-1884bf4b6d94

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.

Spinicaudatans (‘clam shrimps’) are small branchiopod crustaceans enclosed in a chitinous bivalved carapace that is often the only preserved element in the fossil record. However, few studies have analyzed the preservation of these carapaces, which have been found in continental facies from the Devonian to the present. The aim of this study was to contribute to a better understanding of the chemical preservation of fossil spinicaudatan carapaces, and it focused on spinicaudatan carapaces of the Cañadón Asfalto Formation from the Jurassic of Argentina. Semiquantitative energy-dispersive X-ray spectrometry (EDS) analysis provided elemental composition data that were interpreted using principal component analysis (PCA). The results showed a complex chemical mode of preservation for spinicaudatan carapaces. In some parts, EDS spectra of the specimens exhibit peaks of calcium, phosphorous, aluminum, and fluorine, representing the retention of original carapace material with some diagenetic recrystallization. Certain zones of the carapace show low-intensity peaks of the elements mentioned, while silicon and oxygen peaks (from the rock matrix) become the dominant spectral signals. These modes of preservation modify the interpretations and observations of the ornamentation of the carapace, which are used as taxonomic features. Our results suggest that specific diagenetic processes play a fundamental role in the preservation of spinicaudatans.

New morphological features of the mobergellan Discinella micans (Billings, 1871) from the lower Cambrian (Stage 4) of Northeast Greenland and southern Labrador are described. The new features include: (1) the morphology of the larval shell, which is shown to be cap-shaped, subcircular, and with impressions of the internal muscle attachment scars; (2) a range of unusual shell deformations (changes in growth direction resulting in thickened shells, partial detachment of shell laminae and subsequent regrowth, internal projections of shell material increasing the depth of the shell by up to 150%, disturbances and irregular fusion of muscle scars). In addition, we provide new details about the variability in number and shape of the anteriormost internal muscle scars, which often fuse and may vary in number from one to three (resulting in nine to 11 scars in total). Together the new observations provide additional strength for the hypothesis that mobergellan shells represent opercula of an as yet unknown tubular organism.