How will freshwater lakes in the Arctic respond to climate change, especially if polar amplification results in even greater warming at these northern latitudes? Deep time analogs offer opportunities to understand the potential effects of future climate warming on arctic environments. A core from the Giraffe Pipe fossil locality located in the Northwest Territories of Canada offers a window into the life of a thriving Arctic freshwater ecosystem in the Eocene during greenhouse conditions. The remains of an extensive deposit of microfossils, including photosynthetic protists (chrysophytes, diatoms, and green algae), heterotrophic protists (euglyphids, heliozoans, paraphysomonads, and rotosphaerids), and sponges, were used to reconstruct the history of the ancient waterbody. Concentrations and diversity of chrysophyte taxa were extensive throughout the core, accounting for >70% of the microfossil remains. The ratio of chrysophyte cysts to diatom valves, with a mean value near 14 throughout the core, further emphasized the dominance of the chrysophytes, and given the high diversity of taxa, the locality represents a “paleo-hotspot” for this eukaryote lineage. Based on the totality of fossil evidence, the waterbody within the Giraffe Pipe crater represented a series of relatively shallow aquatic habitats, with changing physical and chemical conditions, and varying water depths. Five major zones were identified, each found to be stable for an extended period of time, but with distinct transitions between successive zones signaling significant shifts in environmental conditions. The study provides valuable insight on how Arctic freshwater ecosystems responded to past warm climates, and to the organisms that could potentially thrive in these environments under future warming scenarios.

The families Erinaceidae and Dimylidae are represented in the late Miocene localities of Slovakia (Borský Svätý Jur, Krásno, Pezinok, Šalgovce, Studienka, and Triblavina) by at least six hedgehog species—‘Schizogalerix’ voesendorfensis (Rabeder, 1973); Schizogalerix cf. S. moedlingensis (Rabeder, 1973); Lantanotherium sanmigueli Villalta and Crusafont, 1944; Atelerix cf. A. depereti Mein and Ginsburg, 2002; Atelerix aff. A. depereti, cf. Postpalerinaceus sp. indet., and Erinaceinae gen. indet. sp. indet.—and two dimylid species—Plesiodimylus chantrei Gaillard, 1897; and Metacordylodon aff. M. schlosseri (Andreae, 1904). Material of L. sanmigueli from the western Carpathians was investigated, revealing broad variability in all samples. Additionally, the deciduous premolars of Lantanotherium Filhol, 1888 are described here for the first time. Erinaceid species are frequent in the Vallesian but their abundance strongly declined afterward. As an exception, Schizogalerix Engesser, 1980 re-entered the Danube and Vienna basins during MN11, likely from eastern Europe. Members of Erinaceinae display low diversity during the late Miocene of central Europe, which tends to support a pan-European diversity phenomenon. The humidity-dependent Dimylidae spp. were abundant during the late Vallesian. Rare finds of Plesiodimylus Gaillard, 1897 confirm the survival of this family into the early MN11 in the Pannonian region.

The atrypide brachiopod Qilianotryma Xu in Jin et al., 1979 is an early member of the subfamily Spirigerininae initially described from the Katian (Upper Ordovician) Koumenzi Formation of the Qilian Mountains, Qaidam terrane, Northwest China. Qilianotryma suspectum (Popov in Nikiforova et al., 1982) is described for the first time from the Upper Ordovician of South China paleoplate. Serial sectioning in this study revealed the typical spiralia and other internal structures of early atrypides. The rephotographing of type material and discriminant analysis support that Qilianotryma and broadly similar Euroatrypa can be differentiated in terms of external morphology. The distribution of Qilianotryma across the South China paleoplate, Qaidam terrane, and a few Kazakh terranes (i.e., Chu-Ili, Boshchekul, and Chingiz-Tarbagatai) supports a low-latitude faunal province separate from that of Laurentia and Baltica during the Katian, but further work describing and reviewing additional fossil material from these plates and terranes may improve our understanding of the position of these plates and the role that paleogeography played in increasing biodiversity during the Ordovician Radiation.

Numerous species of “oliviform” gastropods have been recognized in the Paleogene of the U.S. Gulf Coastal Plain, many of which have previously been allied to the “Bullia group” in the family Nassariidae, and placed in a variety of poorly defined genera. We review these species, revise their generic and familial placement, and present a phylogenetic analysis. Of 19 species considered valid, all are assigned to Olivoidea, six to Olividae—one to Oliva, five to Agaronia—and the rest to Ancillariidae. The highly variable species Ancillaria altile Conrad is referred in the genus Ancillopsis and appears to have evolved anagenetically over an interval of perhaps 20 million years. Ancillaria tenera Conrad and Ancillaria scamba Conrad are placed in the new genus Palmoliva. Monoptygma Lea is demonstrated to belong to Ancillariidae, and to contain only a single species. Specimens assigned to Lisbonia expansa Palmer are split into adults assigned to Ancillopsis altilis and juveniles (together with several other species) in the long-lived species Anbullina elliptica (Whitfield). Coastal Plain ancillariids may have evolved from one or more species of the Cretaceous–Paleocene genus Eoancilla. We agree with previous authors who have suggested that the late Eocene species Oliva mississippiensis Conrad is the earliest known representative of this genus and the subfamily Oliviinae, perhaps derived from a species of Agaronia. The oldest Agaronia is lower Eocene (Ypresian).

UUID: http://zoobank.org/b7d9f79b-c68b-4385-aba3-bb07c6d6dc87

Middle Eocene deep-sea sediment sequences cored at Ocean Drilling Program Site 1260 (Leg 207; equatorial Atlantic Ocean) yielded diverse and abundant radiolarian faunas that are conducive to biostratigraphic and palaeoceanographic research, as well as to the study of radiolarian diversity dynamics during this epoch of significant climate changes. However, many species present in these sediments still have not been formally described and are therefore neglected in most biodiversity surveys. In an effort to improve the taxonomic resolution of middle Eocene radiolarians, 15 new species of nassellarians are described and illustrated. The species are: Cymaetron? dilatatus n. sp., Eucyrtidium levisaltatrix n. sp. (Eucyrtidiidae), Siphocampe pollen n. sp., Spirocyrtis? renaudiei n. sp. (Artostrobiidae), Pterocyrtidium eep n. sp. (Rhopalosyringiidae), Petalospyris cometa n. sp., Petalospyris castanea n. sp. (Cephalospyrididae), Velicucullus armatus n. sp. (Theophormididae), Lychnocanium nimrodi n. sp. (Lithochytrididae), Aphetocyrtis zamenhofi n. sp., Aphetocyrtis? columboi n. sp., Aphetocyrtis? spheniscus n. sp. (Lophocyrtiidae), Albatrossidium regis n. sp., Albatrossidium annikasanfilippoae n. sp., and Phormocyrtis lazari n. sp. (Pterocorythidae). Stratigraphic range data are provided for each new species, as well as the orbitally tuned ages for their first and last occurrences. In addition to these new species, we also illustrate and document the stratigraphic distribution of four species described in early radiolarian studies and rarely reported since.

UUID: http://zoobank.org/b5993e6b-659b-4220-80c2-c6ddccc13793

Two specimens of Metaconularia manni (Roy, 1935) from the lower Middle Silurian Scotch Grove Formation (eastern Iowa) exhibit well-defined, relict soft parts replicated in silica. One of these specimens bears phosphatic periderm, whereas the other specimen is a mold. Present within the erect, undistorted apical region of the specimen preserving periderm, on opposite sides of the peridermal cavity, are two small, elongate masses of silica located near the midlines of two of the four faces. Present in the central portion of the other specimen, at a somewhat greater distance from the apex, are five pairs of hollow, elongate, keeled pouch-like bodies (hereafter pouches), the long axes of which converge on the center of the fossil. Each pair of pouches is associated with a short, narrow, gently curved or broadly U-shaped tube, also composed of silica. Additionally, two of the pouch/tube combinations are associated with a pair of rectilinear furrows that correspond to the paired internal carinae that straddled the conulariid's facial midlines. We interpret the paired pouches and short tubes in the moldic specimen as relic conulariid soft parts homologous, respectively, to the interradial gonads and retractor muscles of extant, stauromedusan and polypoid scyphozoan cnidarians. Unlike most conulariids, which exhibit four faces, this individual had five faces, an aberrant morphology known in one other conulariid. The two small masses in the other specimen are more difficult to interpret, but they, too, could be relic gonads or longitudinal muscles. These interpretations suggest that, as in certain extant scyphozoans, at least one conulariid lost the free-living, sexual medusoid life phase.

The Jurassic rocks of Gebel Maghara, northern Sinai, Egypt, contain a well-preserved and highly diverse macrobenthic fauna, dominated by bivalves. This fauna, particularly bivalves and gastropods, have received little attention in the last 100 years. In an attempt to provide a sound database on the marine bivalve diversity of Egypt during the Jurassic period, a first faunal group, the protobranch bivalves, is reviewed in detail. Sixteen taxa (three of them new), belonging to two orders, five families, and nine genera are systematically described and compared to closely related Jurassic taxa from various locations, particularly in Europe and India. New species are Nuculoma douvillei n. sp., N. sinaiensis n. sp., and Palaeoneilo aegyptiaca n. sp. In addition, Palaeonucula cuneiformis (J. de C. Sowerby), P. muensteri (Goldfuss), Dacryomya diana (d'Orbigny), D. lacryma (J. de. C. Sowerby), and Praesaccella juriana Cox are identified from Jurassic strata of Egypt for the first time. The younger records of the genus Palaeoneilo have not been accepted by some researchers, since almost all exhibit only limited features. The genus occurs with certainty in the Middle Jurassic (Bajocian‒Bathonian) rocks of Egypt, based on well-preserved external and internal characters. Similarly, Dacryomya and Ryderia from Bathonian‒Kimmeridgian rocks of Egypt are younger than previously recorded from other parts of the world. The identified genera have wide geographic ranges and have been reported from different faunal provinces, which suggests that latitudinal climate differences did not influence their distribution pattern to a great extent.

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Neogondolella constricta (Mosher and Clark, 1965) from the Prida Formation at Fossil Hill in central Nevada was the first conodont described from Middle Triassic strata in North America. The species has since been widely reported from elsewhere despite uncertainties about its taxonomic scope and that of similar related taxa. Poor definition of these taxa has spawned a diverse nomenclature and inhibited use of the group in biozonation. Starting with a growth series of topotype N. constricta, we reassess allied contemporaneous taxa from North America. In Nevada, 11 conodont taxa are identified: N. constricta, N. aldae Kozur, Krainer, and Mostler, 1994b, N. cornuta Budurov and Stefanov, 1972, N. ex gr. mesotriassica (Kozur and Mostler, 1982), N. postcornuta (Kovács, 1994), N. posterolonga Kozur, Krainer, and Mostler, 1994b, N. quasiconstricta n. sp., N. quasicornuta n. sp., and three subspecies of N. excentrica Budurov and Stefanov, 1972. Successive associations of taxa display symmetry transition in posterior platform configuration. Subdivision of the upper Anisian–lower Ladinian is provided by dominant N. constricta plus relatively uncommon N. quasiconstricta n. sp. and N. excentrica primitiva n. subsp. in the Rotelliformis ammonoid zone. This is followed in the Meeki through the Subasperum zones by dominant N. cornuta, associated N. posterolonga, plus relatively uncommon N. quasicornuta n. sp., and a variety of asymmetric elements: the Meeki Zone includes N. aff. N. cornuta; the Occidentalis Zone adds N. e. excentrica; and finally, N. e. sigmoidalis n. subsp. appears in the Subasperum Zone. In British Columbia, the three subspecies of N. excentrica are recognized in, respectively, the Deleeni, Chischa, and Matutinum (and younger) ammonoid zones.

UUID: http://zoobank.org/7d58c8c8-cd68-498f-bb84-5d43de47f779

The Early Pennsylvanian Nagaiwa Formation contains fossils such as corals, fusulinids, and ostracodes, and its age and depositional environments have been determined by fusulinids and sedimentology. In this study, I describe the ostracode assemblages from the Nagaiwa Formation. Moreover, I provide a reconstruction of the paleogeography of northeastern Japan during the Early Pennsylvanian by comparing this ostracode assemblage with assemblages from other regions during the same period. Thirty ostracode species, including 12 genera, have been identified, most of which are endemic species and 10 of which are new: Jordanites michinokuensis n. sp., Thuringobolbina ikeyai n. sp., Aechmina iwatensis n. sp., Pseudobythocypris asiatica n. sp., P. zipangu n. sp., P. siveteri n. sp., Platyrhomboides tohokuensis n. sp., P. japonica n. sp., Healdia ofunatensis n. sp., and H. rikutyuensis n. sp. Two of these species are also found in central Japan. The ostracodes from the Nagaiwa Formation are unique when compared with any other similarly aged assemblages.

UUID: http://zoobank.org/c43f0787-4bb6-45d1-9c12-54a747c0b040

Tropidoleptus is a brachiopod genus with a very peculiar morphology that existed throughout the Devonian as a cosmopolitan taxon. Although there have been reports of the presence of this genus in the Paraná Basin since the nineteenth century, its actual occurrence has been the subject of much debate. The objective of this paper was to clarify this situation. For this purpose, dozens of specimens from Monjolo dos Padres and Juscimeira outcrops (São Domingos Formation, possibly Givetian) in the Brazilian state of Mato Grosso were analyzed. The samples studied here exhibit the typical characteristics of Tropidoleptus, confirming that this genus also occurred in the Paraná Basin. It is possible that Tropidoleptus entered the Paraná Basin during the Eifelian/Givetian from the Amazonas and/or Parnaíba basins (Brazil), during a period of warm-water transgression. When Tropidoleptus is found in situ, it can serve as an indicator of a shallower water environment (shoreface to shallower portions of transitional offshore). In the Paraná Basin, its presence can indicate rocks no older than the Eifelian–Givetian transition.

A diverse and well-preserved radiolarian assemblage from the Malongulli Formation, New South Wales, Australia, contains 13 species representing 10 genera and six families. One new genus, Wiradjuri, is introduced to accommodate pre-Devonian single-shelled entactiniid taxa, and one new species, Secuicollacta malongulliensis, is recorded together with some previously described forms. The microstructures of the “rotasphaerid structure/primary unit” and the “ectopic spicule” are investigated to validate their roles as fundamental units in the Secuicollactidae, together with comprehensive documentation of the previously enigmatic Pseudorotasphaera internal skeleton.

The results of this investigation suggest that, among all radiolarian genera that survived the Late Ordovician Mass Extinction event (LOME) and transitioned into the Silurian, Secuicollacta, Haplotaeniatum, and Palaeoephippium maintained stable body plans during the transition and were more successfully established. The selective advantages these lineages had during the LOME were most likely spontaneous outcomes of the mode of structural development involving sequential skeletogenesis and a tendency to evolve toward simpler body plans.

UUID: http://zoobank.org/264c026f-35af-4025-a4f7-de8f9a91f8b9

The morphology of Zygospira, an early atrypide brachiopod, was analyzed using a multivariate approach. Principal component analysis and discriminant analysis clearly differentiated species as they are currently defined primarily based on differences in shell size and ornamentation but not in terms of overall shell shape. The older Zygospira modesta was able to persist into the late Katian (Richmondian) while smaller early species in other brachiopod lineages mostly went extinct. This may have been possible through niche partitioning because the smaller shells have been found attached to other filter feeders and no larger species have been found in these associations so far. This could represent a rare example of sympatric speciation preserved in the fossil record. In the future, detailed study of the spiralia and their associated structures may provide clues as to the ultimate evolutionary affinities of this group in relation to the other atrypide brachiopods evolving at this time.

An unusual worm, previously interpreted as the earliest leech, is described from the early Silurian (Llandovery, Telychian) Brandon Bridge Formation Lagerstätte (Waukesha Biota) of Wisconsin (~437 Ma). Lacking preserved internal organs, it is up to ~16 cm long, 8.2 mm wide, with ~250 annulations and a circular structure at one end, interpreted here as the broken end of a molt. It is therefore referred to Cycloneuralia incertae sedis.

Spongiostroma Gürich, 1906 from the Mississippian of Belgium was initially provisionally placed in Foraminifera and subsequently compared with hydrozoans and microbial carbonates. For nearly 100 years, the term spongiostromate has been widely applied to clotted microbial fabrics in stromatolites and oncolites. Examination of the type material shows that S. mæandrinum Gürich, 1906, the type species of Spongiostroma, consists of numerous juxtaposed millimetric pillow-like masses permeated by thin anastomose sparry microscopic fibers (vermiform fabric) in fine-grained groundmass, locally traversed by millimetric rounded to elongate partly sediment-filled openings. Here we interpret S. mæandrinum to be a lobate sponge composed of mammiform papillae formed by calcified spongin network and traversed by canals and spongocoel. These are typical features of calcified remains of keratosan demosponges. We redescribe and revise S. mæandrinum and interpret it as a keratosan demosponge with papilliform morphology. This upholds Gürich's (1906) initial opinion that Spongiostroma could be a sponge and supports suggestions that keratosan vermiform fabric has long been confused with microbial carbonate. Since S. mæandrinum is not a stromatolite, it is inappropriate to use the term spongiostromate to describe microbial carbonate microfabric.

Two species of Teiichispira Yochelson and Jones reported from the Early/Middle Ordovician marine deposits of the San Juan Formation in the Argentine Precordillera are described. The new species Teiichispira teresae n. sp. is a component of the Early/Middle Ordovician marine gastropod assemblage in the studied region; Teiichispira argentina (Kayser), previously known from the San Juan Formation, is described with a complete teleoconch and associated operculum. The opercula of both Teiichispira species are complete and preserved in life position associated with the shell of T. argentina. The unguiculate morphology of the operculum is here interpreted as a mechanism for increasing the shell weight and ensuring anchoring to the substrate in a more or less fixed mode of life for Teiichispira, and as protection. The new occurrence of Teiichispira provides new taxonomic data on early Paleozoic marine gastropods in Argentina and testifies to a wide paleobiogeographical distribution for the genus, restricted to tropical and subtropical regions during the Early/Middle Ordovician.

UUID: http://zoobank.org/8ee48319-b17a-4d15-a7d4-99cc9bb1dc42

Solitary rugose corals assigned to Streptelasma rutkae n. sp. and an annulated orthoconic cephalopod identified as Gorbyoceras sp. occur in nearshore shallow-marine sandstone of the Whirlpool Formation in Hamilton, southern Ontario. They are the first macrofossils contributing to a modern understanding of the age and correlation of this stratigraphic unit. Streptelasma rutkae most closely resembles S. subregulare (Savage, 1913), which occurs widely in the Edgewood Province of the east-central United States, in strata considered latest Ordovician (Hirnantian). Gorbyoceras ranges into the latest Katian (latest Richmondian) in the Cincinnati Arch region. Thus, the occurrences of S. rutkae and Gorbyoceras sp. support other biostratigraphic and chemostratigraphic data suggesting that the Whirlpool Formation is latest Ordovician, rather than earliest Silurian as traditionally thought. They also indicate paleogeographic connections between the area of Whirlpool deposition in Ontario and the Edgewood Province and Cincinnati Arch region in the east-central United States

UUID: http://zoobank.org/d1ded814-204d-4070-a469-52d3b6e259c7

Patagorbitestella new genus is here proposed to include two extant and one fossil species: P. ponderi (Linse, 2002) new combination, P. patagonica (Simone and Zelaya, 2004) new combination, and P. leonensis new species, the last described from the Punta Entrada Member of Monte León Formation (50°21′25.4”S, 68°53′05.9″W, Aquitanian to lower Burdigalian, lower Miocene). A protoconch sculptured with distinctive microscopic spiral threads serves as a per se diagnostic shell character for the new genus. Patagorbitestella n. gen. constitutes a distinctive lineage of orbitestellid gastropods inhabiting exclusively the Magellanic Region at least since the early Miocene. This is the first fossil record of Orbitestellidae in South America.

UUID: http://zoobank.org/e48a4b73-1c0a-4bf7-aceb-8a180ef7e039