Procolophonidae, a clade of stem reptiles, are hypothesized to be some of the first highly specialized herbivores to evolve following the end-Permian mass extinction event. That hypothesis is largely based on qualitative observations of tooth shape, which are highly subjective and not generalizable. Quantitative studies of reptilian tooth shape have employed relatively sophisticated methods to capture tooth complexity, but these approaches often require expensive equipment and software and are time intensive. In this study, we built a predictive model based on extant lizards to quantitatively predict the diets of procolophonids using simple measures of tooth morphology. We use linear discriminant analysis (LDA) to predict dietary ecology from tooth dimensions and phylogenetic MANOVA to test for significant differences in tooth dimensions for different diet categories. We report two key findings: (1) procolophonids are largely predicted as herbivorous but occupy a different area of the LDA space from extant lizards, and (2) simple metrics return similar results as complex methods, but with less confidence. We hypothesize that Triassic flora posed different mechanical and processing challenges from modern plants, which contributed to the unique tooth morphologies of procolophonids and likely other Triassic taxa.

Cambrian faunas of the Grand Canyon are neither diverse nor abundant, and several historical collections seem to have mixed taxa from several biozones. As a result, fine-scale reinterpretation of Grand Canyon biostratigraphy and broader-scale correlation of the Tonto Group and its fossils have been hampered by the lack of definitive and refined biostratigraphic indicators. Here we report new fossil occurrences from the Tonto Group, including from units that previously lacked biomineralized fossils, such as the Frenchman Mountain Dolostone. When integrated with historic collections, our data indicate that the Tonto Group ranges from the upper Dyeran to lowermost Steptoean Laurentian stages (global upper Series 2, Stage 4 to basal Furongian Series, Paibian Stage). Trilobite assemblages span the upper Dyeran (Peachella iddingsi Biozone) to lower Marjuman (Bolaspidella Biozone) stages and are distributed from the uppermost Tapeats Sandstone to lowermost Frenchman Mountain Dolostone.

Based on lithologic and paleontological data, three disconformities occur within the Cambrian of the Grand Canyon: (1) between the Dyeran and Delamaran stages in the uppermost Tapeats to lowermost Bright Angel Formation, (2) within the Delamaran Stage within the Bright Angel Formation, and (3) between the Delamaran and Topazan stages, higher in the Bright Angel Formation.

Cambrian trilobites from the Tonto Group consist of seven olenelloid, 17 corynexochid, and 33 ptychoparioid species, as well as 10 taxa that are not identifiable at generic or higher levels. New species include Kootenia barensis and Albertella nebeli. Some taxa are new to the Grand Canyon region, although they are known from the Great Basin (Nevada, California), southern Arizona, Montana, and Canada. These taxa include olenellids: Mesonacis fremonti (Walcott), Olenellus gilberti Meek in White, Olenellus terminatus Palmer, and Olenellus cf. O. fowleri Palmer; corynexochids: Anoria? bessus (Walcott), Caspimexis cf. C. radiatus (Palmer in Palmer and Halley), Kootenia aff. K. granulospinosa Palmer, 1968, and Zacanthoides cf. Z. typicalis (Walcott); and ptychopariids: Amecephalus cf. Am. normale (Resser), Am. piochensis (Walcott), Am. scapegoatensis (Deiss), Crepicephalus? upis Walcott, Ehmania weedi Resser, Eldoradia cf. E. prospectensis (Walcott), Glyphaspis tetonensis Resser, Kochina vestita Resser, Mexicella cf. Me. robusta Sundberg and McCollum, Mexicella mexicana Lochman, Modocia sp. indet., Solenopleurella? quadrata Rasetti, Trachycheilus granulosus Sundberg, and Tr. whirlwindensis Sundberg. Type specimens of Solenopleurella erosa Resser was divided into two species: the pygidia are assigned to Kootenia erosa (Resser) new combination, and the much smaller cranidia are assigned to Spencella? sp. indet.

UUID: http://zoobank.org/f3034b33-00d1-4d00-a9d5-0a73f7a330d2

New discoveries prompt reinterpretations of one of the most enigmatic echinoderm classes, the Cyclocystoidea. Exceptionally well-preserved cyclocystoids have been discovered in the Upper Ordovician (Katian) Kirkfield and Verulam formations in the Lake Simcoe region of southern Ontario, Canada. Four different cyclocystoid taxa are present, including Cyclocystoides cf. C. scammaphoris, Nicholsodiscus cf. N. anticostiensis, Zygocycloides marstoni, and Brechincycloides stanhynei new genus new species. These specimens reveal that the central disk of cyclocystoids consists largely of perforate extraxial plates and that the ever-present sutural pores are epispires surrounded by annular plates that may or may not be in lateral contact with each other. The specimens of B. stanhynei n. gen. n. sp. are significant because they are the first cyclocystoid fossils to reveal that the hydropore/gonopore and periproct are positioned on the aboral side of the central disk. The suggestively complex marginal ring, previously of undetermined origin, represents articulated floor plates in a circular arrangement supporting a circumferential water vascular system. Furthermore, the marginal ring reveals growth zones that correspond to axes of pentaradial symmetry. In the new interpretation, cupules are tube foot basins, and channels through the marginal ossicles can be explained best in the context of the axial origin as floor plates accompanied by a cover plate system. Application of the Extraxial–Axial Theory (EAT) compels a revised understanding of key anatomies comparable with other early radial echinoderms. We document evidence for cyclocystoid orientation in life with epispires facing upward and the tube foot basins in the floor plates directed towards the substrate. The new family Brechincycloididae is proposed for all cyclocystoids whose apomorphy consists of a flat, attenuated shelf tapering away from the proximal side of each floor plate.

UUID: http://zoobank.org/605fdf27-b38b-4d41-824b-d10b139f90f5

Biostratigraphic characterization of the Upper Ordovician in the Cincinnati region is complicated by several issues including provincialism of conodonts and graptolites, their facies dependence, the lack of biostratigraphical resolution for conodonts, and the absence of graptolites from many sections. Our study of the MY-14-01 core from Maysville (Kentucky, USA), type area for the Maysvillian Regional Stage of the Cincinnatian Series, suggests that chitinozoan biostratigraphy has the potential to strengthen the existing biostratigraphic framework based on conodonts and graptolites. Our samples usually yielded abundant, well-preserved chitinozoans in diverse populations. Many of these taxa are present in biostratigraphic reference sections from other parts of the Laurentian paleocontinent (Quebec and Anticosti Island, Canada, and Nevada, USA) and Avalonia (England and Wales). Here we provide systematic descriptions of selected chitinozoan taxa, including those of 12 new species: Conochitina rudis, Tanuchitina hooksae, Belonechitina laciniata, Hercochitina andresenae, Hercochitina anningae, Hercochitina edingerae, Hercochitina krafftae, Hercochitina polygonia, Hercochitina tharpae, Clathrochitina mangle, Angochitina bascomae, and Nevadachitina soufianei. One new name combination is proposed: Belonechitina duplicitas (Martin, 1983). This study provides a robust starting point for further advancing the Katian chronostratigraphic framework of the U.S. midcontinent.

UUID: http://zoobank.org/dc3e7fb1-a9ad-4681-8fec-701857abec4e

The study of Ordovician ostracods from eastern North America has been neglected for more than 40 years, prompting the need for taxonomic updates. Newly acquired silicified materials from the Late Ordovician Crown Point Formation of Valcour Island, northeastern New York State, are here systematically described. Fifty-two species of 42 genera are identified, including three new species: Vogdesella longidorsa n. sp., Eokloedenella duodepressa n. sp. and Aviacypris valcourensis n. sp. The combination of high diversity and dominance of both beyrichiocopids and podocopids indicates that the Valcour fauna existed in a stable, shallow-water carbonate environment. Biostratigraphical evidence supports an early Sandbian age designation for the Crown Point Formation. Comparison of the Valcour fauna with others in Laurentia as well as from adjacent paleocontinents shows shared composition at the genus level, especially with Baltica, but high endemicity at the species level. This suggests a history of frequent faunal exchange with a fast speciation rate during the early Late Ordovician in the southern region of Laurentia.

UUID: http://zoobank.org/e12dc8ce-0b2a-4f9d-aca2-bf3e298d9635

A total of 12 ostracodes species belonging to 10 genera are reported for the first time from the lower Pliocene Takikawa Formation in Takikawa City, Hokkaido, northern Japan. The ostracode fauna of the formation includes both cryophilic and circumpolar species. Cryophilic species are Baffinicythere robusticostata Irizuki, 1996, Neomonoceratina tsurugasakensis (Tabuki, 1986), and Yezocythere hayashii Hanai and Ikeya, 1991, and circumpolar species are Palmenella limicola (Norman, 1867) and Semicytherura mainensis (Hazel and Valentine, 1969). The co-occurrence of cryophilic and circumpolar species suggests that the marine environment was strongly influenced by extremely cold water masses. The species diversity and equitability of the fossil ostracode assemblages indicate that the depositional topography was the inner area of a bay. One new genus and one new species, Woodeltia sorapuchiensis new genus new species, are described. This new genus occurred in a temperate environment in Japan, in the early Miocene. In the early Pliocene, Woodeltia adapted to cold environmental conditions in Hokkaido. We hypothesize that Woodeltia sorapuchiensis is an important species for Woodeltia, showing the group’s adaptation to cold environments and migration to the coast of North America.

UUID: http://zoobank.org/144937f5-1161-42a9-9cc1-5c652cdb88b3

Evidence for parasites in the fossil record is rare. As such, any examples present insight into parasitism in deep time. Trilobites have often been used for documenting parasites in the Paleozoic. Here we examine an Illaenus sp. pygidium from the Middle Ordovician of Estonia that displays thirteen small structures with domical to crater-like shapes. These morphologies are consistent with circular depressions on the pygidium inner surface. We propose that these structures formed while the trilobite was alive and record an infestation located within soft tissue. The trace maker seems to have influenced pygidial mineralization and caused a pathological reaction. The symbiont may have been capable of bioerosion, excavating these depressions by dissolving the trilobite’s mineral tissues; however, this scenario is less likely considering comparisons with syndromes and pathologies known in modern arthropods. The parasitic organism may have fed on the trilobite’s tissues or utilized nutrients within the trilobite’s body for growth. These observations are consistent with a parasitic organism.

A new species of Pseudocorax (Lamniformes, Pseudocoracidae), Pseudocorax heteroserratus n. sp., is described from the upper Maastrichtian phosphates of Morocco. This novel taxon is recognized by a large sample of isolated teeth collected from the upper Couche III layer at the Sidi Chennane quarry in the Oulad Abdoun Basin, Khouribga Province, Morocco. P. heteroserratus is differentiated from other Pseudocorax species by bearing a mesiodistally elongated tooth base, broad crown, and highly variable serrations. The variability in number and extent of serrations along the carinae ranges from completely absent to fully serrated and finely to coarsely serrated, raising speculation on broader Pseudocorax phylogenetics and as to whether the genesis of serrations within Pseudocorax occurred in a singular progressive event or rather from two distinct events. The morphological variability within the new species highlights the importance of large sample sizes in selachian odontological studies using isolated teeth.

UUID: http://zoobank.org/a8e2d349-5b2e-4fdd-9e3e-a93a290bf875

Planamandibulus nevadensis n. gen n. sp. is a newly discovered exceptionally preserved Laurentian phosphatocopid crustacean described from the upper Windfall Formation (Furongian, Stage 10) in Nevada. Planamandibulus nevadensis has closest affinity with the Baltic and Avalonian taxon Cyclotron. Its occurrence in sedimentary facies associated with dysoxia on the Laurentian paleocontinent fills in a gap in the global distribution of phosphatocopid crustaceans, facilitating a paleoenvironmental synthesis of this Cambrian group. We assess 75 taxa from nine paleocontinental areas spanning Cambrian stages 3 to 10 (~521–486.9 Ma). Comparison of these data with paleoclimate model simulations suggests that phosphatocopid distribution is explained partly by biogeography and ocean temperature patterns. Dabashanella species (e.g., D. hemicyclica Huo et al., 1983) are found across the low paleolatitude (<35°) paleocontinents of East Gondwanan (Australia), South China, and the central Asian terranes, spanning marine shelf carbonates to deeper marine black shale lithofacies, but are absent from mid- and high-paleolatitude sites, suggesting a warmer water preference. A similar warm-water preference is inferred for endemic taxa (e.g., Ulopsis, Parashergoldopsis) of East Gondwana, and perhaps for the newly described Laurentian Planamandibulus. By contrast, the mid- to high-paleolatitude paleocontinents Baltica and Avalonia are characterized by Veldotron, Cyclotron, Bidimorpha, Waldoria, Vestrogothia, Falites, and Trapezilites species, which occur in deep-shelf, cooler-water settings, typically below storm wave base. Hesslandona species sensu lato occur in mid-depth (likely above storm-wave base) warm tropical marine waters but are more typically found in deeper shelf and cooler waters in mid to high paleolatitudes. Phosphatocopids are also associated with sedimentary deposits characteristic of low environmental oxygen concentrations; this is emphasized by a peak in occurrences in the Guzhangian (Miaolingian) and Paibian (Furongian) stages, around the interval of the Steptoean Positive Carbon Isotope Excursion (SPICE) and its associated expansion of anoxic water masses onto shallow marine shelves. Our data compilation and data–model comparison support the environmental preference of phosphatocopids for low-oxygen, but not anoxic, water masses, and the new occurrence of Planamandibulus is consistent with this pattern.

UUID: http://zoobank.org/f136f8bf-1ccf-46b0-8980-b88be8f9603d

Ophiuroids have been major components of marine seafloor communities since the early Paleozoic. Past paleontological studies, especially those dealing with Paleozoic specimens, have based taxonomic descriptions on whole-skeleton morphology while mostly overlooking disarticulated ossicles, causing a large gap in our knowledge of Paleozoic ophiuroids. Recent studies of Mesozoic and Cenozoic ophiuroids, however, have examined the fine-scale morphological details of ophiuroid arm plates and have documented useful characters for taxonomic assignment. Here, we use similar methods for examining disarticulated ophiuroids to describe a Late Mississippian (Serpukhovian) ophiuroid fauna based solely on dissociated ossicles, preserved as microfossils and sieved from shale samples collected from the Indian Springs Shale Member of the Big Clifty Formation in Sulphur, Indiana, USA. We describe 11 species in total, 10 of which are new to science: Umerophiura daki n. sp., Strataster lisae n. sp., Schoenaster limbeckae n. sp., Vandelooaster douglasi n. sp., Furcaster wardi n. sp., Furcaster mccantae n. sp., Furcaster coulombeae n. sp., Sulphaster odellettorum n. gen. n. sp., Covidaster medicus n. gen. n. sp., and Suchaster granulosus n. gen. n. sp. Also present are ossicles of Cholaster sp. indet. The assemblage described in this paper significantly increases the known ophiuroid diversity in the Mississippian, yielding more species than all previous reports on Mississippian ophiuroids combined. Furthermore, our study shows that the evolution of the modern ophiuroid clade began much earlier than expected. Our results imply that the microfossil record of ophiuroids is paramount to unveiling the true paleobiodiversity of this evolutionarily important echinoderm clade.

UUID: http://zoobank.org/21fc0302-5a9f-41de-b1e3-6972de4b57bc

The phylogeny of the highly diverse bivalve order Venerida can be traced back to the Triassic, thanks to the well-understood evolution of its hinge system. I here suggest that the Early or Middle to Late Triassic genus Pseudocorbula is at the root of this phylogenetic lineage. The hinge of Pseudocorbula is primitive relative to the Early Jurassic Eotrapezium in the lack of a chevron-shaped AII–2b complex below the umbo of the left valve. However, both Pseudocorbula and Eotrapezium lack cardinal tooth 3a in the right valve. It is suggested that this lack stimulated the evolution of cardinal tooth 1, which first appeared as a small tubercle at the posterior end of lateral tooth AI that fits below the AII–2b complex; this early stage evolved into the well-known veneroid hinge with a differentiated cardinal tooth 1 in the pivotal position below the umbo of the right valve and the 2a–2b pair of cardinal teeth in the left valve. Pseudocorbulinae new subfamily is proposed for taxa that represent the earliest stage of veneroid hinge evolution, which is placed in Isocyprinidae. This phylogenetic hypothesis extends the roots of Venerida back to the Early or early Middle Triassic, a time that also saw the first appearance of oysters and modern scallops.

UUID: http://zoobank.org/1ba1e7c4-a6c1-4fb2-9e4c-2c1097649365

The evolutionary history of freshwater sponges (Porifera: Spongillida) in Australasia is poorly understood due to a paucity of fossils. A new genus and new species, Protooncosclera zealandiae n. gen. n. sp., family Potamolepidae, was discovered in southern New Zealand from lacustrine diatomites/spiculites of latest Oligocene–earliest Miocene of the Fossil-Lagerstätte at Foulden Maar. The fossil spicular complement is similar to that of the extant genus Oncosclera but differs from that and all other Spongillida genera by possessing a structured gemmular architecture armed by ornamented strongyles and strongyloxeas, with theca surrounded by a spicular cage of slender acanthoxeas, and a skeletal spicular complement of stout, smooth to spiny oxeas. This is the first fossil (pre-Quaternary) record of freshwater sponges from Australasia and fits into the Gondwana-like distribution of potamolepid freshwater sponges. Its discovery in a subtropical maar lake on the southwestern margin of Zealandia confirms a formerly wider geographic distribution of Potamolepidae in the Cenozoic, followed by range retractions related to post-Early Miocene climate cooling. The stratigraphic distribution of sponge remains at Foulden Maar demonstrates that sponges colonized the isolated maar lake soon after its formation, most likely by passive dispersal by water birds, and then thrived in the shallow water margins of the paleolake for ca. 130,000 years. Sponge remains, skeletal spicules and gemmules, frequently associated with coprolites indicate that sponges were consumed by one or more spongivorous taxa, presumably fish belonging to the Southern Hemisphere family Galaxiidae.

UUID: http://zoobank.org/72a81923-9766-4ae0-b980-28b2e3d98ebe

In discussions on European Neogene continental chronology, the Kastellios Hill section has played an important role because of the presence of strata with planktonic foraminifers and strata with mammalian remains. With the primary papers written in the 1970s and 1980s, the time is ripe for an update on age and taxonomy of the murid rodents from Kastellios Hill by comparing the fauna with time-equivalent southern and central European faunas. This comparison results in a partly revised faunal list consisting of the dominant Progonomys mixtus n. sp., the less common Cricetulodon cf. C. hartenbergeri Freudenthal, 1967 and P. cathalai Schaub, 1938, and the rare P. hispanicus Michaux, 1971 and cf. Hansdebruijnia neutra (de Bruijn, 1976). Based on the updated species list and magnetic polarity data, the most probable age of the Kastellios Hill mammal localities is 9.3–9.1 Ma (Chron C4Ar.1r, late Vallesian, MN10). The genus Hansdebruijnia is narrowed down to two species in an ancestor–descendant relationship: the ancestral type species H. neutra, which is restricted to southeastern Europe and Anatolia, and the descendant species H. magna (Sen, 1977), representing a new combination and including ‘Occitanomys alcalai’ Adrover et al., 1988 and ‘O. debruijni’ (Hordijk and de Bruijn, 2009). H. magna colonized both southeastern and southwestern Europe.

UUID: http://zoobank.org/ebe0f64c-6900-4efc-ab43-8a4045de6810

The Proetida likely represent the only surviving trilobite clade past the Devonian mass extinction event(s). Although members of order Proetida have long been studied, the global phylogenetic relationships across this pivotal time are still unresolved. I used a Bayesian phylogenetic approach to construct a subordinal level tree for members within the superfamily Proetoidea. Two models, a relaxed and strict clock model, were compared and used to assess past reconstructions of clades within the order. The trees from both models highlight key relationships among proetides across the Devonian and show paraphyly in groups that have been considered monophyletic in the past. Trees from both models also suggest that major groups, e.g., the genus Gerastos Goldfuss, 1843 and the family Phillispidae (which represents the most diverse post-Devonian proetide group under current taxonomic schemes) are polyphyletic. This in turn suggests, in a paleobiological context, a more complex pattern of survivorship over the Late Devonian than previously suggested as well as pervasive parallelisms toward certain ‘Gerastos’ or ‘phillipsid’ morphotypes.

The Cambrian Explosion saw the widespread development of mineralized skeletons. At this time, nearly every major animal phylum independently evolved strategies to build skeletons through either agglutination or biomineralization. Although most organisms settled on a single strategy, Salterella Billings, 1865 employed both strategies by secreting a biocalcitic exterior shell that is lined with layers of agglutinated sediments surrounding a central hollow tube. The slightly older fossil, Volborthella Schmidt, 1888, shares a similar construction with agglutinated grains encompassing a central tube but lacks a biomineralized exterior shell. Together these fossils have been grouped in the phylum Agmata Yochelson, 1977, although no phylogenetic relationship has been suggested to link them with the broader metazoan tree, which limits their contribution to our understanding of the evolution of shells in early animals.

To understand their ecology and place them in a phylogenetic context, we investigated Salterella and Volborthella fossils from the Wood Canyon and Harkless formations of Nevada, USA, the Illtyd Formation of Yukon, Canada, and the Shady Formation of Virginia, USA. Thin-section petrography, acid maceration, scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, and X-ray tomographic microscopy were used to provide new insights into these enigmatic faunas. First, morphological similarities in the aperture divergence angle and ratio of central tube diameter to agglutinated layer thickness suggest Salterella and Volborthella are related. Second, both fossils exhibit agglutinated grain compositions that are distinctive from their surrounding environments and demonstrate selectivity on the part of their producers. Finally, the calcitic shell composition and simple layers of blocky prismatic shell microstructure in Salterella suggest a possible cnidarian affinity. Together these data point to these organisms being sessile, semi-infaunal filter or deposit feeders and an early experimentation in cnidarian biomineralization chronicling a hypothesized transition from an organic sheath in Volborthella to a biomineralized shell in Salterella.

Pelmatozoa is an informal grouping of filter-feeding echinoderms including crinoids, paracrinoids, rhombiferans, and eocrinoids that possess a theca, an erect stalk, and feeding appendages. Although crinoids were major constituents of marine communities with high diversity and abundance throughout the Paleozoic, most other pelmatozoans had relatively low species diversity and/or short temporal durations. It has been proposed that these different diversification trajectories could have resulted from crinoids outcompeting other filter-feeding pelmatozoans during the early Paleozoic, although this hypothesis involving niche overlap has never been formally tested. Here, we tested this hypothesis using the incredibly diverse pelmatozoan fauna of the Late Ordovician (Sandbian) Bromide Formation of Oklahoma, which preserves a rich, ecologically complex fauna that developed as a result of the Great Ordovician Biodiversification Event. We developed a framework to quantitatively characterize pelmatozoan feeding ecology using multivariate analysis of ecomorphological traits and explored niche space occupation and potential competition between crinoids, rhombiferans, paracrinoids, eocrinoids, and diploporans from the Bromide fauna. Results revealed key ecological factors controlling niche differentiation and showed that crinoids, paracrinoids, and rhombiferans occupy nonoverlapping regions of niche space, indicating competition between groups was unlikely. Although the competition hypothesis was not supported, narrow niche space occupation suggests that paracrinoids and rhombiferans were more ecologically limited than crinoids, which might have played a role in their differential diversification dynamics. These results elucidate both the nature of interactions between pelmatozoan taxa and the potential mechanisms driving their evolutionary trajectories, as well as the complexity of ecological communities that arose during the Ordovician radiation.