A new trace fossil, Feoichnus martini new ichnospecies, from the Two Medicine Formation is here described. This ichnotaxon is reported from the upper Campanian deposits of the Egg Mountain locality (Montana) and consists of a hemispherical to hemiellipsoidal structure with a truncated upper edge, and a regular, rounded lower edge marked by a lined border composed of stained layers. The trace maker likely impregnated the border using organic fluids. The simple lined wall observed in F. martini n. isp. suggests that the structure was produced by an invertebrate soil-dwelling organism, likely an insect. Specimens are preserved as casts in calcitic Inseptisols alongside an abundant vertebrate fossil record composed by dinosaurian and nondinosaurian fossil remains, dinosaur eggs and nest structures, and pervasive insect bioturbation. Feoichnus martini n. isp. represents an additional, minor component of the impoverished Celliforma ichnofacies reported at Egg Mountain and expands the paleogeographical distribution of the ichnogenus Feoichnus Krause et al., 2008 to the Upper Cretaceous deposits of Montana, USA.

UUID: http://zoobank.org/7c1a5026-7f27-4f12-a9fb-1eb8daa93baf

Three new species of Cyphaspides are proposed: C. ammari, C. nicoleae, and C. pankowskiorum. These species are based on specimens obtained from Middle Devonian (Eifelian) strata of the Bou Tchrafine Group, near Erfoud, in the Province of Errachidia, southeastern Morocco. The present contribution enhances our knowledge of Cyphaspides by providing details of three new species that are based on well-preserved, complete, and articulated types. The genus Cyphaspides is discussed, and an emended diagnosis is provided. The paleobiogeography, ontogeny, and relationships of the genus are discussed.

UUID: http://zoobank.org/4a7aab8f-8c8e-4498-9cc2-6f8c69b85213

Since the end of the nineteenth century, many paleontological studies have been developed on the Middle Triassic localities of the Monte San Giorgio area (Canton Ticino, Switzerland, and Lombardy, Italy). These localities were inscribed in 2003 and 2010 in the UNESCO World Heritage List due to their paleontological relevance. New crustaceans are here described from the Kalkschieferzone member of the upper Ladinian Meride Limestone, outcropping near Besnasca-Cà del Frate (Viggiù, Italy) and Meride (Mendrisio, Switzerland). Several hundred specimens of a new genus and new species of Lophogastrida, named here Vicluvia lombardoae, improve information on Triassic mysidaceans (sensu lato), a group of shrimp-like crustaceans presently including hundreds of species worldwide distributed in marine and freshwater environments. The paper discusses the relations between Vicluvia n. gen. and the other fossil genera belonging to the same family. Vicluvia lombardoae n. gen. n. sp. exhibits two dorsally vanishing transverse grooves with their branches regularly bending toward the posterior margin of the shield and a telson with a rounded and setose apex. It was probably a euryhaline species living in a transitional environment affected by frequent and ephemeral salinity variations. Middle Triassic taphonomic windows have preserved specimens of lophogastrids in shallow basins along the Tethys, from the present Alps to China as well as in the German Basin.

UUID: http://zoobank.org/1623e8f9-2ceb-4cd6-bcbe-4f05a873e1ff

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.

UUID: http://zoobank.org/b5e613f1-c211-4676-8967-5a38a7d8d40e

Rhenopyrgids are rare, turreted edrioasterid edrioasteroids from the lower Paleozoic with a distinctive and apparently conservative morphology. However, new, well-preserved rhenopyrgid edrioasteroid material from Canada, along with a review of described taxa, has revealed broader structural diversity in the oral surface and enabled a re-evaluation of rhenopyrgid functional morphology and paleoecology.

The floor plates in Rhenopyrgus viviani n. sp., R. coronaeformis Rievers, 1961 and, R. flos Klug et al., 2008 are well fused to each other and the interradial oral plate and lack obvious sutures, thereby forming a single compound interradial plate. This differs from other rhenopyrgids where sutures are more apparent. Such fused oral surface construction is only otherwise seen in some derived edrioblastoids and in the cyathocystids, suggesting homoplasy.

Our analysis further suggests that the suboral constriction could contract but the flexible pyrgate zone could not. Thus, specimens apparently lacking a sub-oral constriction should not necessarily be placed in separate genera within the Rhenopyrgidae. It also supports rhenopyrgids as epifaunal mud-stickers with only the bulbous, textured, entire holdfasts (coriaceous sacs) anchored within the substrate rather than as burrow dwellers or encrusters.

Rhenopyrgus viviani n. sp. is described from the Telychian (lower Silurian) Jupiter Formation of Anticosti Island, Québec, Canada and is differentiated by a high degree of morphological variability of pedunculate plates, broader oral plates, and narrower distal ambulacral zones. Specimens lacking or with obscured diagnostic plates from the Ordovician of Montagne Noire, France, and the Ordovician and Silurian of Girvan, Scotland are also described.

UUID: http://zoobank.org/7f81d67f-4155-4719-8a45-b278ad70739d

Abundant new material of articulated asteroids from the Taba Starfish Bed (Lower Cretaceous, Barremian) of the Agadir Basin, western Morocco, allows reappraisal of this important fauna, and the recognition, to date, of five taxa belonging to the Astropectinidae, Odontasteridae, Goniasterididae, Terminasteridae, and Asteriidae. Betelgeusia orientalis Blake and Reboul, 2011 is shown to be a junior synonym of Coulonia platyspina Hess and Blake, 1995, and Dipsacaster africanus Blake and Reboul, 2011 comprises material of C. platyspina and a new odontasterid, here described as Odontaster tabaensis n. sp. Alkaidia megaungula n. sp. is described and its ontogeny and affinities discussed. From this, it is concluded that the Terminasteridae, revised to include the genera Terminaster and Alkaidia, is sister taxon to the extant family Zoroasteridae, and both are placed in the suborder Zorocallina of the Forcipulatida. The Taba fauna is a representative of a distinctive Lower Cretaceous asteroid assemblage that existed in northern Tethys from the Barremian to the Cenomanian and is also well known from the Albian and lower Cenomanian of Texas.

UUID: http://zoobank.org/b2ecdd06-685d-4242-9e49-985f9d7a3cc1

In contrast to almost all other invertebrate phyla that constructed biomineralized skeletons during the “Cambrian explosion” and maintained them during the entire fossil record, ascidian tunicates evolved this protective and stabilizing advantage only during the Permian, although soft-bodied representatives of this subphylum made their first appearance already in the early Cambrian. It remains enigmatic why these compound calcareous skeletons persisted only until the Late Triassic, subsequently followed by less-rigid internal skeletons from the Lower Jurassic onwards, which consist of scattered isolated spicules only. In addition to recently described aragonitic ascidian exoskeletons from the Permian and Triassic, new discoveries of similar, but colonial ascidian compound endoskeletons in the lower Carnian exhibit a short-living branch of this group, which moreover contain the first indubitable calcareous spicules. The latter are embedded in the solid endoskeleton, which is composed of polygonal aragonitic plates with smooth outer and zigzag lined inner boundaries. They consist of irregular, parallel (orthogonal), or fan-shaped (clinogonal) arrangements of acicular aragonite crystals. The following taxa are described as new: order Cassianomorpha new order with the family Cassianosomidae new family and the genus Toscanisoma new genus with the species T. multipartitum new species and T. triplicatum new species.

UUID: http://zoobank.org/03555353-cdab-42e8-8e99-9bfce15fa249

The Rio Grande do Sul Coastal Plain (southern Brazil) is composed of extensive marine and continental deposits related to at least four lagoon-barrier systems of Pleistocene−Holocene age. Part of these deposits is currently submerged and passing through erosion processes by waves. Vertebrate and invertebrate body and trace fossils are constantly exhumed from these deposits and redeposited on the modern beach face. Among them, a total of 253 fragments of crustacean burrows were collected for this study. Two ichnospecies of Ophiomorpha Lundgren, 1891 were recognized (O. nodosa Lundgren, 1891 and O. puerilis Gibert et al., 2006), but most of the materials can only be assigned to the ‘SOT’ group (Spongeliomorpha de Saporta, 1887, Ophiomorpha, and Thalassinoides Ehrenberg, 1944), mainly because of the lack of a pelleted lining. The absence of pellets and, as a consequence, the ichnotaxonomy of these specimens, is related to taphonomical processes (exhumation, reworking, and transportation) that acted during formation of the ex situ assemblage. The paleoenvironmental dynamics and a taphonomical model are presented to demonstrate how these processes affected the trace fossils since their construction, through exhumation until deposition. Neoichnological observations led us to infer larger producers in comparison to the extant ghost shrimp Sergio mirim (Rodrigues, 1971).

An incomplete arthropod fossil, Tricarina gadvanensis Feldmann et al., 2007, from the Lower Cretaceous (Barremian–Aptian) of Iran, originally interpreted as a lobster (Malacostraca, Eucarida, Decapoda), is reinterpreted herein as a representative of a seroloid isopod crustacean (Malacostraca, Peracarida, Isopoda). The body orientation of the fossil is reversed, and the alleged cephalothoracic shield is reinterpreted as being the pleotelson. Tricarina gadvanensis, with its unique configuration of pleonite fusion (pleonites 1–4 are free, whereas pleonite 5, with still visible epimera, is fused with the pleotelson), is suggested to represent a close relative of Serolidae. The preservation of T. gadvanensis in deepwater shales speaks for conservativeness in environmental preferences of seroloid isopods for at least 125 million years.

The Kalana Lagerstätte of early Aeronian (Llandovery, Silurian) age in central Estonia preserves a diverse shallow marine biota dominated by non-calcified algae. This soft-tissue flora and decalcified and calcified crinoids are preserved in situ, in a lens of microlaminated, dolomitized micrite interbedded in a sequence of dolomitized packstones and wackestones. Although the Lagerstätte is dominated by non-calcified algae, crinoids (together with brachiopods and gastropods) are among the most common organisms that were originally comprised of a carbonate skeleton. Two new crinoids are described from this unit, Kalanacrinus mastikae n. gen. n. sp. (large camerate) and Tartucrinus kalanaensis n. gen. n. sp. (small disparid). Interestingly, these two crinoids display contrasting preservation, with the more common large camerate preserved primarily as a decalcified organic residue, whereas the smaller disparid is preserved primarily in calcite. Preservation was assessed using elemental mapping of C, Ca, S, and Si. Columns have the highest portion of Ca, once living soft tissue is indicated by C, S was dispersed as pyrite or associated with organics, and Si is probably associated with clay minerals in the matrix. This new fauna increases our understanding of the crinoid radiation on Baltica following Late Ordovician extinctions.

UUID: http://zoobank.org/fb1f98c4-d35a-43f4-aa0d-75e4f8154a13

Intermediate morphologies of a new fossil crinoid shed light on the pathway by which crinoids acquired their distinctive arms. Apomorphies originating deep in echinoderm history among early nonblastozoan pentaradiate echinoderms distinguish Tremadocian (earliest Ordovician) crinoid arms from later taxa. The brachial series is separated from the ambulacra, part of the axial skeleton, by lateral plate fields. Cover plates are arrayed in two tiers, and floor plates expressed podial basins and pores. Later during the Early Ordovician, floor plates contacted and nestled into brachials, then were unexpressed as stereom elements entirely and cover plates were reduced to a single tier. Incorporation of these events into a parsimony analysis supports crinoid origin deep in echinoderm history separate from blastozoans (eocrinoids, ‘cystoids’). Arm morphology is exceptionally well-preserved in the late Tremadocian to early Floian Athenacrinus broweri new genus new species. Character analysis supports a hypothesis that this taxon originated early within in the disparid clade. Athenacrinus n. gen. (in Athenacrinidae new family) is the earliest-known crinoid to express what is commonly referred to as ‘compound’ or ‘biradial’ morphology. This terminology is misleading in that no evidence for implied fusion or fission of radials exists, rather it is suggested that this condition arose through disproportionate growth.

UUID: http://zoobank.org/b383e039-3298-4472-a7e3-e81684f87cfe

Brochuchus is a small crocodylid originally based on specimens from the early Miocene of Rusinga Island, Lake Victoria, Kenya. Here, we report occurrences of Brochuchus from several early and middle Miocene sites. Some are from the Lake Victoria region, and others are in the Lake Turkana Basin. Specimens from the middle Miocene Maboko locality form the basis of a new species, Brochuchus parvidens, which has comparatively smaller maxillary alveoli. Because of the smaller alveoli, the teeth appear to be more widely spaced in the new species. We also provide a revised diagnosis for Brochuchus and its type species, B. pigotti. A phylogenetic analysis supports a close relationship between Brochuchus and tube-snouted Euthecodon, but although relationships among crocodylids appear poorly resolved in the set of optimal trees, this is because Brochuchus and Euthecodon, along with early Miocene “Crocodylus” gariepensis from the early Miocene of Namibia, jointly adopt two distinct positions—either closely related to the living sharp-nosed crocodile (Mecistops) or to a group including the living dwarf crocodiles (Osteolaemus). Character support for a close relationship with Mecistops is problematic, and we suspect a closer relationship to Osteolaemus will be recovered with improved sampling, but the results here are ambiguous. In either case, Brochuchus is more closely related to living groups not currently found in East Africa. This material helps constrain the timing of crocodylian faunal turnover in the East African Rift Valley System, with endemic lineages largely being replaced by Crocodylus in the middle or late Miocene possibly in response to regional xerification and the replacement of continuous rainforest cover with open grasslands and savannas.

UUID: http://zoobank.org/e6f0b219-5f3e-44e5-bdb9-60a4fae8d126

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, Schoenaster Meek 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.

UUID: http://www.zoobank.org/ffd945d8-63ac-4c38-a2d3-8647558dbbf0

This report documents the last pteraspids, (armored, jawless members of the Heterostraci), which are otherwise only known from the Early Devonian of the Old Red Sandstone Continent. Tuberculate pteraspid heterostracans are described from the Middle Devonian beds of two formations in western North America. The late Givetian Yahatinda Formation of Alberta and British Columbia consists of channels cut into lower Paleozoic rocks and represents deposition in marine to littoral environments. Clavulaspis finis (Elliott et al., 2000a) new combination is redescribed from additional material from the Yahatinda Formation and reassigned to the new genus Clavulaspis because the original genus name is invalid. The Eifelian Spring Mountain beds of Idaho consist of a large channel that represents a clastic-dominated estuarine environment. It contains Scutellaspis wilsoni new genus new species, and the previously described species from the Spring Mountain beds is redescribed and reassigned to Ecphymaspis new genus, which was prompted by new material and a review of the validity of the original genus name. Phylogenetic analysis shows that these three new taxa form part of the derived clade Protaspididae.

UUID: http://zoobank.org/9cf09b21-cec1-4ce4-bc2b-658d0b515e10

The latest Ordovician to earliest Silurian graptolite Avitograptus avitus is important in the biostratigraphy of the Ordovician–Silurian boundary interval. Two additional species of Avitograptus are described from the sponge-dominated Anji Biota of the Upper Ordovician Wenchang Formation (Metabolograptus persculptus Biozone) of Zhejiang Province, South China. One species, Avitograptus akidomorphus new species, is new; the other, Avitograptus acanthocystus new combination, which was previously placed in Climacograptus, is herein assigned to Avitograptus. The former species may represent the ancestral akidograptid because it is identical in thecal form to Akidograptus, but differs in the development of the proximal end. The evolutionary changes from Avitograptus avitus to Akidograptus and Parakidograptus involved distal movement of the origins of th11 and th12, thecal elongation, and greater outward inclination of the thecal walls.

UUID: http://zoobank.org/81c433a0-9069-48d2-ae72-1267400cbf77.

Neusticemys neuquina (Fernández and de la Fuente, 1988) is a turtle from the Upper Jurassic of the Neuquén Basin, Patagonia, Argentina. Here we describe in detail a new skull, lower jaw, and a vertebra, utilizing both traditional anatomical description and computed tomography (CT). New diagnostic cranial characters of Neusticemys neuquina are: a round depression on the ventral surface of the basisphenoid, a relatively larger oval foramen nervi trigemini, and reduced and steepened triturating surfaces on both the maxilla and dentary. The new morphological information presented in this study was included in a phylogenetic analysis, the primary result of which was recovery of Neusticemys neuquina within Thalassochelydia. Characters recognized as synapomorphies of this clade include: (1) anterolateral recess of the anterior surface of the quadrate positioned lateral to the processus trochlearis oticum, (2) presence of a fossa on the supraoccipital-opisthotic-exoccipital contact area, (3) foramina anterius caroticus cerebralis located close together but independently perforating the basisphenoid, and (4) the presence of the splenial in the mandible. Two contrasting dispersal scenarios could explain how this species of Thalassochelydia can be found outside of Europe. The presence of Neusticemys neuquina in the Neuquén Basin could be the consequence of an early dispersion event, for which we lack intermediate forms, or it could be the result of a later event once the clade was already established in Europe.

Upper Ordovician (Katian) strata of the Lake Simcoe region of Ontario record a spectacularly diverse and abundant echinoderm fauna known as the Brechin Lagerstätte. Despite recognition as the most taxonomically diverse Katian crinoid paleocommunity, the Brechin Lagerstätte has received relatively little taxonomic study since Frank Springer published his classic monograph on the “Kirkfield fauna” in 1911.

Using a new collection of exceptionally preserved material, we evaluate all dicyclic inadunate crinoids occurring in the Brechin Lagerstätte, which is predominantly comprised of cladids (Eucladida and Flexibilia). We document 15 species across 11 genera, including descriptions of two new genera and four new species. New taxa include Konieckicrinus brechinensis n. gen. n. sp., K. josephi n. gen. n. sp., Simcoecrinus mahalaki n. gen. n. sp., and Dendrocrinus simcoensis n. sp.

Although cladids are not commonly considered major components of the Early Paleozoic Crinoid Macroevolutionary Fauna, which is traditionally conceived as dominated by disparids and diplobathrid camerates, they are the most diverse major lineage of crinoids occurring in the Brechin Lagerstätte. This unexpected result highlights the important roles of specimen-based taxonomy and systematic revisions in the study of large-scale diversity patterns.

UUID: http://zoobank.org/09dda7c2-f2c5-4411-93be-3587ab1652ab

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.

UUID: http://zoobank.org/3a1580d1-a2f4-49b6-8170-69a778c49181

A large sample (>100 specimens) of the fossil rodent Thisbemys Wood, 1959, from the early Eocene (late Bridgerian; Br3) Washakie Formation of Wyoming is described. Two species are recognized: a new species, T. intermedius n. sp., and Thisbemys cf. T. uintensis (Osborn, 1895). The large sample size of the former has allowed for a detailed study of variation in size and morphology within the species based on tooth-wear. As a result, some systematic changes in the species included in this genus are suggested: (1) T. brevicrista Ostrander, 1986, is limited to the holotype, and all specimens previously referred to T. brevicrista are likely referable to T. plicatus Wood, 1962; (2) statistical analysis supports the separation of T. plicatus from T. corrugatus Wood, 1959, based on its smaller size and less-crenulated cheek teeth, which corroborates their existence at different horizons (T. plicatus earlier Bridgerian [Br2], T. corrugatus late Bridgerian [Br3]); (3) Paramys delicatior Leidy, 1871, is suggested as the senior synonym of T. plicatus Wood, 1962; (4) T. perditus Wood, 1962, is limited to the early Eocene (Washatchian: Wa1-6); and (5) all specimens previously referred to T. nini Wood, 1962, except the holotype, are referred to T. perditus (fide Korth, 1984; contra Anderson, 2015).

UUID: http://zoobank.org/59c101e2-cd55-4dce-aeea-3da48c4fbd53

Four placoderm fishes are described from the Lepel Beds of the Vitebsk Regional Stage of the Lower Devonian (upper Emsian) of Belarus. Two forms are new (Stipatosteus svidunovitchi new genus, new species and Actinolepis zaikai new species) and the other two taxa are left in open nomenclature (Coccosteidae gen. indet. sp. indet.; Placodermi indet. 1). Specimens of all four forms consist of disarticulated, mostly well-preserved plates (some are worn at the edges) originating from the cores of six boreholes. Additionally, the paper presents data on organic remains with the placoderms. A detailed lithological description of the enclosing rocks and a taphonomic description of the ichthyofauna are also provided. The 2010 Stratigraphic Chart of the Devonian deposits of Belarus was used as the stratigraphic basis. The presence of the genus Actinolepis Agassiz, 1844 in these deposits as well as in the Emsian of the Baltic region and Spitsbergen suggests a regional paleogeographic connection at this time.

UUID: http://zoobank.org/368b44df-e9e9-417c-a0e0-f7e138b7f4ec