A low diversity fauna of microscopic crinoids from the Kinderhookian (Mississippian) McCraney Limestone at Seehorn Hollow, western Illinois, is described and illustrated by stereomicrographs. The crinoids include first record of the camerate crinoid genus Hexacrinites (H. mississippiensis n. sp.) above the Devonian. The other three taxa are all inadunates and include the monocyclic microcrinoid Allagecrinus mccraneyensis n. sp., which has up to 14 arms, and two dicyclic poteriocrinoids, Hypselocrinus maccabei (Miller and Gurley, 1894) and an indeterminate genus of the Scytalocrinidae.

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

A Glyptagnostus reticulatus (Angelin, 1851)–bearing trilobite assemblage has been found from an unnamed Cambrian formation in the Northern Qilian Mountains area, of which geographical placement in the Cambrian is contested. Glyptagnostus reticulatus is a biostratigraphic indicator of the Furongian Series and Paibian Stage, and three agnostoid and six polymerid taxa from the Changgou section, Daliang area are described herein, along with conspecific forms from the nearby Chuancigou section. This well-preserved assemblage shows strong taxonomic affinity with northwestern Queensland, Australia, and western Hunan–eastern Guizhou, China, and likely comes from deep outer-shelf to slope setting associated with the Northern Qilian arc. It is consistent with other arguments that during the Cambrian, the Northern Qilian arc, along with the Hexi Corridor of the Alxa terrane, were more closely allied to South China than to North China.

A new species of Apiocrinites is described from the Middle Jurassic (Callovian) Matmor Formation of the Negev, Israel. Apiocrinites negevensis is from the tropical latitudes in the Tethys, in contrast to all other reported species of this genus. With a narrow radial facet and adjacent arms not in lateral contact and large aboral cup plates, A. negevensis is quite unusual for this genus.

The trilobite fauna of the middle Silurian (Telychian to possibly earliest Sheinwoodian) Tomcat Creek limestone in the Broken River Province of north Queensland is dominated by the suborder Illaenina, including illaenimorphs (Illaeninae and Bumastinae) and members of the Scutelluidae. Scutelluidae are most diverse, with eight genera, of which Dolabrapex, Iotoryx, Perizostra, and Quintonia are new. Perizostra is the first scutelluid with a cephalon that may be described as of phacomorph appearance. Illaenimorphs are represented by three genera, including Opsypharus, which is regarded as a senior synonym of Paracybantyx but distinct from Failleana with which it has been placed in synonymy by some authors. Thirteen species are new: Cybantyx? ergodes, Opsypharus pandanensis, Australoscutellum talenti, Dolabrapex acomus, Illaenoscutellum psephos, Iotoryx clarksoni, Japonoscutellum mawsonae, J. drakton, J. fractum, Kosovopeltis avita, Perizostra campbelli, Quintonia arata, and Q. pavo. A species of Stenoparia is placed in open nomenclature. The species of Australoscutellum, Illaenoscutellum, and possibly Kosovopeltis are the oldest known representatives of those genera. These genera and Japonoscutellum are also common in faunas from limestones of Wenlock to Ludlow age in central western New South Wales, reflecting the similarity in lithofacies. The monotypic Late Ordovician genus Craigheadia, which has been regarded as a scutelluid, belongs to the Lichidae and is probably a junior synonym of Leiolichas.

Unique among the Rugosa are specialized cyst-like structures in corals from an upper Carboniferous limestone within the Baird Formation in the Klamath Mountains, northern California. These structures, here referred to as septal cysts, occur mostly along the distal margins of the dark line extending along the axes of the major septa as seen in transverse section. However, they also commonly extend beyond the distal extent of those lines and may interrupt the fibrous coating in the more proximal parts of some septa. Their function is uncertain. Also present are small dissepiments which form a ring around the distal margins of the minor septa. These structures, however, do not appear to be related to the development of those septa. Some other taxa, including corals from the Bashkirian of Spain and the Kasimovian of Kansas, possess some specialized structures similar to those in the California specimens suggesting at least a remote relationship.

Macro- and microfossils are commonly preserved as external molds as a result of decay or dissolution of soft and mineralized body parts after compaction and cementation of the surrounding matrix. The molds, which often preserve external features of the organism in great detail, are difficult to compare to other specimens. To enhance study, positive casts are typically made. Numerous compounds can serve as a casting medium (Rigby and Clark, 1965; Rixon, 1976). In microfossil studies latex rubber (Klapper in Winder, 1966; Ellison, 1987; Tull et al., 1988) and silicone rubber (G. Miller, personal commun.) are the most commonly used materials. An alternative technique is to photograph the mold directly using a scanning electron microscope (SEM).

Decimeter-scale, elongate, fossil fronds from the Ediacara Range in South Australia were formally described as Rangea longa Glaessner and Wade, 1966, but the disparate nature of documented specimens has hindered their inclusion in global syntheses and has resulted in these fossils being assigned to at least five different genera in two different clades since their discovery. Detailed study of the type material from the Ediacara Range and the few specimens subsequently collected elsewhere in the Flinders Ranges reaffirms that these specimens represent a single species, with the apparent morphological variation between specimens entirely taphonomic and reflecting the obverse and reverse surfaces of these fronds coupled with the orientation of the frond axis and petaloids at different angles relative to the sea bottom on which they were preserved. The preserved architecture of these fronds constitutes three orders of branching microstructure that are strictly orthogonal to immediately higher and lower orders. This implies affinities with the arboreomorphs, but representing a new frond genus herein named Akrophyllas. Akrophyllas n. gen. differs from all other Ediacaran fronds in exhibiting a stalk that is visible only on one side of the frond and is internal to the other side where the first-order branches instead meet at a zigzag axial trace. Akrophyllas n. gen. was attached to a bulbous holdfast on the sea bottom, and evidence for current scours that formed in the lee of the fronds and for a strong current alignment of felled fronds with depositional overlap of adjacent fronds imply an upright, epibenthic lifestyle for Akrophyllas longa new combination.

UUID: http://zoobank.org/86e26477-7b1e-45da-870c-1b5d28fc510c

The study of the cranial endocast provides valuable information to understand the behavior of an organism because it coordinates sensory information and motor functions. In this work, we describe for the first time the anatomy of the encephalon of an early Miocene pan-octodontoid caviomorph rodent (Prospaniomys priscus Ameghino, 1902) found in the Argentinean Patagonia, based on a virtual 3D endocast. This fossil rodent has an endocast morphology here considered ancestral for Pan-Octodontoidea and other South American caviomorph lineages, i.e., an encephalon with anteroposteriorly aligned elements, mesencephalon dorsally exposed, well-developed vermis of the cerebellum, and rhombic cerebral hemispheres with well-developed temporal lobes. Prospaniomys Ameghino, 1902 also has relatively small olfactory bulbs, large paraflocculi of the cerebellum, and low endocranial volume and degree of neocorticalization. Its encephalization quotient is low compared with Paleogene North American and European noncaviomorph rodents, but slightly higher than in several late early and late Miocene caviomorphs. Paleoneurological anatomical information supports the hypothesis that Prospaniomys was a generalist caviomorph rodent with terrestrial habits and enhanced low-frequency auditory specializations. The scarce paleoneurological information indicates that several endocast characters in caviomorph rodents could change with ecological pressures. This work sheds light on the anatomy and evolution of several paleoneurological aspects of this particular group of South American rodents.

Toyotamaphimeia is an extinct crocodylian lineage whose name is derived from a mythological Japanese princess. Here, we re-examine the type specimens of a long-forgotten species: Tomistoma taiwanicus from the Pleistocene of Tainan (Taiwan) and revise its taxonomic status to Toyotamaphimeia taiwanicus n. comb., leading to the first recognized species of Toyotamaphimeia outside Japan. Our phylogenetic analyses also support this taxonomic assignment and, more interestingly, further suggest an East Asian lineage. In addition, Toyotamaphimeia taiwanicus n. comb. represents a tropical species, resolving a long-standing puzzle of why Toyotamaphimeia only inhabited a much higher latitudinal area (Japan). Given the large body size of Toyotamaphimeia taiwanicus n. comb. (~7 m) and the fact that it is geologically older than Toyotamaphimeia machikanensis from Japan, we propose a novel evolutionary scenario: the genus Toyotamaphimeia originated in Taiwan and evolved to a large body size with gigantothermic physiology, which resulted in migration out of Taiwan and dispersal farther north to Japan. Our taxonomic identification shows the presence of an extinct endemic crocodylian species from the Pleistocene of Taiwan with large-scale paleogeographic implications. This study, with our recent progress in vertebrate paleontology in Taiwan, should provoke more in-depth paleontological research on the Pleistocene extinction.

Family-level taxonomic concepts for Paleozoic Asteroidea are problematic; data availability for the family Urasterellidae, however, is judged sufficient for familial reappraisal. The survey cannot be fully comprehensive because certain available names are founded on very limited material, with specimens widely scattered among collections. Recognized urasterellid genera include Urasterella Schuchert, 1914; Anthroosasterias Blake, 2017; Meturaster Blake, Guensburg, and Lefebvre, 2016; Salteraster Stürtz, 1893; Staurasterias Blake, 2017; Ulrichaster Spencer, 1950; and Pegoasterella pompom n. gen. n. sp. Other available generic names are held in abeyance. The name Urasterella has approached form-genus status, an outcome exacerbated by incomplete understanding of the type species. Urasterella huxleyi (Billings, 1865) is reassigned to Anthroosasterias. Relatively large specimen suites for Anthroosasterias huxleyi (Billings, 1865) and Salteraster grandis (Meek, 1872) enable some interpretation of urasterellid intrataxon variation, ontogenetic change, and life mode. Morphologic changes accompanying ontogeny of A. huxleyi are argued as favoring a shift from substrate surface feeding to feeding through extension of arms into the water column in a manner comparable to that seen among extant Forcipulatida and ophiurans.

UUID: http://zoobank.org/82d2eca7-55e0-42ed-a164-c666652e3972

Tiny sinuous trace fossils have been found within probable gut contents of an exceptionally preserved specimen of a hadrosaurid dinosaur, Brachylophosaurus canadensis, from the Judith River Formation of Montana. Approximately 280 examples of the trace fossils were observed in 19 samples of gut region material. The tubular structures typically are about 0.3 mm across. Many have thin calcareous linings or layers, and some exhibit fine surficial striae. At least two dozen of these trace fossils share walls with adjacent tubular traces, and this association can extend for several millimeters. While the trace fossils share some characteristics with fine rhizoliths, these features are most consistent with tiny burrows, or possibly body impressions, of worms (vermiform organisms) of uncertain biologic affinity. Such trace fossils have not been reported previously, and herein described as Parvitubulites striatus n. gen. n. sp. Either autochthonous (parasites) or allochthonous (scavengers) worms may have created the trace fossils, but taphonomic factors suggest that autochthonous burrowers are more likely. Several lines of evidence, such as constant diameters and matching directional changes, suggest that the paired trace fossils were made by two individuals moving at the same time, which implies sustained intraspecific contact. Parvitubulites striatus provides a rare record of interactions between terrestrial, meiofaunal-sized, soft-bodied invertebrates and a dinosaur carcass. The evidence that the worms may have parasitized a living hadrosaur and subsequently left traces of intraspecific behavior between individual worms adds unique information to our understanding of Mesozoic trophic interactions.

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

As many as eight species of the “anchitherine” equid Miohippus have been identified from the John Day Formation of Oregon, but no statistical analysis of variation in these horses has yet been conducted to determine if that level of diversity is warranted. Variation of the anterior-posterior length and transverse width of upper and lower teeth of Turtle Cove Member Miohippus was compared to that of M. equinanus, Mesohippus bairdii, Equus quagga, and Tapirus terrestris using t tests of their coefficients of variation (V). None of the t tests are significant, indicating that the variation seen in Turtle Cove Miohippus is not significantly different from any of the populations of other perissodactyls examined in this study. Data also indicate that Mesohippus is present in the Turtle Cove Member. Additionally, hypostyle condition, used to diagnose all species of Miohippus, was found to be related to stage of wear using an ordered logistic regression. Only two species of equid, one Miohippus and one Mesohippus, in the Turtle Cove Member can be identified, therefore only Miohippus annectens, the genotype and first species described from the region, can be recognized as the sole Miohippus species known from the Turtle Cove assemblage. There are insufficient data to determine which species of Mesohippus is present. The dependence of hypostyle condition on crown height in Miohippus implies that wear stage must also be considered in investigations of dental morphology in the “Anchitheriinae.”

The use of different methodological approaches together with an exhaustive qualitative study has helped to recognize important morphological traits to distinguish species in a systematic and phylogenetic framework. Parabolinella triarthroides Harrington, 1938 was described based on two cranidia from the Quebrada de Coquena, Purmamarca, Jujuy province. The generic assignment of P. triarthroides has been questioned by a phylogenetic analysis, which resolves this species as the sister group of Bienvillia Clark, 1924. To explore the generic assignment of this species, a revision of the type material, plus a morphometric analysis including specimens of Parabolinella Brøgger, 1882 and Bienvillia were performed. In addition, the original matrix used in the published phylogeny was reviewed and enlarged, including more species of Bienvillia. Continuous characters were coded in different ways in order to compare how they could affect the ordering of specimens and their phylogenetic relationships. Finally, both methodologies were compared, especially in regard to the behavior of the quantitative characters included in the analyses. From the combined analyses, it is shown that similarities between the cranidium of P. triarthroides and all other Parabolinella species are true homologies instead of a by-product of evolutionary convergence. Therefore, P. triarthroides should be considered a member of this genus. Finally, this study demonstrates that the best strategy for solving systematic problems in groups where the morphological variation is the only source of information (i.e., fossil taxa without living representatives) is the implementation of an integrative approach, combining different methodological techniques and a good description of specimens.

An extinct ictalurid catfish, Ictalurus spodius n. sp., is described from the Pleistocene of Central Mexico. It shares derived osteological characters with the subgenus Ictalurus and the I. punctatus species group. The new species is known from middle Pleistocene fluvial and lacustrine sediments and was abundant until near the end of the Pleistocene when it was replaced by a closely related species, I. dugesi. The latter is known from late and post-Pleistocene lake-bottom deposits and is widespread in Central Mexico today.

Proetid trilobites are described from three sections in two regions of southern Morocco. the sections are located at Jbel Gara el Zguilma (‘Zguilma’) and a neighboring section (‘near Zguilma’), near Foum Zguid; and at another locality (BD5) in the Ma'der Region, between the villages of bou Dib and Tazoulaït, near the town of Alnif. the trilobites described here are assigned to a proposed new genus, Timsaloproetus, with Cornuproetus (Sculptoproetus) haasi Alberti, 1971 as type species. Timsaloproetus haasi occurs in Eifelian strata of both Germany and Morocco (at BD5, and both of the sections near Foum Zguid). New Moroccan species of this genus are Timsaloproetus dibbanus and Timsaloproetus elguerrouji. the former occurs in upper Emsian strata at Zguilma, and the latter occurs in strata of early Eifelian age, with T. haasi, in both the Zguilma and near Zguilma sections.

The tricranocladine sponges (now assigned to the suborder Eutaxicladina) are a conservative group consisting of the single family Hindiidae. the genus Hindia Duncan is considered the base of the tricranoclad evolutionary record. A new sponge discovered from the Ordovician limestones of the San Juan Formation in the Argentine Precordillera allows a reexamination of the Hindiid lineage and extends the early history of the tricranocladines back to the Darriwilian. Eoscheiella concava n. gen. and sp. is described and illustrated. It is known from a single chertified, spherical specimen with a central hollow core, a typical character found in several genera of the family. Tricranoclads, megarhizoclones, and radial monaxonic spicules are the main skeletal components of the new genus. the presence of a band of subparalell tangential monaxons on the surface of Eoscheiella can be related to an inferred, small, root tuft that attached the spherical sponge to the substrate. the discovery of Eoscheiella modifies the evolutionary view of the family, for it is the oldest genus now known with simple dipodal and tripodal tricranoclads without a brachyome, radial monaxons, and megarhizoclones. Eoscheiella displaces the genus Hindia from the base of tricranocladine evolutionary history. Variability in spicule form, arrangement, and clasping possibilities observed in Permian representatives are clearly more accentuated in the Ordovician Eoscheiella. All these features appeared earlier than expected in previously proposed evolutionary trends.

A single specimen of the new sponge, Raphidonema indica n. sp., is the first Eocene sponge to be reported from India. It was collected from the Fulra Limestone Formation at Lakhpat, Kutch, India. The undulating, cup-like sponge is most similar to R. farringdonense (Sharpe, 1854), but the Indian species has a clustered, mounded excurrent system and numerous tangential canals on the upper, exhalant surface. Skeletal tracts in Raphidonema indica are 0.4–0.5 mm in diameter, in walls that are generally 12–14 mm, but range up to 18 mm thick.