The Lower–Middle Ordovician (Ibexian, Whiterockian) sedimentary rocks exposed at Rancho Las Norias includes the informally named Las Norias formation, which consists of an intercalation of carbonate and clastic sediments with abundant marine fauna. These deposits occur as the most austral sedimentary rocks of Ordovician age for Laurentia, providing a critical link to understand the distribution of Ordovician marine faunas of North America. An investigation of the gastropod fauna from the upper portion of the Las Norias formation, Sonora, Mexico, is undertaken for the first time. The gastropod assemblage includes Maclurites acuminatus, ?Monitorella sp., Lecanospira sp., Malayaspira aff. M. rugosa, Lophospira perangulata, and Hormotoma? sp. This assemblage indicates a paleogeographic relationship with Laurentia, including the USA (Nevada), Canada (British Columbia, Newfoundland), Greenland, and the Argentine Precordillera.

Based on abundant topotype specimens from the Oil Creek Formation at the type locality in southern Oklahoma, Histiodella labiosa is described and revised. The morphological variation of the Pa, Pb, and M elements of this previously little-known species is also systematically documented and illustrated. The revised species definition, with formal designation of a lectotype and a new diagnosis supported by morphological comparison with its ancestral and descendent species, has enhanced its value for correlation of the lower Darriwilian. The inferred phylogeny of Histiodella that resulted from this study is based on both cladistic and morphological analyses. It supports the monophyletic grouping of Histiodella species and their evolutionary relationships. This has wide biostratigraphic implications because many Histiodella species are valuable for detailed global correlation of upper Dapingian to middle Darriwilian strata.

Carnivores make traces on bones with their teeth when feeding. A true predatory bite trace (predichnia) forms when a predator catches and kills its prey or attempts to do so. Both predators and scavengers may leave their nonpredatory feeding traces during postmortem food processing. Despite the interpretative uncertainties as to the ethology such ichnofossils may represent, the bite traces have been traditionally classified as predichnia—traces of predation. Previously, there was no alternative ethological category available for workers to classify them. The present paper fills that gap and describes tooth-made ichnofossils from the continental Upper Triassic Grabowa Formation of southern Poland. It discusses modes the serration and striations might have formed along Linichnus edges, potential makers of the trace fossils, feeding strategies, and food-processing behaviors the ichnites may represent. All the bite traces are thought to act as a record of carnivorous behaviors and are classified as sarcophagichnia, a new ethological category (traces of feeding on a body). Finally, all the studied bite traces were likely inflicted postmortem and are classified as necrophagichnia (traces of feeding on an already dead body), most likely produced by scavengers in the studied cases. Data on recent carnivores link these ichnites with postmortem food-processing behaviors, such as dismembering and defleshing. Scavenging could, in fact, have been a preferred carnivorous feeding strategy in the seasonal Norian climate of the area. Dry seasons could have perhaps increased vertebrate mortality rates and provided plenty of carcasses for carnivores to feed on.

The extinct family Hylicellidae, as the ancestral group of modern cicadomorphans, had a wide distribution and a very high species-level biodiversity from the Triassic to Early Cretaceous. We herein report 11 new hylicellid specimens from the Jurassic Daohugou beds of Inner Mongolia, NE China, and execute geometric morphometric analysis (GMA) to elucidate their systematic position. Our GMA and subsequent morphometric statistics indicate that 10 of our new specimens can be compared to the holotype of Cycloscytina gobiensis, and one is new to science. Cycloscytina incompleta new species is erected based on this specimen, with the following discriminatory tegminal traits: C3 almost as long as and slightly narrower than C2, and the forking position of stem M distinctly migrates towards wing apex and much apicad of the stem CuA bifurcating. Additionally, Cycloscytina plachutai is herein transferred to the procercopid genus Procercopina, resulting in P. plachutai new combination. To date, just a few body structures of Hylicellidae have been revealed, and the new whole-bodied hylicellids reported herein provide some novel insights on the evolution of basal Clypeata. This study also emphasizes the use of morphometric analysis in the systematics of wing-bearing insects such as hylicellids.

UUID: http://zoobank.org/84a67eba-9b7c-4e27-a436-764802c4cdfb.

Predation is of great importance in understanding the diversification of spatangoid echinoids as well as their preservation in the fossil record. Herein, the spatangoid-dominated Miocene carbonate succession of Punta Foghe (Montiferru area, central-western Sardinia, Italy) is studied with the aim of reconstructing paleoenvironmental conditions and investigating abiotic and biotic factors, including predation, that influence the paleoecology and preservation potential of spatangoid echinoids.

The echinoid fauna is dominated by the spatangoid Agassizia and, to a lesser extent, the clypeasteroid Clypeaster. The fauna also includes both regular (undetermined diadematoids and camarodonts) and irregular (Plagiobrissus, Echinocyamus, and Koehleraster) forms. Echinoids and associated fossil content, along with taphonomic and sedimentological signatures, indicate an inner sublittoral environment with moderate energy conditions affected by high-energy events. Agassizia remains, which consist mainly of complete and well-preserved tests, commonly bear subcircular drill holes that are interpreted as the result of cassid gastropod predation and investigated with respect to size selectivity and stereotypy of attack sites. Potential biases related to drilling predation and biostratinomy on the preservation potential of spatangoid tests are discussed.

Agassizia lacks any morphological adaptation to minimize high predation risk, including defensive spines and the ability to burrow deeply into the sediment. An antipredator behavior possibly relied on a gregarious life-history strategy, reducing the frequency of attacks on specific individuals by cassid predators.

A new specimen of the arachnid order Trigonotarbida is described from the Middle Pennsylvanian (lower Desmoinesian) Shelburn Formation of Indiana, which has previously yielded the remains of a phalangiotarbid. Two new trigonotarbid arachnid specimens are also described from the Middle Pennsylvanian (Desmoinesian) Senora Formation of Oklahoma. These are the first trigonotarbid specimens reported from Indiana and Oklahoma. The Indiana trigonotarbid belongs to the Eophrynidae, as indicated by distinct features such as the large tubercles on the dorsal surface of the opisthosoma and two pairs of terminal opisthosomal spines. This specimen is the first arachnid fossil to be imaged using a Multistripe Laser Triangulation scanner. The heavy dorsal tuberculation, lobed and subtriangular carapace, rounded clypeus, lack of terminal opisthosomal spines, and rounded opisthosoma on Oklahoma specimen FMNH PE 56932 indicate it belongs to the genus Aphantomartus, in Aphantomartidae. The other Oklahoma specimen, FMNH PE 56955, possesses opisthosomal tergites that are divided into five plates longitudinally as well as a subquadrate carapace, which identify it as a member of Anthracomartidae; its rounded opisthosomal margin shows it to belong to the genus Anthracomartus.

In the early Cambrian fossil record, triradial symmetry is typical for anabaritids and occurs among carinachitids. The former are an extinct group of minute benthic cnidarians covered with a calcareous tubular exoskeleton. The origin of the anabaritids is poorly understood, but previously reported triradial pyramid-shaped steinkerns and molds of the oldest conulariids, Vendoconularia, from the upper Ediacaran of the White Sea region suggested the anabaritids were closely related to conulariids. However, triradial symmetry could originate independently in different lineages in the late Ediacaran and early Cambrian. Herein we describe a new taxon, Ilankirus kessyusensis new genus new species, from the base of the Cambrian Stage 2 of the Olenek Uplift (Siberian Platform). These fossils occur as ornamented steinkerns in the shape of trilateral pyramids and lack any relics of a mineralized exoskeleton. Abundant plastic deformations and fractures of the casts suggest the organism was weakly if at all mineralized. The steinkerns are encrusted with a thin patina of iron-rich chlorite (chamosite) formed because of a multistage diagenetic replacement of authigenic glauconite (glauconite–berthierine–chamosite) under reducing conditions of oxygen-depauperate pore- and seawater. Both lacking two major autapomorphies of the crown-group conulariids (mineralized periderm and quadrate cross section of the oral region of the periderm), the late Ediacaran triradial Vendoconularia and Terreneuvian Ilankirus represent stem-group conulariids.

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Acritarch biostratigraphic and δ13C chemostratigraphic data from the Krol A Formation in the Solan area (Lesser Himalaya, northern India) are integrated to aid inter-basinal correlation of early–middle Ediacaran strata. We identified a prominent negative δ13C excursion (likely equivalent to EN2 in the lower Doushantuo Formation in the Yangtze Gorges area of South China), over a dozen species of acanthomorphs (including two new species—Cavaspina tiwariae Xiao n. sp., Dictyotidium grazhdankinii Xiao n. sp.), and numerous other microfossils from an interval in the Krol A Formation. Most microfossil taxa from the Krol A and the underlying Infra-Krol formations are also present in the Doushantuo Formation. Infra-Krol acanthomorphs support a correlation with the earliest Doushantuo biozone: the Appendisphaera grandis-Weissiella grandistella-Tianzhushania spinosa Assemblage Zone. Krol A microfossils indicate a correlation with the second or (more likely, when δ13C data are considered) the third biozone in the lower Doushantuo Formation (i.e., the Tanarium tuberosum-Schizofusa zangwenlongii or Tanarium conoideum-Cavaspina basiconica Assemblage Zone). The association of acanthomorphs with EN2 in the Krol Formation fills a critical gap in South China where chert nodules, and thus acanthomorphs, are rare in the EN2 interval. Like many other Ediacaran acanthomorphs assemblages, Krol A and Doushantuo acanthomorphs are distributed in low paleolatitudes, and they may represent a distinct paleobiogeographic province in east Gondwana. The Indian data affirm the stratigraphic significance of acanthomorphs and δ13C, clarify key issues of lower Ediacaran bio- and chemostratigraphic correlation, and strengthen the basis for the study of Ediacaran eukaryote evolution and paleobiogeography.

UUID: http://zoobank.org/5289fdb2-0e49-4b3b-880f-f5b21acab371.

Records of abnormal fossil arthropods present important insight into how extinct forms responded to traumatic damage and developmental complications. Trilobites, bearing biomineralized dorsal exoskeletons, have arguably the most well-documented record of abnormalities spanning the Cambrian through the end-Permian. As such, new records of malformed, often injured, trilobites are occasionally identified. To further expand the documentation of abnormal specimens, we describe malformed specimens of Lyriaspis sigillum Whitehouse, 1939, Zacanthoides sp. indet., Asaphiscus wheeleri Meek, 1873, Elrathia kingii (Meek, 1870), and Ogygiocarella debuchii (Brongniart, 1822) from lower Paleozoic deposits. In considering these forms, we propose that they illustrate examples of injuries, and that the majority of these injuries reflect failed predation. We also considered the origin of injuries impacting singular segments, suggesting that these could reflect predation, self-induced damage, or intraspecific interactions during soft-shelled stages. Continued examination of lower Paleozoic trilobite injuries will further the understanding of how trilobites functioned as prey and elucidate how disparate trilobite groups recovered from failed attacks.

The upper Bartonian–Priabonian shallow-marine deposits in the Biga Peninsula (NW Turkey) contain some hyaline larger benthic foraminifers (LBF) with a test architecture similar to ‘orbitoidiform’ foraminifers, but displaying some distinctive and complex morphological features that are recorded here for the first time. These coarsely porous specimens are characterized by a flat, disc-shaped, fragile, and smooth test with a layer of equatorial chambers/chamberlets, surrounded by poorly developed lateral chamberlets, never forming a discrete layer on either side of the equatorial layer. The nepionic stage is very distinctive because the bilocular embryonic apparatus is followed by a semi-rounded, notably large auxiliary chamber with a characteristic wavy outline, and consecutive cyclical chambers. The cyclical chamber arrangement is later transformed into annular cycles with numerous, complex arcuate- to cup-shaped chamberlets, as observed in equatorial sections. Bigaella orbitoidiformis Özcan, Mitchell, Pignatti, Simmons, and Yücel, n. gen. n. sp., is established for these specimens, and placed within the family Eoannulariidae Ferràndez-Cañadell and Serra-Kiel, emended herein. The new genus occurs together with Caudriella Haman and Huddleston and Epiannularia Caudri (both originally established from the American bioprovince) and the genus Linderina Schlumberger (found both in the Tethys and the American bioprovinces), together with other typical Western Tethyan LBFs. A comparison of the new genus with the aforementioned taxa is given.

UUID: http://zoobank.org/ab917e30-86d3-4bc2-8115-d17cf75f5d79.

The Upper Devonian sedimentary sequences of Central Armenia, which mainly consist of shallow water, mixed carbonate-siliciclastic deposits, contain abundant and diverse brachiopods that are dominated by spiriferides. Based on newly collected material from the lower Famennian Aramazdospirifer orbelianus brachiopod zone (coeval to the Palmatolepis crepida conodont zone) of Armenia, we here introduce two new cyrtospiriferid genera and fully document their type species, including their intraspecific variability. Pentagonospirifer n. gen. is a monospecific genus assigned to the subfamily Cyrtospiriferinae that is currently known only from the lower Famennian of Armenia; it is likely that its type species, P. abrahamyanae n. sp., evolved from the species Cyrtospirifer verneuili sensu Abrahamyan, known from the Frasnian and lower Famennian of Armenia. The second new genus, Tornatospirifer n. gen., is assigned to the subfamily Cyrtiopsinae and defined on the basis of one of the most biostratigraphically valuable cyrtospiriferid species, namely T. armenicus n. comb., described previously from the lower Famennian Aramazdospirifer orbelianus Zone of Armenia. It is likely that it evolved from a Frasnian ancestral stock of Tiocyrspis Sartenaer, known from northwestern Europe, which probably migrated during the early Frasnian to the north Gondwanan margin. A neotype is selected for Abrahamyan's species because the type material is lost. Epibionts (Cornulites, Hederella) attached to brachiopods are also documented for the first time from the Upper Devonian of Armenia.

UUID: http://zoobank.org/923d232f-cd6a-48bb-8a05-27c689058b65.

Parioxys ferricolus Cope, 1878 is a long-neglected taxon of dissorophid temnospondyls from the early Permian (Cisuralian) of Texas. Reexamination of the original material and preparation of a previously undescribed specimen shed some light on the ontogeny and reveal numerous eucacopine features. P. ferricolus is characterized by: (1) a preorbital region 1.5 times as long as the posterior skull table in juveniles and twice as long in adults, (2) a parietal only two-thirds the length of the frontal, (3) interpterygoid vacuities shorter than half the skull length, (4) choanae posteriorly extended, and (5) vomer with enlarged, V-shaped median depression. P. ferricolus is found nested with Kamacops acervalis Gubin, 1980, with which it shares synapomorphies in the palate, within the dissorophid clade Eucacopinae.

Ordovician open marine Lagerstätten are relatively rare and widely dispersed, producing a patchy picture of the diversity and biogeography of nonmineralized marine organisms and challenging our understanding of the fate of Cambrian groups. Here, for the first time, we report soft-bodied fossils, including a well-preserved marrellomorph arthropod, fragmentary carapaces, and macroalgae, from the Late Ordovician (Katian) Upper Member of the Kirkfield Formation near Brechin, Ontario. The unmineralized elements and associated exceptionally preserved shelly biota were entombed rapidly in storm deposits that smothered the shallow, carbonate-dominated shelf. The marrellomorph, Tomlinsonus dimitrii n. gen. n. sp., is remarkable for its ornate, curving cephalic spines and pair of hypertrophied appendages, suggesting a slow-moving, benthic lifestyle. Reevaluation of marrellomorph phylogeny using new data favors an arachnomorph affinity, although internal relationships are robust to differing outgroup selection. Clades Marrellida and Acercostraca are recovered, but the monophyly of Marrellomorpha is uncertain. The new taxon is recovered as sister to the Devonian Mimetaster and, as the second-youngest known marrellid, bridges an important gap in the evolution of this clade. More generally, the Brechin biota represents a rare window into Ordovician open marine shelf environments in Laurentia, representing an important point of comparison with contemporaneous Lagerstätten from other paleocontinents, with great potential for further discoveries.

UUID: http://zoobank.org/884589d0-08f7-4398-ab42-1f5d459be9e9

Silty noduliferous shales in the lower part of the Middle Ordovician (late Darriwilian 2) Taddrist Formation in the central Moroccan Anti-Atlas contain a unique assemblage of conulariids consisting of one species each of Archaeoconularia Bouček, 1939, Glyptoconularia Sinclair, 1952, and Pseudoconularia Bouček, 1939. Glyptoconularia antiatlasica new species, currently represented by a single three-dimensional specimen, is the first member of this extremely rare, highly autapomorphic genus to be described from outside of cratonic North America as well as the first Glyptoconularia from the Middle Ordovician. Pseudoconularia cf. P. grandissima (Barrande, 1867) and Archaeoconularia cf. A. exquisita (Barrande, 1867) most closely resemble species previously described from Middle and Upper Ordovician strata in the Prague Basin (Czech Republic), then located adjacent to North Africa. Anaconularia anomala (Barrande, 1867), previously known from the Upper Ordovician (Sandbian) Libeň and Letná formations in the Prague Basin, is documented for the first time from the Upper Ordovician (Katian) Upper Tioririne Formation of Morocco. In addition to extending the known stratigraphical and paleogeographical ranges of these conulariids, results of the present investigation add to the list of invertebrate taxa that appear to have originated during Early or Mid-Ordovician times in peri-Gondwana or south-polar Gondwana, and then migrated to the eastern margin of Laurentia, arriving there along with other cool-water taxa during the Sandbian-Katian transition.

UUID: http://zoobank.org/9ea5051b-cff5-4911-861a-531db4f45883

Ohiocrinus byeongseoni n. sp. from the Middle Ordovician (Darriwilian) Jigunsan Formation of South Korea in the Sino-Korean (North China) block is the oldest species of Ohiocrinus of the Cincinnaticrinidae and the first record outside Laurentia. O. byeongseoni is characterized by a loosely clockwise-coiled anal sac, isotomous branching throughout arms, long, slender xenomorphic column, and small lichenocrinid-type holdfast. The new species occurs in association with a deep-water siliciclastic environment, unlike the Laurentian species with a shallow-water carbonate environment. The monospecific crinoid assemblage is interpreted as parautochthonous, considering that the crinoids were reworked by relatively weak down-current probably caused by storm but preserved within the environment where they lived. The occurrence of O. byeongseoni presents a considerable spatiotemporal gap and ecologic disparity in evolution of Ohiocrinus and the Cincinnaticrinidae.

UUID: http://zoobank.org/240417a4-8d33-4f45-aedb-afcc07f1ecbb

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 enantiornithine, Musivavis amabilis n. gen. n. sp., is reported from the Lower Cretaceous Jehol Biota in western Liaoning, China. The new taxon is similar to the bohaiornithids in the robust subconical teeth, bluntly expanded omal ends of the furcula, caudolaterally oriented lateral trabeculae with triangular distal ends of the sternum, and a robust second pedal digit. Yet it differs from members of Bohaiornithidae in several features recalling other enantiornithine lineages, such as the acuminate rostral ramus of maxilla, the shape of the coracoid lateral margin, the presence of craniolateral processes on the sternum, the proportions of the manual phalanges, and the unspecialized third pedal ungual phalanx. A comprehensive phylogenetic analysis of Mesozoic birds shows that homoplasy significantly affects the reconstruction of enantiornithine relationships. When all phylogenetic characters are considered of equal weight, Musivavis is reconstructed in a lineage related to a radiation of large-bodied enantiornithines including Bohaiornithidae and Pengornithidae. Alternative scenarios based on progressive downweighting of the homoplastic characters support more basal placements of the pengornithids among Enantiornithes, but do not alter the affinity of Musivavis as a member of the “bohaiornithid-grade” group.

UUID: http://zoobank.org/617c7062-21ab-4d33-ae80-4edf5a129683

Based on extensive new material, 2088 valves resulting from search sampling of ~500 kg of sediment, the Pliocene chiton biodiversity of the Mondego Basin (Portugal) is reassessed. Twelve species were identified, assigned to seven genera. Eight species are new for the Pliocene of Portugal, as well as two of the genera: Hanleya, Acanthochitona. Two taxa are described as new: Ischnochiton loureiroi n. sp. and Lepidochitona rochae n. sp. Until now, the polyplacophoran European Neogene record was too poorly known to be of help in generating a clear picture of the Miocene to present-day biogeography of the group. This new wealth of data from western Iberia, in conjunction with recent data from the Loire Basin Upper Miocene assemblages (France), allows clarification the Late Miocene to Recent eastern Atlantic and Mediterranean biogeography of the Polyplacophora. The northern range of warm-water northeast Atlantic and Mediterranean Polyplacophora experienced a sharp contraction since, at least, Late Miocene to Early Pliocene times. Warm-water chiton species represented in the Upper Miocene of the Loire Basin of NE France (European-West African Province) and the Pliocene of the Mondego Basin of central-west Portugal (Pliocene French-Iberian Province) are today confined to the southern Mediterranean-Moroccan Molluscan Province.

UUID: http://zoobank.org/a2a550c0-caed-449a-aa45-9492c45f882e

The fossil record of octocorals from Cenozoic marine strata of western North America is quite limited, and they have not been reported previously from rocks in Washington State, USA. Two late Oligocene specimens from the upper part of the Lincoln Creek Formation in western Washington, referred to Radicipes? sp., are the first fossil record of the family Chrysogorgiidae. The family Isididae is represented by an internode and two holdfasts identified as Isidella sp. collected from the Oligocene Pysht Formation, along with specimens questionably identified as Lepidisis sp., possibly the first fossil record for this genus. Together, these are the first confirmed fossils of the Alcyonacea from north of California in western North America. The axes of sea pens from several late Eocene or early Oligocene localities in the Lincoln Creek Formation in the central part of western Washington, and the Pysht and Makah formations on the north side of the Olympic Peninsula, are the first fossil record for the Pennatulacea from western North America; all are tentatively referred to the genus ‘Graphularia’. Large axes from the Lincoln Creek Formation and Makah Formation are referred to ‘Graphularia’ (?) aff. sasai, because they are similar to the species known only from late Eocene and early Oligocene rocks in Japan.