Modern Nautilus, in natural and laboratory settings, scavenges both dead and molted decapod crustaceans. Ingestion of palinurid lobster exuviae by Nautilus follows a specific pattern in which the cephalopod consumes the exoskeleton beginning at the posteriormost part of the abdomen and continuing anteriorly. During the ingestion process, the cephalothorax is least likely to be consumed, either because the Nautilus may abandon the remains, or the cephalothorax may become separated from the abdomen at its weakest point, the articulation of the cephalothorax with the abdomen. Examination of 767 fossil lobster specimens from 50 formations, 41 of Cretaceous age, demonstrates that the fossil record of lobsters, the preponderance of which appear to be exuviae, is strongly biased in favor of cephalothoraxes. Observations on Nautilus suggest that anatomically selective scavenging by ancient cephalopods, both nautiloids and ammonoids, may explain, in part, the selective preservation of lobster cephalothoraxes over abdomens. Despite the range of variation in jaw morphologies among ammonoids, probably most could have fragmented and ingested decapod remains. Evidence for selective scavenging in the geologic past is purely circumstantial; no cephalopod bitemarks have been identified on fossil lobster exuviae. Pre-burial decomposition of connective tissues and subsequent disarticulation of the abdomen in the absence of scavenging may also have contributed significantly to the observed anatomical taphonomic bias.

A large number of conifer pollen cones associated with primitive walchian conifers, including Emporia, occur within an exceptionally preserved fossilized biota near Hamilton, Kansas, USA. The fossils are derived from channel deposits within the Upper Pennsylvanian (Stephanian B/C) Topeka Limestone and show excellent external morphology, internal anatomy, and cuticular features. Pollen cones are cylindrical, up to 5 cm long and 1 cm wide and are simply organized. Each pollen cone consists of a nonwoody central axis from which sporophylls diverge in a helical arrangement. Vascular tissue comprises a ring of tiny cauline bundles that divide at intervals to produce a single trace to each sporophyll. Sporophylls consist of a terete stalk and a heeled distal lamina. Sporangia are attached as a cluster on the adaxial surface of the sporophyll stalk. Stomata occur in one or two bands on the inner surface of sporophyll laminae and consist of guard cells surrounded by a ring of subsidiary cells, each with one overarching papilla. The Hamilton specimens provide conclusive evidence that pollen cones with a distinctive morphology were produced by some of the most ancient walchians from both North America and Europe. Contrary to traditional interpretations, these cones differ significantly from those of the Pinaceae. The broad geographic and stratigraphic distribution of this morphology reveals that conifer pollen cones similar to those at Hamilton are more widespread than previously suspected, and provides evidence for the potentially ancestral morphology of all conifer pollen cones.

Representatives of several genera of late Paleozoic Caenogastropoda have been studied based on exceptionally well-preserved material from the latest Permian of south China, the Pennsylvanian of the United States, and the Early Carboniferous of Australia. This material has well-preserved protoconchs which are relatively rare in Paleozoic gastropods. The morphology of the protoconch and especially that of planktotrophic larval shells gives crucial taxonomic and phylogenetic information. It helps to recognize convergence, which is common in Gastropoda. The larval shell morphology of the following taxa is discussed and illustrated: Platyzona (Goniasmatidae), Erwinispira n. gen. (Erwinispirinae n. subfam.), Propupaspira (Propupaspiridae), Soleniscus (Soleniscidae), Meekospiridae, and Chlorozyga (Imoglobidae). The new species Meekospira? solenisiciforma is described. The main diagnostic feature of the order Procaenogastropoda, a fluent protoconch/teleoconch transition, probably represents a preservational artifact. An abrupt transition indicating metamorphosis can be shown for several genera which have been assigned to the Procaenogastropoda. Therefore, the monophyly of the Procaenogastropoda is questioned, and the taxon is refuted. While the caenogastropods of latest Permian gastropod faunas are dominated by typical late Paleozoic genera and families, the Early Triassic is characterized by an almost complete faunal turnover of caenogastropod genera.

The first Mesozoic thylacocephalans from the western hemisphere are documented from the Muhi Quarry plattenkalk in the La Negra facies of the El Doctor Formation (Albian–Cenomanian), Zimapán Area, northwestern Hidalgo, central Mexico. They all are found in a single horizon at the base of the type section. These specimens represent two new genera and species, and a third undetermined species which likely also represents a new genus and species. Victoriacaris muhiensis is a shorted-bodied thylacocephalan with concave anterior and posterior notches as well as a beveled anterior spine. Polzia eldoctorensis is trapezoidal in outline with a rounded posteroventral corner. The third undetermined species is known only from one broken specimen, but has distinctive marginal spines that are not possessed by any other post-Cambrian thylacocephalan. The occurrence of such a diverse fauna of thylacocephalans markedly increases the diversity and geographic range of Cretaceous thylacocephalans, but does not offer any insights into the tempo of thylacocephalan extinction at the end of the Cretaceous.

Numerous Early Cambrian corals or “coralomorphs,” as they are often classified, are recorded from North America, Australia, and Siberia. A new Early Cambrian coral, Harklessia yuenglingensis n. gen. and sp., is found in conjunction with archaeocyathan-microbial reefs in Esmeralda County, southwestern Nevada. The coral-bearing reefs are within quartzic, trilobite-rich packstone beds in the upper portion of the Harkless Formation (Bonnia–Olenellus Zone). Coralla are constructed by subpolygonal to polygonal, cerioid, close-packed corallite tubes. Coralla average 12 cm in height by 18 cm in diameter with individual corallite tubes ranging from 1.2 to 3.2 mm in diameter. Corallites are greater than 25 mm in length. Septa and tabulae are not present.

Many of the Early Cambrian corals previously described have attributes of the class Anthozoa and subclass Zoantharia, with some specific similarities to tabulate corals. Harklessia yuenglingensis is placed confidently within the class Anthozoa, subclass Zoantharia because its morphological characteristics indicate an affinity to true corals, but whether H. yuenglingensis is a tabulate coral remains uncertain.

The tooth enamel of the earliest cetacean, Pakicetus, is described and compared to enamel of a primitive artiodactyl and a variety of primitive ungulate families. Pakicetus enamel organization, which is considered primitive for Cetacea, consists of a combination of radial and decussating enamel types. Prism patterns include prisms with open (horseshoe-shaped) and closed (circular) boundaries. Pakicetus enamel is similar to that of many primitive ungulates, including Diacodexis, the earliest artiodactyl, and Mesonychidae, an archaic ungulate family that often is considered close to the ancestry of Cetacea. This finding is consistent with the hypothesis, originally proposed on the basis of other aspects of morphology, that artiodactyls, cetaceans, and Mesonychidae are closely related.

The marine Triassic rocks of Nevada are well known for their ichthyosaur finds, and a number of new genera and species were described from this state. Based on a few vertebrae, Leidy (1868) erected a new Middle Triassic ichthyosaur genus, Cymbospondylys, with two species, C. petrinus and C. piscosus. The type material of C. petrinus came from the Prida Formation of the southern Humboldt Range, and that of C. piscosus from the Favret Formation of the New Pass Range.

The first two rove beetle fossils discovered from the Late Jurassic Talbragar Fish Bed in New South Wales, Australia are described and illustrated. Juroglypholoma talbragarense n. sp. is the second fossil record for one of the smallest and latest recognized staphylinid subfamily Glypholomatinae. The other staphylinid, Protachinus minor n. gen. n. sp., is an unusual member of extant subfamily Tachyporinae (tribe Tachyporini). It significantly retains several distinct features, including entire epistomal suture, and abdominal tergites III–VI each with a pair of basolateral ridges. The discovery of a new glypholomatine in Australia, together with recently reported one from the Middle Jurassic Daohugou biota of China, suggests the subfamily Glypholomatinae was probably much more widespread in the Jurassic than previously thought.

The Hungry Hollow Formation on the southeastern margin of the Michigan Basin is interpreted as a composite stratigraphic unit representing the lateral equivalents of two depositional cycles in the northern Appalachian Basin. The basal beds (? = Pompey and upper Levanna transgressive hemicycle of the upper Skaneateles Formation in New York) are separated by disconformity surfaces both from the underlying Arkona Shale and from the upper part of the Hungry Hollow (= upper part of Centerfield Limestone Member). These basal beds were deposited on eroded, overcompacted claystones of the Arkona Shale, contain a diverse suite of remanie sediments, and fill deep, delicately sculpted furrows of Cruziana transversa n. ichnosp., C. reticulata n. ichnosp., and Rusophycus bilobatum (Vanuxem, 1842). This lower disconformity may be recognizable regionally over the Northern Midcontinent. Overlying beds feature the lowest local occurrence of an offshore-aspect conodont fauna of the lower Polygnathus varcus Subzone. The underlying Arkona Shale yields Icriodus-dominated (nearer-shore aspect) faunas apparently representing Polygnathus xylus ensensis Zone assemblages. The upper part of the Hungry Hollow Formation and overlying lower part of the Widder Formation represent an offlap-onlap cycle within the lower Polygnathus varcus Subzone that is comparable to that of the upper part of the Centerfield Limestone.

Cruziana and Rusophycus from the Hungry Hollow were not originally produced as “under-tracks” but were formed at the sediment–water interface on erosion-resistant, overconsolidated muds. The producer of Cruziana reticulata n. ichnosp. appeared in the benthic community of the field area before the excavator of C. transversa n. ichnosp. and of Rusophycus bilobatum (possibly the trilobite Dipleura). The degree of limb swing required to produce the reticulate scratch patterns in C. reticulata n. ichnosp. suggests the evolution of specialized coxa-sternite and inter-podomere hinges that were not previously considered to be present in trilobites. Comparable reticulate scratch patterns occur as early as the earliest Cambrian and are apparently related to excavation on disconformity-related mud firmgrounds.

This study presents the first record of Eocene birds from the western margin of southernmost South America. Three localities in Magallanes, southern Chile, have yielded a total of eleven bird remains, including Sphenisciformes (penguins) and one record tentatively assigned to cf. Ardeidae (egrets). Two different groups of penguins have been recognized from these localities. The first group is similar in size to the smallest taxa previously described from Seymour Island, Marambiornis Myrcha et al., 2002, Mesetaornis Myrcha et al., 2002, and Delphinornis Wiman, 1905. The second recognized group is similar in size to the biggest taxa from Seymour Island; based on the available remains, we recognize the genus Palaeeudyptes Huxley, 1859, one of the most widespread penguin genera in the Southern Hemisphere during the Eocene. The stratigraphic context of the localities indicates a certain level of correlation with the geological units described on Seymour Island. The newly studied materials cast more light on the paleobiogeography of the group, extending the known ranges to the South American continent. In addition to the newly discovered birds, the presence of several taxa of elasmobranchs previously recovered exclusively from Eocene beds in the Southern Hemisphere help to clarify the age of the studied localities, widely discussed during the last decades. This paper verifies the presence of extensive Eocene sedimentary successions with fossil vertebrates along the western margin of southern South America, contrary to the previous assumption that such a record is lacking in Chile.

New data on the proximal structure of several glossograptid species, including Paraglossograptus holmi, indicate that symmetry between sicula and the first theca is ubiquitous and primitive for the group. This isograptid symmetry is shared with species of Isograptus and Oncograptus, among others, as is a dicalycal second theca, and the initial downward growth of the first several thecal pairs. Consideration of these and other features of the rhabdosome structure leads us to reassess the phylogenetic relations among Glossograptus, Pseudisograptus, Isograptus, and their relatives. The Glossograptidae is a holophyletic clade comprising the common ancestor of Isograptus caduceus and I. victoriae and all its descendants, including the monopleural glossograptines. Incipient monopleural development is exhibited by the otherwise Isograptus-like Bergstroemograptus crawfordi. Derived glossograptids, such as Glossograptus and Kalpinograptus, share a fully monopleural rhabdosome with a prominent proximal bulge formed by the overlap of the early thecae. Contrary to some claims, none possesses a manubrium or manubrium-like structure. The manubrium and the arienigraptid suture are restricted to Arienigraptus hastatus and its descendants. These features unite the Arienigraptidae. The Arienigraptidae, based on their possession of isograptid symmetry and lack of any derived characters shared uniquely with the glossograptids, appear to be a sister group of the Glossograptidae rather than a stem group. These two families appear most closely allied to certain reclined, two-stiped species, such as Isograptus? dilemma, that retain tetragraptid proximal symmetry.

Lower and Middle Devonian brachiopod-dominated communities of Nevada are numerous (46) and most are positioned on or adjacent to the carbonate-platform foreslope or ramp. Level-bottom community chains are fundamentally different from community associations that are interrupted by a platform margin. All communities require relative abundance data of constituent species for recognition. These communities prove to be endemic to the Nevada-southeastern California area, even though faunal similarities with distant regions in North America can be recognized. Analogous communities, the same age as comparable communities in Nevada, differ in overall specific content and in relative abundance of diagnostic species. Identification of analogous communities requires recognition of common physical environments (first) and faunal similarity (second). Groupings of communities based on presence-absence data of key species and genera are not meaningful.

Biofacies boundaries sited on carbonate-platform foreslopes separate community associations and also act as filter boundaries for faunal realms. The platform and peripheral biofacies thus delineated are also realms, a pattern that is repeated by different organisms from Cambrian to Cenozoic. Biofacies boundaries shift in concert with large-scale sea-level fluctuations. During platform emergence, most faunas are peripheral and therefore cosmopolitan. Transgression initially forms small, isolated epeiric seas populated from offshore, and endemic faunas evolve. Increased transgression merges epeiric seas and faunas, reducing provinciality and diversity through competition. Regression results in extinctions in proportion to its rate and the area involved. The cycle repeats.

The hermanni-cristatus conodont Zone is replaced with the name hermanni Zone. The disparilis Zone is divided into Lower and Upper Subzones. The norrisi Zone is proposed at the top of the Middle Devonian.

Species of the late Osagean and early Meramecian primitive cladid crinoid genera Atelestocrinus, Barycrinus, Cestocrinus, Costalocrinus, Cyathocrinites, Meniscocrinus n. gen., Parisocrinus, Pellecrinus, and Saccosomopsis from Illinois, Indiana, Iowa, Kentucky, Missouri, and Tennessee are reviewed, redescribed, and redefined from study of type material, museum collections, and field collections. Nomenclatural and systematic acts include the following: 1) Barycrinus spurius (Hall, 1858) is a senior synonym of Cyathocrinus tumidus Hall, 1858, C. protuberans Hall, 1858, and B. mammatus Meek and Worthen, 1873; 2) B. rhombiferus (Owen and Shumard, 1852a) is a senior synonym of C. sculptilis Hall, 1860, C. thomae Hall, 1860, C. hoveyi Hall, 1861a, C. wachsmuthi Meek and Worthen, 1861, B. herculeus Meek and Worthen, 1868, B. pentagonus Meek and Worthen, 1873, B. striatus Worthen, 1875, B. boonvillensis Miller, 1891b, B. formosus Miller and Gurley, 1894, B. washingtonensis Miller and Gurley, 1895, and B. elrodi Miller and Gurley, 1896a; 3) B. magister (Hall, 1858) is a senior synonym of C. solidus Hall, 1861a and B. magnificus Meek and Worthen, 1868; 4) B. stellatus (Hall, 1858) is a senior synonym of C. bullatus Hall, 1858, C. angulatus Meek and Worthen, 1860, C. quinquelobus Meek and Worthen, 1865, and B. astericus Van Sant, 1964; 5) B. crassibrachiatus (Hall, 1860) is a senior synonym of B. princeps Miller and Gurley, 1890a; 6) B. geometricus Meek and Worthen, 1873, is considered a nomen dubium; 7) B. benedicti (Miller, 1891a) is considered a nomen dubium; 8) Cyathocrinus signatus Miller and Gurley, 1894, is assigned to Cestocrinus and is a senior synonym of Cestocrinus striatus Kirk, 1940; 9) Cyathocrinites iowensis (Owen and Shumard, 1850) is a senior synonym of C. malvaceus Hall, 1858, C. divaricatus Hall, 1858, C. rotundatus Hall, 1858, C. viminalis Hall, 1861a, C. parvibrachiatus Hall, 1861a, C. hamiltonensis Worthen, 1882, C. nodosus Wachsmuth and Springer, 1890, C. brevisacculus Wachsmuth and Springer, 1890, C. opimus Miller and Gurley, 1890a, and C. gurleyi Miller, 1891a; 10) C. kelloggi (White, 1862) is a senior synonym of C. subtumidus Meek and Worthen, 1865; 11) C. farleyi (Meek and Worthen, 1866b) is a senior synonym of C. andersoni Miller and Gurley, 1894, C. granulosus Rowley, 1902, and C. snivelyi Rowley, 1902; 12) C. harrodi (Wachsmuth and Springer, 1880) is a senior synonym of C. boonvillensis Miller, 1891b, C. gorbyi Miller, 1892b, and C. astralus Kammer, 1984; 13) Meniscocrinus n. gen. is described and M. magnitubus n. sp. is assigned to this new genus; 14) C. labyrinthicus Miller, 1891a, is assigned to Parisocrinus; 15) C. intermedius Hall, 1858, is assigned to Pellecrinus; and 16) C. insperatus Lyon, 1869, is assigned to Saccosomopsis and is a senior synonym of C.? poterium Meek and Worthen, 1870.

A nearly complete and well-preserved skeleton of the Columbian mammoth (Mammuthus columbi) and a cranial fragment of a short-faced bear (Arctodus simus) were recovered from fossil lake deposits at 2,740 m, near the crest of the Wasatch Plateau, central Utah. The mammoth bones are reliably dated to between 11,500 and 9,500 yr B.P. and may be associated with a late Paleoindian occupation at the site. The mammoth and bear are part of a high elevation Huntington Canyon megafauna including mastodon (Mammut americanum), horse (Equus sp.), and bison (Bison sp.). The mammoth was an old bull with considerable pathology in the vertebral column, ribs, and legs. Pollen, plant macrofossils, insects, and dung associated with the mammoth suggest this megafauna occupied an essentially modern environmental setting after deglaciation of the Wasatch plateau.

Eospirifer praecursor n. sp. is the oldest known eospiriferine, probably ancestral to the entire Spirifer group. It is described here based on external and internal mold material from the uppermost part of the Changwu Formation (mid-Ashgill, Late Ordovician), Hejiashan, Jiangshan, western Zhejiang, East China. A study of the ontogeny of E. praecursor n. sp. suggests that the cardinalia of early growth stages are more similar to those of early atrypoids rather than to those of the orthoids but the brachidia in these earliest Eospirifer are still unknown. The possibility that eospiriferines were derived from an atrypoid stock cannot be excluded. All early eospiriferine species recorded from the Ashgill, Rhuddanian, and early Aeronian are reviewed for comparison. Their morphological diversification reveals early evolutionary experimentation. Based on the Ashgill occurrence of Eospirifer, it is likely that East Asia may be considered as one of the eospiriferine source areas.

Peritidal cherts and silicified phosphorites of the Early Cambrian Kyrshabakta (Berkuta Member) and Chulaktau formations of South Kazakhstan contain diverse assemblages of cellularly permineralized microorganisms that like other microbiotas of similar age and setting are dominated by cyanobacteria, both filamentous (oscillatoriacean trichomes and empty sheaths) and coccoidal (chroococcaceans). Although these near-shore assemblages contain sphaeromorph acritarchs, they differ from Neoproterozoic and Early Cambrian microbiotas of more open-marine environments by lacking morphologically complex planktonic eukaryotes such as the acanthomorphic acritarchs that are abundant in the Chulaktau-overlying Shabakta Formation. In general composition, the Berkuta and Chulaktau assemblages are similar both to microfossil assemblages of the pre-trilobite Rovno and Lontova Regional Stages of the East European Platform and to Early Cambrian microbiotas known from chert-phosphorite deposits worldwide.

The studies reported here are based on use of optical microscopy combined with techniques recently introduced to paleobiology: confocal laser scanning microscopy, and Raman and fluorescence spectroscopy and imagery. Taken together, these provide information in situ, in three dimensions and at high spatial resolution, about the organismal morphology; cellular anatomy; chemical composition; and mode, fidelity, and environment of preservation of the permineralized microfossils. Data are presented suggesting that the substitution of samarium for calcium in fossil-preserving apatite may provide evidence of its oxic or anoxic paleoenvironment of formation.

We interpret the Berkuta and Chulaktau assemblages to be composed of 27 taxa assigned to 17 genera of microscopic prokaryotes and eukaryotes that include one new genus and species, Berkutaphycus elongatus.

A new species, Enchodus brevis (Enchodontoidei: Enchodontidae), is described from lower Cenomanian beds in Ein-Yabrud, near Jerusalem. The species is characterized by the following features: the shortest enchodontid body; an ectopterygoid bearing one smooth canine terminal tooth; barbed dentary teeth; a huge front tooth of dentary with two anterior cutting edges; two supraneurals; second preural vertebra without a neural spine; and absence of lateral line scales except for a long hook-like terminal scale at the caudal peduncle. The systematic position of the new species suggests the emendment of the generic diagnosis.

New and more-complete material of Procolpochelys charlestonensis Weems and Sanders, 2014 provides the first detailed information on the skull, jaw, and plastron of this species, which occurs in the Oligocene Ashley and Chandler Bridge formations near Charleston, South Carolina. This material allows a much more detailed comparison of this turtle with the co-occurring pancheloniid species Ashleychelys palmeri Weems and Sanders, 2014 and Carolinochelys wilsoni Hay, 1923a, as well as with its Miocene successor Procolpochelys grandaeva (Leidy, 1851). Fused dentaries, found in the Cooper River north of Charleston, belong to the pancheloniid genus Euclastes, previously known only from the Upper Cretaceous and Paleocene. This specimen, apparently from the upper Eocene Parkers Ferry Formation, expands the temporal range of this genus and indicates that Euclastes survived in the North Atlantic basin far longer than was previously known. These new finds, combined with previous records of fossil pancheloniid sea turtles, provide an improved picture of the temporal distribution, evolutionary trends, and likely phylogeny of pancheloniids from the Late Cretaceous to the present.

Borings and bite marks on fossil turtle carapaces and plastra from the Miocene Moghra Formation, northern Egypt, are herein described. All fossil turtle material from Moghra exhibits ichnofossils. The positions of invertebrate borings on external surfaces of tortoise and turtle shell material at Moghra are consistent with the activities of ectoparasites or mesoparasites.

A single invertebrate ichnotaxon, Karethraichnus lakkos Zonneveld et al., 2016, occurs on Moghra tortoise fossils. This trace fossil was likely emplaced by ixodid arthropods (ticks). Bite marks assigned to Nihilichnus occur on a carapace peripheral and are interpreted to reflect postmortem scavenging. An abundant and moderately diverse assemblage of invertebrate borings characterizes Moghra aquatic turtle shells. Karethraichnus lakkos and Thatchtelithichnus holmani Zonneveld et al., 2016 traces on aquatic turtles are interpreted to reflect leech and/or trematode parasitism. Gunnellichnus moghraensis (new ichnogenus new ichnospecies) and G. akolouthiste (n. isp.) likely reflect bacterial and/or fungal infections on aquatic turtle shells that rarely dried out.

UUID: http://zoobank.org/f0a3977d-deff-4954-b196-536adc405854

The present work presents a detailed taxonomic study on Ostracoda from the Quiricó Formation, Areado Group, São Francisco Basin, Brazil. The samples were collected from three outcrops in the Minas Gerais State: Tereza Farm (João Pinheiro Municipality), and from the banks of the São José and Quiricó creeks (Presidente Olegário Municipality). Sixteen ostracode species were recovered: Harbinia alta, Harbinia aff. H. angulata, Harbinia aff. H. crepata, Harbinia aff. H. salitrensis, Harbinia symmetrica, Brasacypris fulfaroi, Brasacypris ovum, Cypridea conjugata, Cypridea hystrix, Cypridea infima, Cypridea jequiensis, Neuquenocypris (Protoneuquenocypris) antiqua, Penthesilenula martinsi, Penthesilenula pintoi new species, Alicenula longiformis new species, and Timiriasevia sanfranciscanensis new species. With the recovery of well-preserved specimens, it was possible to observe new characteristics in Brasacypris ovum, Cypridea conjugata, C. hystrix, and C. infima, and propose emendments to them. Additionally, three new species are described: Penthesilenula pintoi n. sp., Alicenula longiformis, n. sp., and Timiriasevia sanfranciscanensis n. sp. To date, the genus Timiriasevia had not been recorded in strata from Brazil. Also, Darwinula martinsi is reassigned to the genus Penthesilenula. Several species herein recorded are also found in other Brazilian continental basins, as well as in African and Argentinian basins, contributing to the knowledge of Brazilian Cretaceous continental deposits.