We establish a new genus of a hyaenaelurine hyaenodontid (Creodonta: Mammalia), Orienspterodon for “Pterodon” dahkoensis, which is known from three late middle Eocene localities in central and southern China and Myanmar. This paper provides a full description of the species and a comment on the early evolution of Hyaenaelurinae. Some features of Orienspterodon (p2–p3 without an anterior accessory cuspulid, lesser reduction of the m3 talonid relative to m1–m2 talonids, double-rooted P3, and better fusion of the paracone and metacone on M1) confirm that O. dahkoensis is distinct from Pterodon. Orienspterodon differs from the other specialized hyaenodontids from the Paleogene of Asia in being a hyaenaelurine, in being unrelated to Hyaenodon, and in having a geographical distribution in the southern part of the continent. Orienspterodon represents the earliest fossil records of Hyaenaelurinae, and some features (small metaconid on m3, basined talonid on all lower molars, a short and more diagonally oriented metastyle, large size, better fused paracone and metacone) indicate an early branching of this genus from the other hyaenaelurines.

Calcareous articulate brachiopods are rare components of the high diversity, phosphatic, silicified, and epidote coated shelly fauna derived from Middle Cambrian (Floran-Undillan) allochthonous limestone clasts from the Murrawong Creek Formation, southern New England Fold Belt, northeastern New South Wales, Australia. Three taxa are described, the kutorginids Nisusia metula n. sp., and Yorkia sp. indet., and the protorthid Arctohedra austrina n. sp. Yorkia is documented from Australia for the first time. An unusual valve (possibly a brachial valve) of enigmatic affinity is also reported and illustrated. Generically, the taxa provide broad regional paleobiogeographic links with the “first discovery limestone” Member of the Coonigan Formation, western New South Wales, and the Current Bush Limestone in the Georgina Basin, northern Australia, and globally, with broadly contemporaneous sequences in western North America, Siberia, and South China.

A costal and a peripheral bone from the Early Cretaceous (Valanginian, ca. 135 Ma) Rosablanca Formation, Zapatoca town, Colombia are described. These specimens represent the earliest record of podocnemidoid turtles. Evolutionary and paleogeographical implications are also discussed.

A partial skeleton of a pelagornithid bird found in latest Oligocene or earliest Miocene marine strata in Oregon consists of a pelvis fragment, thoracic vertebrae, and leg bones of a single individual. It is the most completely preserved pelagornithid from the late Oligocene/early Miocene, and one of the few bony-toothed birds from this time period in general. The new fossil is from the Nye Mudstone and shows some previously unknown features that contribute to a better understanding of the osteology of pelagornithids. Because Paleogene and late Neogene pelagornithids differ in several osteological features and the temporally intermediate forms are poorly known, it further bridges a gap in our knowledge of character evolution in pelagornithids. The interrelationships within Pelagornithidae are still poorly resolved, but we detail that a clade of Neogene species, which the Oregon pelagornithid is not part of, can be supported by a derived morphology of the femur. To ease description of Neogene pelagornithids, we synonymize Palaeochenoides Shufeldt, 1916 and Tympanonesiotes Hopson, 1964 with Pelagornis Lartet, 1857, and suggest classification of all Neogene pelagornithids in the latter taxon.

The first records of the upper Cambrian agnostoid genera Kormagnostella, E. Romanenko, in Romanenko and Romanenko, 1967, and Biciragnostus F. Ergaliev, in Eraliev and Ergaliev, 2001, in Laurentian North America are from a narrow stratigraphic interval in the Steptoean–Sunwaptan boundary interval (Furongian, Jiangshanian) of Nevada and Utah. In Nevada, both genera occur in a condensed bioclastic lag below a major flooding surface, and Kormagnostella also appears in a transgressive interval in Utah. Immigration of these genera is associated with sea level rise, and also with faunal turnover. Biciragnostus is confined to the latest Elvinia Zone, immediately below the onset of a trilobite and agnostoid extinction event at the base of the Irvingella major Zone (basal Sunwaptan). Kormagnostella is present in the latest Elvinia Zone, and has its highest occurrence in the I. major Zone. Stratigraphic data from the Karatau-Naryn Terrane, Kazakhstan indicate that both genera disappear near the local extinction of Irvingella, suggesting that faunal turnover in that region may have been broadly correlative with the more profound extinction in Laurentia. New species are Kormagnostella advena, K. insolita and Biciragnostus viator.

Examination of 186 specimens of the living brachiopod Laqueus rubellus (Sowerby), collected during four different months from Sagami Bay, Japan, has yielded 94 specimens of the pinnotherid crab, Pinnotheres laquei Sakai, living within the mantle cavity. This work provides the first quantitative statements regarding crab/brachiopod associations. All but four of the specimens were female crabs; the four male specimens occurred together with females in brachiopods collected during March, 1982. Pinnotherids, common associates of mollusks and echinoderms, tend to be host specific; however, anecdotal information received near the conclusion of this study suggests that P. laquei may visit multiple brachiopod host species. Although the crabs seem to be more common in larger brachiopods, there is some correspondence between crab size and brachiopod size. No physical evidence, such as malformation of the shell or lophophore loop, was observed in host brachiopods and, therefore, the association was judged to be commensal or symbiotic. It is probable that crabs were able to enter and exit the mantle cavity at will. This association of brachiopod and pinnotherid represents the only known occurrence of infestation of brachiopods by crabs and, with the exception of boring and encrusting organisms, is one of very few biotic associations, of any kind, for brachiopods. Although this association has not yet been reported from the fossil record, the nature of preservation of brachiopods and the methods of study, employing serial sectioning techniques, suggest the possibility of detecting this unusual association in the fossil record.

Preliminary experiments with a confocal microscope (Sarastro 2000®) demonstrate its value in micropaleontology for photography and three-dimensional morphometric studies. High-quality images of objects in the size range of 100 to 2,000 μm can be obtained without application of nonremovable coating. Images can easily be electronically converted to stereopairs or displayed as single images. Images are in focus throughout and are superior to light photographs. Numerical data (x, y, and z coordinates) in almost any desired amount can be extracted from enough points on the visible surface to provide for the construction of a detailed topographic map of the surface. All of this can be done without manipulating the specimen once it has been mounted.

A nearly complete skull of Anchitheriomys from the Miocene of Nebraska allows description of the cranial foramina. In skull characters, Anchitheriomys most closely resembles Agnotocastor and Neatocastor among castorids; it retains primitive features that it shares with eutypomyids (position of the posterior palatine foramina, smooth palatal surface, nearly parallel tooth rows, retention of dP3) combined with derived features (elongate rostrum, procumbent incisors) that are shared only with Agnotocastor and Neatocastor. A new subfamily, Agnotocastorinae, is erected for this group of primitive beavers.

The description of Lophoranina precocious new species from the Late Cretaceous (early Maastrichtian) Ocozocuautla Formation, Chiapas, México, represents the first occurrence of Lophoranina in pre-Eocene strata. The discovery provides documentation that the evolutionary development of terraced lines in the genus trended from relatively few, undivided, symmetrical terraces to more numerous, divided, asymmetrical terraces, and that the overall carapace surface developed a lower relief and became more uniform through time. Terraced lines that appear to be nodose, in most cases, were probably spinose. The morphology of the dorsal carapace seems to support affinities of the Raninidae with the Homolidae.

Actinomycetes are Gram-positive prokaryotes that tend to form branching and fragmenting filaments, which in some groups form a sizable mycelium. They make up a large and important part of modern terrestrial microfloras but are not known extensively as fossils, although they have a long fossil history. Actinomycete-like fossils appear several times in the Precambrian: in the middle Precambrian Gowganda Formation of Ontario (Jackson, 1967), in the 2.0 Ga Gunflint Chert of Ontario (Lanier, 1987), and possibly in a lichen-like symbiosis in the 2.8 Ga Witwatersrand rocks of South Africa (Hallbauer and Van Warmelo, 1974), among others. Direct fossil evidence of actinomycetes is very rare in the Phanerozoic, and some “fossil” actinomycetes may be later contaminants (Knoll, 1977; Smoot and Taylor, 1983). Hyphae identified as actinomycetes are known from rod-like bodies identified as nematodes inside a decaying scorpion from the lower Carboniferous of Scotland (Stoermer, 1964), and from the interior of fern phloem cells from the Pennsylvanian (Smoot and Taylor, 1983). Unmineralized Actinomyces-like cells are known from calcite in bituminous lake-bed sediments from the early Cretaceous of Nevada (Bradley, 1963), and similar, poorly preserved fossils of a form called Actinomycites have been reported from the Jurassic of Scotland (Ellis, 1915). Actinorhizal nodules, formed by actinomycetes symbiotic with plant roots, have been described from the late Pleistocene (Baker and Miller, 1980).

Lacertasterias elegans and Schondorfia fungosa are new genera and species of multiarmed asteroids described from the Kinderhookian? (Mississippian) Gilmore City Formation of Iowa and the Chesterian (Mississippian) Haney Formation of Illinois, respectively. Based on ambulacral construction, the former belongs to the Paleozoic asteroid stem group whereas the latter is distinct from but closer to post-Paleozoic asteroids.

The multiarmed condition is atypical today; nevertheless, multiarmed species are morphologically varied and taxonomically widely distributed. The condition is considered problematic; it is uncertain whether or not multiarmed organization is adaptively neutral. Although only convergent with rather than ancestral to post-Paleozoic multiarmed asteroids, both new genera share important similarities with modern multiarmed predators, implying a predatory life mode for the fossils. The similarity between phylogenetically disparate Paleozoic and post-Paleozoic asteroids implies the multiarmed condition is beneficial, and benefits endured in spite of the major biotic changes that occurred around the end of the Paleozoic.

The Cretaceous Period (145–66 Ma) consisted of several oceanic anoxic events (120–80 Ma), stimulated by global greenhouse effects. The Oceanic Anoxic Event 2 (OAE2) occurred worldwide from the late Cenomanian to the early-middle Turonian, causing a significant faunal turnover, mostly in marine biota, pushing some species to the brink of extinction. Some organisms also underwent morphological changes, including reduction in size. This anoxic event drove other changes—e.g., in habitats or strategy of life. We show that stalkless crinoids (comatulids) from the Turonian of Poland adapted to unfavorable environmental conditions by reducing their body size. Furthermore, at the moment when environmental factors became favorable again, these crinoids regained their regular (pre-event) size. This phenomenon likely illustrates the so-called dwarfing mode of the Lilliput effect.

The first Silurian trilobites to be described from Alaska are of late Llandovery (Telychian) age. They occur with original cuticle intact in a white biosparite. Seven species have been identified, including Paracybantyx occidentalis n. sp., Ligiscus smithi n. sp., Calymene s.l. aff. C. iladon Lane and Siveter, 1991, Scotoharpes aff. S. raaschi Norford, 1973, Scharyia sp., a cheirurine belonging to either Radiurus Ramsköld, 1983, or Protocerauroides Chatterton and Perry, 1984, and an undetermined warburgelline. The fauna has close affinity to those described from similar lithologies in the Telychian of North Greenland. Machaeridians occurring with the trilobites include Turrilepas sp., Compacoleus sp., and Lepidocoleus cf. L. britannicus Withers, 1926.

The Somerset Shale Member (Mississippian: Valmeyeran) is a discontinuous shale at the base of the Salem Limestone in southern Indiana and central Kentucky. It is the only significant terrigenous unit within a thick sequence of shoaling carbonates deposited on the eastern side of the Illinois Basin over the Borden Delta siltstones. The Somerset Shale contains a diverse echinoderm fauna of blastoids (five species), crinoids (20 species), and echinoids (two species). Most of the species are known only from the Somerset or from carbonate rocks directly above and below the Somerset Shale. There remains a small number of species previously known mostly from terrigenous rocks (the Borden Delta) below the carbonates. This demonstrates that at least some of the faunal differences between the Borden crinoids and those of the overlying carbonates are the result of paleoecologic factors. The Somerset Shale may mark a useful biostratigraphic boundary defined by last occurrences of the genera Barycrinus, Cyathocrinites, and Actinocrinites and the base of the range of Batocrinus. The species Batocrinus somersetensis n. sp., Dizygocrinus calvus n. sp., and Barycrinus punctus n. sp. are described.

The Onychodontiformes is a poorly known sarcopterygian fish group, with four genera currently described, predominantly from the Middle-Late Devonian. A new onychodont, Bukkanodus jesseni n. gen. and sp., from the Fairy Formation, Victoria, Australia, is of Early Devonian (mid-late Pragian) age, representing one of the oldest known occurrences of this group. Other Pragian onychodonts are represented by a single lower jaw from China, while older occurrences (Lochkovian) include a lower jaw also from China and isolated teeth from Nevada. The Australian material, though disarticulated, includes skull, jaw, and palatal and dental specimens. These specimens share characteristics with younger onychodont taxa, including a laterally compressed tooth whorl with main and accessory rows containing an equal number of teeth, an anteriorly arched shape of the premaxilla, a lateral rostral bone participating in the orbital margin, parietals separated in the midline by small bones, the insertion of the basisphenoid region of the braincase into a posterior area on the parasphenoid, and an ethmoidal sensory canal running along the dorsal margin of the premaxilla rather than through the bone. Bukkanodus jesseni differs from other onychodonts in the presence of a distinct vomer, coronoids with fang pairs, a restricted herringbone pattern of ribs on enamel ridges of teeth, and the presence of a cluster of large pores on certain skull and jaw bones. The course of the ethmoid sensory canal and this cluster of pores are plesiomorphic features for the Onychodontiformes, also occurring in primitive sarcopterygian taxa such as Youngolepis, Powichthys, and Kenichthys. The opening of this cluster on the internal surface of the premaxilla resembles the rostral organ of derived coelacanths.

Abundant and well-preserved tetrapod footprints have been discovered in the Glenshaw Formation (Lower Conemaugh Group) in Wayne County, West Virginia. The tracks occur along at least three horizons within a 30-cm-thick stratigraphic interval about 15 m (50 ft) above the Brush Creek Limestone; they are of Missourian age. The tracks are preserved mainly as casts on the underside of thin-bedded, ripple cross-laminated sandstones and less commonly as molds in intervening dark-gray shales. Associated body fossils include Spirorbis worm tubes and washed-in plant debris. Facies characteristics indicate the tracks were formed along the margins of an ephemeral lake in a flood basin setting adjacent to delta plain fluviodeltaic channel systems. Short-lived lacustrine conditions were likely to have resulted from a seasonal tropical to subtropical climate.

Most of the tracks can be assigned to the ichnogenus Limnopus, making them one of the earliest known occurrences. At least five trackways are discernible with an external width ranging from 320 to 400 mm. Limnopus glenshawensis, a new ichnospecies, is herein proposed and various morphologic and locomotion parameters are quantified. Mean values include stride/manus, 407 mm; stride/pes, 411 mm; oblique pace/manus, 313 mm; oblique pace/pes, 317 mm; pace angle/manus, 82.4 degrees; pace angle/pes, 80.5 degrees; glenoacetabular distance, 329 mm; manus length, 87.2 mm; manus width, 104.2 mm; pes length, 121.4 mm; pes width, 112.7 mm. The tracemaker was most likely an eryopoid amphibian with a total length of slightly over 1 m.

Reticulate Hornera reteramae (Bryozoa, order Cyclostomata) have been discovered as free-lying, lyre-shaped colonies in the Castle Hayne Limestone (Eocene) in North Carolina. These specimens represent a striking instance of homeomorphy in colony form with the Late Mississippian genera Lyropora and Lyroporella of the order Fenestrata.

Bryozoans with reticulate growth habit most commonly develop upright colonies. Living representatives generally grow in quiet environments or microenvironments, and fossils are generally found in situ in quiet-water deposits. However, lyre-shaped Hornera reteramae occur in skeletal packstones inferred to have been deposited in a moderate-energy, shallow, open shelf environment near normal wave base. Upper Mississippian lyre-shaped colonies are preserved in skeletal packstones and grainstones in localized channels or on upper surfaces of low-angle cross-bedded sheets interpreted as high-energy, marine shoal deposits. Modification of the reticulate growth habit to low, peripherally weighted, free-lying structures apparently allowed invasion of higher energy sand bottoms, both in Mississippian and Eocene times.

The lower Famennian ‘Cyrtospirifer’ orbelianus brachiopod Zone established in Armenia by Abrahamyan (1957) (coeval to the crepida conodont Zone) contains an abundant and diverse brachiopod fauna that still remains poorly studied. In an effort to revise and update its systematic classification and to assess the brachiopod diversity in this area after the Kellwasser extinction event at the end of the Frasnian, our attention is here focused on rhynchonellides and athyrides. Six rhynchonellide species are described belonging to five genera as well as a single athyride species (Crinisarina pseudoglobularis n. sp.), which is new to science. The genus Crinisarina is reported for the first time in the South Armenian Block (SAB), which was then part of the northern margin of Gondwana. Some of the rhynchonellides identified were previously recognized in this area, but they require modern documentation and taxonomic reassessment. More particularly, it is the first time that the internal structure of Sartenaerus baitalensis (Reed, 1922) is illustrated, taking into account that it is the type species of a biostratigraphically significant Famennian genus. One of the oldest punctate rhynchonellide species, Greira transcaucasica Erlanger, 1993, is described for the first time from Armenia and its intraspecific morphological variability is documented quantitatively. From a paleobiogeographic viewpoint, the studied brachiopod fauna clearly shares affinities with contemporaneous ones from other regions of the Gondwanan northern margin that extend eastwards of the SAB to Afghanistan and Pamir, although there are also some endemic elements.

UUID: http://zoobank.org/798eb5f9-ad15-4d90-bc6a-ff22ee936438

Parablackwelderia is the oldest known stalk-eyed trilobite and thrived during the middle-late Cambrian (Guzhangian Age) in eastern Gondwanaland. the elongated palpebral lobe extends outward and forward from the anterior corner of the cranidium and shows positive allometry, becoming markedly longer and relatively thinner in large specimens. the animal occurred in muddy environments and may have been a predator that burrowed for concealment. Stalked-eyes were independently derived in several trilobite clades, but whenever they appeared were restricted to small numbers of taxa and thus do not appear to have served as a key innovation that promoted extensive diversification of species bearing the structure. the stalk-eyed condition in trilobites has a striking modern analog in the hypercephaly of diopsinid flies, where it is commonly associated with mate recognition and mate selection. We document the first occurrence of Parablackwelderia in Shandong, North China and describe a new species, Parablackwelderia luensis sp. nov.

The Eosaukia fauna is proposed for the upper Furongian trilobite assemblage from the interval spanning from the upper part of the Hwajeol Formation to the lowermost part of the Dongjeom Formation in the Taebaek Group, Taebaeksan Basin, Korea. It is characterized by the dominance of dikelocephalid trilobites comprising Eosaukia micropora, E. bella, E. acuta, Mictosaukia cf. M. globosa, and Taebaeksaukia spinata n. gen. n. sp. Taxonomic reappraisal of the genus Mictosaukia that has been employed as an upper Cambrian index taxon in eastern Gondwana reveals that more than half of the species of Mictosaukia belong in Eosaukia. This study clarifies the generic concept of Eosaukia, which provides a more reliable biostratigraphic correlation for the upper Furongian strata in eastern Gondwanan regions. The Eosaukia fauna is correlated with the “Mictosaukia” faunas from the upper Fengshanian of North China, upper Taoyuanian of South China, and upper Payntonian of Australia.