Brachyuran decapods (crabs) are rarely preserved in coastal environments and have not been documented in close association with dinosaur fossils. A crab referable to the Necrocarcinidae Förster, 1968, is here described from the Cenomanian Bahariya Formation, Bahariya Oasis, Egypt. The occurrence of a crab in a mangrove setting in association with terrestrial vertebrates is extremely unusual in the fossil record. Review of decapod occurrences from the region has resulted in placement of Portunus sp. of Roger (1946) within the Raninidae de Haan, 1839, and Lophoraninella cretacea (Dames, 1886) into the Galatheoidea Samouelle, 1819. The crabs of the Bahariya Formation were probably scavengers, feeding on vegetation and other organic material and were possibly a food source for fish and other vertebrates and invertebrates in the environment.

A new scolopendromorph centipede (Myriapoda: Chilopoda), Cratoraricrus oberlii n. gen. and sp., is described from the Nova Olinda Member of the Lower Cretaceous Crato Formation of northeast Brazil. The specimen is tentatively referred to the Scolopendridae based on possession of bisegmented tarsi and paramedian longitudinal grooves on the sternites. This specimen represents one of only four verifiable Mesozoic taxa.

Diagnoses based upon preservable carapace features are provided for the brachyuran families Carpiliidae, Palaeoxanthopsidae new family, Pseudoziidae, and Zanthopsidae, newly raised to family status. In order to make family and generic level assignments, characters of the dorsal carapace can be used successfully as proxies for soft-part morphology that is not commonly or never preserved in fossils. The identification of carpiliids and pseudoziids in the fossil record yields critical information about the time of divergence of these groups, no later than Eocene, and the relationships between those two families, the Eriphiidae, and the extinct Zanthopsidae. Because the timing of divergence of at least two xanthoid families is now known more accurately, more constrained phylogenetic studies can result. The Eocene to Recent Carpiliidae is restricted to one extant genus and five fossil genera. The Eocene to Recent Pseudoziidae contains the fossil genera Archaeozius new genus, Priabonocarcinus, and Santeezanthus as well as several extant genera; one extant genus, Euryozius, also has a fossil record. The Paleocene-Miocene Zanthopsidae embraces five extinct genera including Neoxanthopsis new genus. The new family Palaeoxanthopsidae includes four extinct genera, including Paraverrucoides new genus and Remia new genus and occurs in Maastrichtian-Eocene rocks. New combinations include Archaeozius occidentalis, Harpactoxanthopsis bittneri, Harpactoxanthopsis souverbei, Neozanthopsis bruckmanni, N. carolinensis, N. rathbunae, N. sonthofensis, N. tridentata, Ocalina straeleni, Palaeocarpilius mississippiensis, Palaeocarpilius valrovinensis, Paraverrucoides alabamensis, and Remia africana.

Plethopeltis armatus, and species of Leiocorpyphe, are shown to have in common a median ventral cephalic suture and thoracic axial rings with a poorly-defined articulating furrow and a strong transverse ventral ridge. In other characters they differ greatly, and to group them in the Plethopeltidae is open to question; this family may be polyphyletic. The median ventral suture is regarded as a cardinal character of Asaphida, but it is uncertain whether this character had a single origin or arose more than once. Leiocoryphe gemma may be a paedomorphic species derived from some Upper Cambrian trilobite with an effaced cephalon.

Late Ordovician jawed polychaete (Annelida) faunas from the type Cincinnatian region in the tri-state area of Indiana, Ohio, and Kentucky, North America, are discussed on the basis of an extensive and unique collection of more than 50,000 well-preserved scolecodonts. Approximately 40 to 50 multi-element species belonging to a dozen families are identified. Scolecodonts of polychaetes with prionognath, and particularly labidognath, type of jaw apparatus markedly dominate, whereas those of placognath and ctenognath taxa are very rare. The most common and/or characteristic genera include Oenonites Hinde, 1879; Kettnerites Žebera, 1935; Atraktoprion, Kielan-Jaworowska, 1962; Ramphoprion Kielan-Jaworowska, 1962; Protarabellites Stauffer, 1933a; Kalloprion, Kielan-Jaworoska, 1962; Leptoprion, Kielan-Jaworowska, 1966; Hadoprion Eriksson and Bergman, 1998; Mochtyella Kielan-Jaworowska, 1961; and Tetraprion? Kielan-Jaworowska, 1966. Members of the family Polychaetaspidae, particularly Oenonites species, generally dominate in abundance and number of species. The second most abundant family typically is either Ramphoprionidae or Paulinitidae. Overall, the taxonomic diversity seems to increase from the deeper water, shale-dominated, Edenian Kope Formation and upward in the succession to the shallower water, limestone-dominated, Richmondian Whitewater Formation. Five more or less distinct scolecodont associations were identified that are of potential biostratigraphic utility. Most families and genera identified have intercontinental distribution and can be identified also in approximately coeval strata of the Baltic paleocontinent. However, the faunal composition differs between these regions, especially at the species level.

Chen and Yao (1993) described diverse echinoderm communities from Ordovician through Upper Carboniferous rocks in western Yunnan, China—the first monographic treatment of Chinese echinoderms in almost 70 years. This paper is the first in a series of studies re-describing echinoderm taxa from these biogeographically important Paleozoic assemblages. Pentremites globosus Chen and Yao, 1993 is designated as the type species of Sinorbitremites, a new genus of orbitremitid blastoids. Pentremites ovatus Chen and Yao, 1993 is placed in synonymy with Sinorbitremites globosus (Chen and Yao, 1993). Cryptoschisma conicum has been reassigned to Breimeriblastus, a hyperoblastid blastoid.

Acid-resistant specimens of trilobites were recovered from the dissolved residues of lime mudstone collected from the lower part of the Machari Formation, Yongwol Group, Taebaeksan Basin, Korea. One of the samples yields a trilobite assemblage comprising Lejopyge armata (Linnarsson, 1869), Lisogoragnostus coreanicus n. sp., agnostid genus and species indeterminate, ammagnostid genus and species indeterminate, clavagnostid genus and species indeterminate, Cyclolorenzella sp., and Eoshengia? sp. The stratigraphic interval yielding the trilobite assemblage is herein designated as the Lejopyge armata Zone, which is correlated well with the upper Middle Cambrian biozones established elsewhere. This provides the first biostratigraphic reference point for the upper Middle Cambrian sequence of the Yongwol Group and fills partially the biostratigraphic gap between the Tonkinella (middle Middle Cambrian) and the Glyptagnostus stolidotus (uppermost Middle Cambrian) zones in the Machari Formation.

Two non-trilobite arthropods are described from the Emigrant Formation (Lower Cambrian-Lower Ordovician) in the Silver Peak Range, Esmeralda County, Nevada. A Middle or Upper Cambrian “arachnomorph” arthropod with a phosphatic exoskeleton has been noted in previous faunal lists, but has not been previously described. This fossil is here named Quasimodaspis brentsae gen. et sp. nov. Q. brentsae belongs in the Aglaspidida, a close outgroup to the true chelicerates; this is the second report of an aglaspidid from the Great Basin. Esmeraldacaris richardsonae gen. et sp. nov. is a newly discovered arthropod from the lower Ordovician, from beds transitional between the Emigrant Formation and the overlying Palmetto Formation. It is a survivor of an early arthropod lineage that does not belong in any extant taxon, but which may also include the Ordovician Corcorania and the Cambrian Mollisonia.

The Cambrian–Ordovician boundary is a type 1 depositional sequence boundary with dramatic local erosional incision in restricted marine facies on the easternmost New York Promontory. The systemic boundary is bracketed below by Late Cambrian, upper Cordylodus proavus Zone (s.s). conodonts from carbonates of the upper Little Falls Formation (=Whitehall Formation, abandoned). Presumed Lower Ordovician ellesmeraceratoid cephalopods from the upper Little Falls are uppermost Cambrian and among the oldest known in North America. The overlying deepening–shoaling cycle of the Tribes Hill Formation (=Cutting and Great Meadows Formations, abandoned) is the local expression of a lowermost Ordovician (Rossodus manitouensis Zone) depositional sequence recognizable across Laurentia. Complete replacement of conodonts takes place in the late Tremadocian or Tremadocian–Arenigian boundary interval with onlap of the “Fort Ann Formation” across the paleokarst cap of the Tribes Hill. The trilobites Hystricurus sp. and Symphysurina myopia Westrop new species occur in less restricted, thrombolitic facies of the middle Tribes Hill that have the highest conodont diversity. Ulrichodina Furnish, 1938, emend. is regarded as the senior synonym of the conodont Colaptoconus Kennedy, 1994 (=Glyptoconus Kennedy, 1980).

Euphylax feldmanni new species from the late Eocene Hoko River Formation, northwestern Olympic Peninsula, Washington, represents the first occurrence of Euphylax in pre-Oligocene strata, the earliest fossil record for the subfamily Podophthalminae, and the first record of the genus from the eastern North Pacific. This small, aberrant crab is one of 26 described species of decapod crustaceans from an unusual allochthonous invertebrate assemblage of the upper Eocene Hoko River Formation conglomerates at Kydikabbit Point, on the Makah Indian Nation, northwestern Olympic Peninsula, Washington, U.S.A. Species of Euphylax live today in the Pacific Ocean from Baja California south to Peru and Chile, and have been found as fossils from the Pleistocene of Jamaica, the Miocene of Costa Rica, Brazil, and Haiti, and questionably from Malaysia and Japan. The discovery of a fossil species of Euphylax from the Pacific Northwest, U.S.A. greatly expands the paleobiogeography of the genus.

Two new genera, Poliellaites and Piochella, and six new species, Eokochaspis? cabinensis, Nyella? plana, Poliellaites gloriosa, Piochella peasleensis, Poliella ovala, and Stephenaspis highlandensis, are described from the Susan Duster Limestone and Log Cabin members, Pioche Shale. Kochaspis Resser, 1935, and Kochaspis liliana (Walcott, 1886) are redescribed based on new material. In addition, several species from the Pioche Shale, that are not addressed in our previous reports are discussed in relationship to existing species and local occurrence. The trilobite diversity of the Poliella denticulata Biozone (new) within the study area is 17 genera and 35 species, occurring in five faunal assemblages.

Two new Neogene South American croakers of the genus Plagioscion (Perciformes, Sciaenidae) from marine sediments, Plagioscion marinus and Plagioscion urumacoensis, are described. These are otoliths from the lower Miocene Castillo, Cantaure and upper Miocene Urumaco Formations of the Neogene Venezuelan basin, respectively. An additional undetermined fossil species of Plagioscion was also collected from the upper Miocene to lower Pliocene Cubagua Formation. Using the function total fish length = 13.7187 + 50.8399 ∗ Ln otolith size, the total length of P. marinus n. sp. is inferred to be from 6.05 to 38.1 cm, and for the specimens of P. urumacoensis n. sp. it is 63.3 cm. The length distribution of the fossil species overlaps the length distribution of the living freshwater species.

Conodont elements other than those with platform ledges along the processes have often been unrecognized or disregarded in reconstructions and phylogenetic discussions of Ordovician “platform conodont genera.” The platform elements are larger than the other element types and often exhibit more rapid evolutionary changes in morphology. Nevertheless, to understand the evolution of, and relationships between and among “platform genera,” it is necessary to also consider the associated ramiform and geniculate elements. Thus, on the basis of large collections, together comprising 10,800 elements from Sweden and southern China, all element types of Lenodus antivariabilis (An, 1981), L. variabilis (Sergeeva, 1963), Yangtzeplacognathus crassus (Chen and Zhang, 1993) and Eoplacognathus pseudoplanus (Viira, 1974) are described and discussed. All these species had seven morphologically distinct element types, and probably seventeen individual elements in each apparatus. Ancestors and descendants of these species are discussed more briefly and it is concluded that the ramiform and geniculate elements also are characteristic within each lineage.

The Middle Eocene (Lutetian) bee faunas of Eckfeld and Messel, Germany are revised. In addition to the previously known Electrapis electrapoides (Lutz), five additional species are recognized. Four new species of the Electrapini (Apidae: Apinae) are described: Electrapis micheneri Wappler and Engel, E. prolata Engel and Wappler, Protobombus pristinus Wappler and Engel, and P. messelensis Engel and Wappler. In addition, the new genus Pygomelissa Engel and Wappler is proposed for Pygomelissa lutetia Engel and Wappler new species, which cannot presently be classified into any tribe of the Apidae. The tribe Megachilini (Megachilidae: Megachilinae) is also recorded from Eckfeld but in the absence of any body fossil. Megachilines include the leaf-cutter bees (Megachile) and from the occurrence of the distinctive semicircular damage they produce in leaves, we conclude that such bees were also present in the fauna. The bee fauna is compared with that of the contemporaneous Baltic amber. As with Baltic amber, the majority of bee specimens are from the advanced eusocial lineages of the corbiculate Apinae. Lastly, comments are made on the phylogenetic and paleobiological significance of the faunas.

Chondrichthyan spines and dermal denticles are reported from the Middle Pennsylvanian Minturn Formation, Eagle County, Colorado. The most common element is a dorsal finspine referred to Ctenacanthus buttersi St. John and Worthen, 1883. Some of the specimens are more complete distally than the holotype and only previously figured specimen of C. buttersi. Less common remains include a dorsal finspine referred to Acondylacanthus nuperus St. John and Worthen, 1883, a smooth-ribbed dorsal finspine close to “Ctenacanthus” furicarinatus Newberry, 1875, a spine fragment probably referrable to Physonemus sp., and two large-noded dorsal finspines probably referrable to two different species of Bythiacanthus. Dermal denticles are referred to Petrodus patelliformis M'Coy, 1848. Ctenacanthus buttersi finspines and some large cladodont teeth, referred to “Symmorium” occidentalis (Leidy), 1859, may belong to the same species. This conjecture is based mainly on the relative abundances of chondrichthyan teeth found at the same locality.

The largest known trilobite fossil, a virtually complete articulated dorsal shield of the asaphid Isotelus rex new species, has been recovered from Upper Ordovician (Cincinnatian, Richmondian) nearshore carbonates of the Churchill River Group in northern Manitoba. At over 700 mm in length, it is almost 70 percent longer than the largest previously documented complete trilobite, and provides the first unequivocal evidence of maximum trilobite length in excess of one-half metre. Comparisons with other fossil and extant members of the phylum suggest that in terms of maximum linear dimensions it was among the biggest arthropods ever to have lived. Sediments of the Churchill River Group were deposited in an equatorial epeiric setting and the extremely large size of I. rex n. sp. thus marks a striking example of low-latitude gigantism, in sharp contrast to the widespread phenomenon of “polar gigantism” in many modern marine benthic arthropods. Lack of extensive epibiontic colonization of the exoskeletal surface and the presence of large distinctive trace fossils in the same unit suggest that I. rex n. sp. may have been a semi-infaunal predator and scavenger that employed a shallow furrowing and probing mode of benthic feeding. The extinction of the isotelines (and virtually the entire asaphide lineage) at the end of the Ordovician cannot be related to the near contemporaneous achievement of exceptionally large adult size in some representatives. Failure to survive the terminal Ordovician extinction event was most likely a consequence of a pelagic larval life-style that proved ill-adapted to the rapid onset of global climatic cooling and loss of tropical shelf habitats.

A new species of the genus Nothosaurus from the Lower Muschelkalk of Winterswijk, The Netherlands, shows relatively plesiomorphic features such as a relatively forward position of the pineal foramen. The jugal enters into the ventral margin of the orbit, which would also be regarded as plesiomorphic, were it not that this feature optimizes unequivocally as a reversal and, hence, as a diagnostic (derived) character of the new taxon. The new taxon does not, however, increase the fit of the cladogram for the phylogenetic relationships within Nothosaurus to the stratigraphic record of the genus. The basal position of Nothosaurus juvenilis remains problematic.

A new diverse Famennian echinoderm fauna (∼600 specimens representing 33 genera and 47 species) dominated by blastoids and cladid, small-calyx camerate, and flexible crinoids is reported from the Hongguleleng Formation, Junggar Basin, Xinjiang-Uygar Autonomous Region, China. Two stratigraphically distinct pelmatozoan faunas were collected: one from the lower member of the Hongguleleng Formation (crepida Zone to marginifera Zone) and one from the upper member of the Hongguleleng Formation (praesulcata Zone). Both faunas are distinctively “Carboniferous” in aspect. The older fauna is dominated by cladids and small-calyx camerates, whereas the younger fauna is dominated by blastoids.

Discovery of these two faunas has more than doubled the number of Famennian echinoderm specimens known in the world and more than quadrupled the number of known taxa. Latest Devonian (Famennian) and earliest Carboniferous stemmed-echinoderm (pelmatozoan) faunas traditionally have been considered to be very low diversity relative to earlier Frasnian and later Early Carboniferous faunas. Furthermore, Carboniferous pelmatozoan faunas seemingly arose suddenly, with unclear ancestral ties to Devonian taxa. The Hongguleleng faunas are critical in understanding pelmatozoan biogeography and evolution in the aftermath of Devonian extinction event(s) prior to the Carboniferous echinoderm diversification, as they indicate that diversification and re-radiation of stemmed echinoderms already were well underway before the close of the Famennian.

Collections from field excursions in 1993 and 1995 include seven new taxa of blastoids and nine new taxa of crinoids among the twenty-four total taxa reported. New blastoid taxa are Emuhablastus planus, Tripoblastus plicatus, Breimeriblastus pyramidalis, B. gracilis, Conoblastus invaginatus, Sinopetaloblastus grabaui, and Hyperoblastus emuhaensis. Together with collections from 1991, we have amassed 333 blastoid specimens, representing 13 genera and 15 species. Emuhablastus planus, new genus and species, is the oldest genus of the Family Codasteridae, extending the familial record back from the Viséan to the Famennian. The hyperoblastid genera, Breimeriblastus, new genus, and Conoblastus, new genus, apparently represent transitional genera between a Pentremitidea-like ancestor and a Pentremites-like descendant. These taxa imply that the fissiculate-spiraculate transition may have occurred in a mosaic fashion during the Middle to Upper Devonian. Hyperoblastus emuhaensis, new species, is the first report of the genus from rocks of Famennian age or from Asia.

New crinoid taxa include Athabascocrinus orientale, Hexacrinites pinnulata, Abactinocrinus devonicus, Euonychocrinus websteri,? Parisocrinus nodosus,? P. conicus, Bridgerocrinus discus, Julieticrinus romeo, and Sostronocrinus quadribrachiatus. In addition, we propose several other taxonomic reassignments based on new collections. Uperocrinus zhaoae is reassigned to the genus Actinocrinus based on the presence of pentagonal or hexagonal primibrachials in the cup, even though the primibrachials have a pseudo-quadrate appearance. Bridgerocrinus delicatulus is reassigned to Logocrinus based on the presence of three, rather than two, primibrachials. Sostronocrinidae, new family, is erected for genera with 20 arms that otherwise might be placed in the Family Scytalocrinidae. Genera included within the Sostronocrinidae, new family, are Sostronocrinus, Hertocrinus, Tundracrinus, and Amadeusicrinus new genus. Bridgerocrinus minutus is reassigned to the genus Sostronocrinus. Pachylocrinus subpentagonalis is reassigned to Amadeusicrinus new genus. “Decadocrinus” xinjiangensis is reassigned to Grabauicrinus new genus, which is erected for decadocrinids with 10 arms, all of which branch on the second primibrachial.

A new genus and species of hipposiderid bat is described from an early to middle Miocene cave deposit (AL90 Site, estimated to be between 15 and 20 million years old) at Riversleigh, northwestern Queensland, Australia. Archerops annectens new genus and species is interpreted to be most closely related to species of the Asian genera Coelops and Paracoelops and southeastern Africa's Cloeotis percivali, none of which has a fossil record. The new Australian fossil bat: 1) shares a number of apomorphies with species of Coelops, Paracoelops, and Cloeotis; 2) lacks striking autapomorphies characterizing each of the three extant genera; 3) exhibits few autapomorphies its own; and 4) forms a structural intermediate between plesiomorphic Tertiary hipposiderids (e.g., Brachipposideros species) and the aberrant Coelops, Paracoelops, and Cloeotis species.

A geometric analysis of lophophore shape and arrangement in the fenestrate dendroid graptolite genus Dictyonema reveals that the shape of the zooid domain in the majority of Dictyonema species colonies is highly elliptical, with the long axis of the ellipse perpendicular to the proximodistal axis of the stipe. A complex lophophore, bilaterally symmetrical and consisting of two tentaculated arms that are laterally directed and perpendicular to the stipe axis, provides the best geometric solution to completely filling the elliptical zooid domain seen in the majority of Dictyonema species.

Working under the assumption that fenestrate graptolites, like fenestrate bryozoans, needed to form a continuous filtering surface with contact between adjacent lophophores, two optimum close-parking models exist for lophophores with elliptical zooid domains: either a proximodistal-row arrangement or a lateral-row arrangement of the lophophores. Of the two possible geometries, the most probable close-packing arrangement of hypothetical biplumed lophophores within the fenestrate graptolite meshwork is in proximodistal rows.