The assemblage of demosponge and hexactinellid sponges described here was collected from the Lower Cambrian, Atdabanian, Yu'anshan Member of the Chiungchussu Formation, at the Maotianshan and Xiaolantian sections in Chengjiang County, Yunnan Province, 70 km southeast of Kunming. The sponges occur in relatively massive to weakly graded-bedded, grayish-yellow mudstone and silty mudstone. They are associated with other soft-bodied and skeletonized fossils. The new demosponge species and genera Choiaella radiata, Allantospongia mica, and the questionable sponge Parvulonoda dubia are described, along with new specimens of Leptomitus teretiusculus Chen, Hou, and Lu, 1989, the hexactinellid sponge, Triticispongia diagonata Mehl and Reitner, 1993 and the probable hexactinellid sponge, Saetaspongia densa Mehl and Reitner, 1993.

The sponges occur in what may be distal turbidite deposits, and they may have been buried essentially in situ by these argillaceous accumulations.

The graptolite, Bohemicograptus bohemicus tenuis (Bouček, 1936), was collected with additional hexactinellid sponges from the Roberts Mountains Formation in the Snake Mountains of Elko County, Nevada, and dates the sponge beds as Ludlovian. To the modest fauna of hexactinellid sponges described by Rigby et al. (1991), can be added the new sponge genera and species Divaricospongia dilata and Fistellaspongia inclinata. The new species, Gabelia intermedia, is intermediate in size between the moderately fine-textured Gabelia pedunculus Rigby and Murphy, 1983, and the large Gabelia giganta Rigby et al. 1991. Additional specimens of Gabelia pedunculus were collected in association with well-preserved specimens of Gabelia fasiculata Rigby et al. 1991, which show additional skeletal and canal details. Associated coarse root tufts and patches of protosponge skeletal mesh were also discovered as part of the new collections and are described here, although not generically nor specifically identifiable.

A brachiopod fauna from the upper part of the Wadleigh Limestone, Alexander terrane, southeastern Alaska, is of late Frasnian age and includes the new taxa Gypidula cornuta alaskensis n. subsp., Gypidula upatensis n. sp., Gypidula perryi n. sp., Gypiduloides craigensis n. gen. and sp., Parapugnax schmidti n. sp., Westbroekina chaconenesis n. gen. and sp., Emanuella altus n. sp., Emanuella neumani n. sp., Adolfispirifer sanjuanensis n. sp., Theodossia albertoensis n. sp., Cyrtospirifer paridaensis n. sp., and Tenticospirifer wadleighensis n. sp. A few other taxa are cosmopolitan or conspecific with species known from elsewhere in western North America. The fauna overall may have North American affinities but includes an unusual number of previously undescribed forms. This lends support to the view, based on the affinities of Frasnian conodonts from this same locality (Savage, 1992) and Famennian brachiopods described from nearby (Savage et al., 1978), that these Alexander terrane faunas were not in general communication with Late Devonian North American cratonic faunas to the east.

Several biostratigraphically important gastropod genera are described from Alberta, British Columbia, Yukon Territory, and the District of Mackenzie. Malayaspira is present in the mid-Ibexian Kechika Group. Palliseria, Maclurites, Teiichispira, Malayaspira, Barnesella, and Ceratopea occur in the Skoki Formation (highest Ibexian and lower Whiterockian) and Helicotoma and Palliseria in the Sunblood Formation (lower Whiterockian). The largest known Teiichispira operculum is illustrated. The forms are particularly useful for age determination within relatively narrow limits and most of the taxa are readily identified in the field.

The presence of Swiftopecten Hertlein, 1936, in Patagonia (Argentina), a region situated in the southeastern extreme of the South American continent, is the oldest and southernmost fossil record of the genus. Furthermore, its occurrence during the Late Eocene in the circum-Antarctic region suggests that its origin was in the Southern Hemisphere; it has been known from Japan and the eastern Pacific, ranging from Miocene to Holocene (Moore, 1984). Swiftopecten iheringii new species, from the Late Eocene-Early Miocene sedimentary sequence of Patagonia, is described and illustrated.

Molluscan assemblages from upper middle Eocene deposits of southwestern Washington represent a regional biotic system that provides independent evidence of a range of depositional environments in a delta. Four marine molluscan assemblages reflect a subtropical fauna that inhabited an inner neritic to upper bathyal gradient down the prodelta slope. Comparisons with Recent molluscan taxa indicate changing trophic structures from dominantly infaunal filter feeding in the shallow, coarser-grained substrate to dominantly infaunal deposit feeding in the fine-grained mud. A very high diversity of carnivorous gastropods indicates that the biocenosis included a wide array of predominantly errant, soft-bodied invertebrate prey. The most shallow marine assemblages show evidence of dense Turritella patches within infaunal bivalve-dominated associations, indicating mosaics of distribution across a soft-sediment substrate. Low diversity marginal-marine and freshwater assemblages show faunal links with each other. They indicate interdistributary bay and marsh environments that are commonly part of a river-dominated delta.

The Early Permian (late Sakmarian to early Artinskian) adrianitid ammonoid Nevadoceras steelei new genus and species occurs in a fauna containing the ammonoids Properrinites Elias, Prothalassoceras Böse, Daraelites Gemmellaro, Almites Toumanskaya, Bamyaniceras Termier and Termier, Akmilleria Ruzhencev, Agathiceras Gemmellaro, Metalegoceras Schindewolf, Stenolobulites Mikesh, Glenister, and Furnish, Crimites Toumanskaya, Neocrimites Ruzhencev and the conodonts Sweetognathus whitei (Rhodes) and Mesogondolella bisselli (Clark and Behnken). This fauna occurs in a concretionary interval within micritic basinal facies of the Dry Mountain trough at Portuguese Springs, White Pine County, east-central Nevada.

Recurring associations of the trilobite ichnogenus Rusophycus with various “worm” burrows suggest an interaction between the two tracemakers, specifically, capture of the worm by the trilobite. An exceptional ichnofossil from the Upper Ordovician of southwestern Ohio shows characters consistent with previously described “trilobite hunting burrows” from Cambrian and Silurian strata. Preserved in convex hyporelief is R. carleyi, attributable to the trilobite Isotelus, on which is superimposed the case of a worm burrow of the ichnogenus Palaeophycus. The cast of the worm burrow appears to have been truncated by the digging activities of the trilobite, suggesting its predation of the worm. The exquisite preservation of ventral axial morphology of the trilobite distinguishes this Rusophycus from simpler bilobate forms attributable to filter-feeding behavior. Congruency in the preservation of worm and trilobite trace supports the conclusion that both were created at the same time, as the trilobite exited the intrastratal burrow. This is the first report of a trilobite hunting burrow from the Ordovician, and the first evidence for predatory behavior for the trilobite genus Isotelus.

Previously undescribed holes on the calyx of single specimens of the blastoids Pentremites and Cordyloblastus are circular in plan view, penetrate the test at a right angle, and are found in the interambulacral region. The same features characterize holes on 23 specimens of the Mississippian blastoid Orophocrinus. The holes are interpreted as biogenic in origin; examples of multiple complete holes on individual specimens and of incomplete holes on some blastoids indicate that the holes represent parasitism rather than predation. The similarity of these holes to those previously described in nucleocrinids and crinoids suggests that they were produced by platyceratid gastropods or closely related taxa.

A true interreef crinoid fauna lacking components of reefal facies is reported from the Ludlovian of the Mississinewa Shale Member of the Wabash Formation in northern Indiana. The Mississinewa facies that contains this fauna is a dolomitic siltstone or a silty dolomite. The crinoid association reported is composed entirely of new species and is different from other reef and reef-associated, interreef, and non-reef crinoid associations. New species described, herein, include the following: Dimerocrinites (Eucrinus) ankylos n. sp., Periechocrinus shaveri n. sp., Bohemicocrinus? occidens n. sp., Macrostylocrinus styo n. sp., M. homalos n. sp., Gissocrinus hypselos n. sp., and Dendrocrinus diaphoros n. sp. This may be the first occurrence of Bohemicocrinus from outside Bohemia.

Monograptus crinitus Wood is made the type species of a new genus, Crinitograptus; a slender, nilssoni Biozone, Ludlow graptolite typified by unusual lidded thecae. Chemically isolated material from North Germany, previously placed in the genera Barrandeograptus and Pomatograptus are placed in synonymy with C. crinitus, a rare, but relatively widely recorded form. Crinitograptus crinitus is an integral part of the globally recognized Ludlow burst of evolution in the graptoloids, and it probably evolved from a nilssoni Biozone lobograptid.

Early Devonian (Lochkovian; eurekaensis Zone) conodonts occur in discontinuous limestone beds in the Caballos Novaculite at five localities in the northwestern half of the Marathon uplift, west Texas. Similar conodont faunas at all five localities indicate that the limestone beds lie at one biostratigraphic horizon within the Caballos. The upper novaculite member directly overlies the limestone horizon at one locality, giving the upper novaculite a maximum age of Lochkovian. The limestone beds are dominantly skeletal calcarenites that represent shallow-water carbonate material transported into a deeper water setting by gravity processes. Restriction of the limestones to the northwestern margin of the uplift and provenance of reworked clasts and redeposited Ordovician and Silurian conodonts suggest a North American shelf source and are evidence of the close proximity of some strata exposed in the Marathon uplift to North America in the Early Devonian. Icriodus gravesi n. sp. is described from the limestone fauna.

The Plum Brook Shale of north-central Ohio lies disconformably between the Eifelian (lower Middle Devonian) Delaware Limestone and the middle Givetian (upper Middle Devonian) Prout Dolomite. Its diverse conodont fauna indicates that it represents a transgression into the area in earliest Givetian time accompanied by the products of a notable adaptive radiation within two lineages of Icriodus. One of these (I. expansus Group) includes I. expansus, I. arkonensis and I. brevis, and complete intergradation of forms suggests that the group at this level involves conspecific ecotypes. A more extensive radiation involved descendants of I. regularicrescens (I. regularicrescens Group), including three new species, I. eriensis, I. janeae and I. ohioensis. Other representatives of this lineage occur here as well as in strata of comparable age in the type region of the Givet Limestone as described by Bultynck (1987). A third lineage is represented by I. excavatus in both areas, but evidence of radiation within this branch is limited to the Givet Limestone. Remarkable diversity also occurs among forms considered herein to involve Polygnathus pseudofoliatus and its descendants. The existence of intermediate forms and shared characteristics between and among the various species, including some that first appeared well before the end of the Eifelian, implies that they may be conspecific ecotypic variants at this level. New morphotypes within this group are treated informally. The greatest overall diversity occurs just above the basal Plum Brook, in strata interpreted to reflect inner-sublittoral conditions. The entire Plum Brook belongs to the upper ensensis Zone. A considerable part of the type Givetian placed in the Lower varcus Subzone by Bultynck (1987) lies below the lowest occurrence of its index species (P. timorensis); it contains some of the species found in the Plum Brook, and much of this section may also belong to the ensensis Zone.

The Upper Missourian to lower Wolfcampian sequence (middle Kansas City through lower Council Grove Groups) of the Midcontinent U.S.A. (Kansas, Oklahoma, Nebraska, and Missouri) is divided into seven biostratigraphic zones defined chiefly upon first occurrences of Streptognathodus species. In ascending order, these are the: 1) Streptognathodus gracilis Zone; 2) Streptognathodus firmus Zone; 3) Streptognathodus pawhuskaensis deflectus Zone; 4) Streptognathodus virgilicus Zone; 5) Streptognathodus brownvillensis Zone; 6) Streptognathodus wabaunsensis s.l. Zone; and 7) Streptognathodus aff. barskovi Zone. The diagnostic Permian genus Sweetognathus first appears in the lower part of the S. aff. S. barskovi Zone. These zones coincide generally with Upper Carboniferous–Lower Permian conodont zones of Russia. Streptognathodus virgilicus, a new species common in the upper Shawnee and Wabaunsee Groups, is described.

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.

A new genus and species of deer, Lucentia iberica, is described from the lower Turolian (MN 11) locality of Crevillente 2 (Alicante province, Spain). Eostyloceros pierensis Thomas, 1951 from Piera (Barcelona province) is also included in the new genus. The two-tined Lucentia is not a representative of Muntiacinae. From the emplacement on the cranial cavity and moderate backward inclination of the pedicles, and from the monopodial construction of the antlers, Lucentia is probably the sister group of the clade Cervinae + Odocoileinae. The hypothesis that Lucentia is most closely related to Cervinae is poorly supported by dental features. The Cervinae-Odocoileinae split must have occurred during the late Miocene and it being later, during the Pliocene, when the different lineages acquired the lateral metacarpal reduction, either plesiometacarpal or telemetacarpal states.

Early Permian massive corals define a narrow zone (the Thysanophyllum coral belt of Stevens, 1982) that surrounded the northern and western margins of Pangaea from the southern Ural Mountains through western North America to Bolivia (Stevens, 1982; Wilson, 1990). This belt appears to have been essentially continuous in the Wolfcampian, and although massive corals persisted along this belt into the Leonardian, they were restricted to many fewer localities.

The fauna of the lower Chickabally Member of the Budden Canyon Formation, a part of the Cretaceous Great Valley Sequence in the Cottonwood District (Figures 1, 2) of northern California, was described by Murphy (1975). At that time, two specimens of the species described here were known, but they were not complete enough to be identified or classified. Recently, Embree collected three additional specimens from the same horizon that enable us to classify the taxon with the Heteroceratidae. However, the rate of whorl expansion of the cross section of the conch and the open coiling are different from all other Heteroceratidae and we regard it, like much of the associated fauna, as a genus and species endemic to California.