The calcareous heteractinid sponge Wewokella solida Girty, 1911, is reported from Colorado for the first time. Triactine-based skeletons are well preserved and dermal and gastral layers are composed of smaller spicules than those in the main wall of the many specimens. A fragment of an unnamed demosponge, possibly related to Heliospongia Girty, 1908, and fragments of root tufts occur with Wewokella in the Middle Pennsylvanian Minturn Formation near McCoy, in Eagle County, Colorado.

A single specimen of the new dictyonine hexactinellid species Verrucocoelia biswasi was collected from the Middle Eocene Fulra Limestone from Lakhpat Fort, Kutch, western India. The euretoid species is broadly bowl-shaped, 7–8 cm wide and 5–6 cm high, with walls of branched to weakly anastomosed tubes that extend upward and outward from a simple, unfluted, walled spongocoel. Skeletal strands diverge upward and outward from near the gastral surface of each tube. The sponge occurs in silty tan marl with abundant alveolinids and less common other large foraminifera, bivalves, and gastropods in sediments thought to have accumulated in a quiet, sheltered environment, possibly a lagoon.

Microborings in the Late Ordovician tabulate corals Catenipora rubra (a halysitid) and Manipora amicarum (a cateniform nonhalysitid) and in an epizoic solitary rugose coral differ from nearly all of those previously reported in Paleozoic corals. These microborings were formed within the coralla by endolithic algae and fungi located beneath living polyps. Comparable structures in the Late Ordovician tabulate Quepora ?agglomeratiformis (a halysitid) represent algal microborings, not spicules, and halysitids are corals, not sponges as suggested by Kaźmierczak (1989).

Endolithic algae in cateniform tabulates relied primarily on light entering through the outer walls of the ranks rather than through the polyps; lacunae within coralla permitted appropriate levels of light to reach many corallites. The direction of boring was determined by corallum microstructure and possibly also by the distribution of organic matter within the skeleton. There is an apparent inverse correlation between boring activity and coral growth rate.

The location and relative abundance of pyritized microborings within calcareous coralla can be established quantitatively and objectively from electron microprobe determinations of weight percent sulfur along appropriate traverses of the coral skeleton. The distribution of such microborings in Catenipora rubra and Manipora amicarum is comparable to algal banding in modern corals; this is the first report of such banding in the interiors of Paleozoic corals. Change in the intensity of boring within each corallum was evidently a response to variation in the linear growth rate of the coral, or to fluctuation in an environmental factor (perhaps light intensity) that could control both algal activity and growth rate in these corals. Change in the algal boring intensity and linear growth rate of the coral was generally but not always seasonal and usually but not invariably associated with change in the density of coral skeletal deposition.

Cyclic bands of boring abundance maxima within fossil colonial corals provide a measure of annual linear growth comparable to the widely accepted method based on skeletal density bands. Algal bands are more sporadically developed than density bands within and among coralla, thus increasing the difficulty of interpretation. Fluctuations in the abundance of algal microborings apparently provide a detailed record of changes in the linear growth rate of colonies and of individuals within colonies. Combined analyses of microboring abundance and skeletal density will contribute significantly to our understanding of the biological and environmental factors involved in endolithic activity and coral growth.

Rugose and tabulate corals from the Lower Permian (Wolfcampian) part of the Bird Spring Group in Arrow Canyon, Arrow Canyon Range, Clark County, Nevada, comprise eight species in eight genera. Stylastraea rowetti n. sp. is the first unequivocal record of this genus west of Texas in North America. Heritschiella girtyi, the only endemic North American waagenophyllid genus and species, is recorded outside Kansas for the first time. Paraheritschioides stevensi formerly was known only from northern California. The other species also occur elsewhere in the Permian of Nevada and nearby. This southeast Nevada shelf area has the first known intermixture of corals from the Durhaminid Coral Province and subprovinces of far western North America and the Cyathaxonid Coral Province of middle and southwestern North America.

The endolithic mytilid bivalve, Lithophaga palmerae n. sp., from the Upper Eocene Ocala Limestone of north-central Florida, sheds new light on the evolution of lithophagids with its unspecialized morphology and highly specialized mode of life. Lithophaga palmerae n. sp. inhabited dead and living coral as indicated by orientation evidence. In living coral, the anterior end of the borehole was sealed off with thick, continuous, “false floors” of CaCO3, as the posterior end was extended to keep pace with coral growth. To date, this new species of lithophagid has been found associated with only one host coral, Actinastrea cf. A. incrustans (Duncan). Association with living coral is found today in L. bisulcata (d'Orbigny) and L. dixonae Scott from the Caribbean and in several Red Sea and Indo-Pacific lithophagids. In the fossil record, live-coral boring has been reported from the Miocene of the Vienna Basin of Austria and from the Pleistocene of Grand Cayman Island in the Caribbean. Lithophaga palmerae n. sp. provides a valuable ancestral link in the evolution of Lithophaga by extending the range of live-coral boring back to the Eocene of Florida.

The Middle Devonian brachiopod genus Cyrtinoides, described from the southern Urals, is a senior subjective synonym of Mucroclipeus, previously known only from eastern and western North America. The Middle and Late Devonian cyrtinid brachiopod genus Komiella, previously known only from the Timan Range of eastern Europe, is identified from west-central Alaska and Nevada. A new family Komiellidae is proposed. New species are Komiella gilberti, K. magnasulca, and K. stenoparva. Known species of both genera occupy carbonate platform foreslope facies or shelf basins, allowing open marine migration via peripheral biofacies.

The euomphalacean gastropod Lytospira gerulus n. sp. is described from the Middle Ordovician of west-central Alaska. The species is among the oldest known carrier shell specimens, and also shows evidence of repaired shell breakage; the breakage may have been the result of unsuccessful predation attempts. The interior of the shell shows an unusual spiral groove and ridges that may have been associated with the animal's retractor muscle. This internal groove may be an overlooked feature of all species of Lytospira.

A new genus and species of Unionoidea, Tacuaremboia caorsii, are described from the Tacuarembó Formation (Upper Triassic–Upper Jurassic) of Uruguay. The genus is distinguished from other Unionoidea by its large size, thickness, edentulous hingeline, and the presence of claustra. It has some similarities with the Anodontinae and the Archanodontacea, but it cannot be assigned to any of the known family units.

Four new venerid species from the Cretaceous of the North American Pacific Slope are described and four previously described species are reassigned. Of the new species, two are allotted to new genera: Rhaiphiale based upon Rhaiphiale pharota n. sp. and Egrona based upon Egrona fallax n. sp., both Turonian in age and from southern California. The other new species are Loxo quintense n. sp., of late Maastrichtian age from California, and Paraesa cedrina n. sp., late Albian in age from Baja California, Mexico. The previously described species “Meretrix” arata Gabb, 1864, Turonian, and “?Meretrix” fragilis Gabb, 1869, late Maastrichtian, are placed in the new genus Callistalox; “Meretrix” lens (Gabb, 1864), Campanian age, and Flaventia zeta Popenoe, 1937, Turonian, are provisionally assigned to Paraesa Casey, 1952. This is the first identification of Paraesa from the Pacific Slope of North America. No species of Flaventia Jukes-Brown, 1908, is now known in Pacific Slope faunas.

The aquatic molluscan fauna of the late Oligocene–early Miocene Cabbage Patch beds of western Montana includes eight taxa, six of which are new at specific or subspecific level, Sphaerium bakeri, Valvata paula, Planorbula powelli, Biomphalaria haydeni, Lymnaea tumere, and Lymnaea vetusta ambigua. Two are referred to previously known taxa, Viviparus nanus and Lymnaea shumardi. The genera Biomphalaria, Planorbula, and Viviparus no longer occur in western Montana, nor in the Columbia River drainage. Planorbula powelli is the earliest unequivocal Planorbula from North America. Of the 18 supraspecific taxa of this molluscan fauna, eight (44%) are now displaced, all but one to the east and/or south. Climatic interpretations derived from modern habitats of the genera Biomphalaria and Polygyroidea suggest a late Oligocene–early Miocene Mean Annual Temperature of 10°C, with January means not less than 5°C, and July means about 15°C. Environmental analysis suggests a subhumid to subarid shrub and grassland vegetation similar to modern environments with > 50 cm Mean Annual Precipitation, surrounding marshy shallow lakes subject to seasonal desiccation. Effective moisture varied from slightly greater than the present for the late Oligocene to a latest Oligocene pluvial interval followed by subarid conditions for the early Miocene. Geographically, the drainage of this area was into a closed and isolated basin during the late Oligocene–early Miocene. Molluscan assemblages are found to support the tripartite division of the Cabbage Patch beds that has been based on mammals and should be useful in correlation between basins.

Reticuloceras (Swintoceras) n. subgen. unites an early group of the mid-Carboniferous goniatite family Reticulocertidae, in which reticulate sculpture is weakly developed or lacking and the typically reticuloceratid suture has slightly expanded ventral prongs. The type species, Reticuloceras (S.) spiraloides (Bisat and Hudson, 1943), is a rare, poorly known species from the British Namurian. Two additional species, R. (S.) wainwrighti (Quinn, 1966) and R. (S.) tiro (Gordon, 1969), are common in the basal type Morrowan Series, Lower Pennsylvanian, of Arkansas. Swintoceras occurs with two distinctive, late forms of the ammonoid, Hudsonoceras: Hd. ornatum (Foord and Crick, 1897) in Britain and Hd. moorei Quinn and Saunders, 1968, in Arkansas. The cooccurrence of these taxa correlates the basal Morrowan in its type region with the Namurian Reticuloceras nodosum (R1b) Zone of Britain and thereby also dates the close of the Mid-Carboniferous Eustatic Event in the North American Midcontinent.

The ecdysial style of Flexicalymene meeki (Foerste) from the Upper Ordovician of the Cincinnati arch (Ohio) is best characterized by a spectrum of configurations. Recurring patterns of displaced tergites and points of disarticulation indicate differential susceptibility of the exoskeleton to disarticulation during ecdysis. Specimens identified as exuviae are characterized by one or more of the following: thoracic segments displaced (unevenly spaced, disarticulated or telescoped); pygidia and/or cephala rotated away from the sagittal line; cephalon sharply bent ventrally at first thoracic segment; librigenae separated or folded ventrally along facial sutures; “extra” tergites (exuvia) superposed on the new exoskeleton; and missing elements, especially librigenae and hypostomae. The range of exuvial configurations suggests a variety of ecdysial behavior in this trilobite.

Specimens of the ostracode species Puriana pacifica Benson, 1959, from a modern assemblage from the Gulf of California can be sorted by visual inspection into five groups based on taphonomic condition. Characteristics used for sorting include: presence or absence of appendages; color and opacity of the valves; and evidence of abrasion, fragmentation, and boring. As measured by resistance to crushing force, members of the five groups show appreciable, progressive, postmortem weakening so that specimens in the poorest apparent condition are the weakest mechanically. The groups also differ in style of fracturing in response to crushing force. Fractures of valves of the freshest specimens are located quite consistently. Among specimens with progressively more damage, the location of fractures becomes less predictable. On valves of the most damaged specimens, typical fractures are short and likely to occur almost anywhere on the valve. These experimental results emphasize the importance of rapid burial in enhancing the likelihood of fossilization. Furthermore, they cast doubt on the ability of paleoecologists to use valves and carapaces of fossil ostracodes to interpret levels of wave and current energy in ancient environments because taphonomic weakening and subsequent destruction may effectively mask functional morphology.

In situ colonies of Bulmanicrusta? sp. encrusting the surface of a hardground from the Upper Ordovician Bull Fork Formation provide the first glimpse of the full colony form, habitat, and faunal associates of a crustoid graptolite. Bulmanicrusta? sp. exhibits a runner-type colony form suited to rapid expansion over hard substrates, indicating it was an opportunistic member of the hardground community. This community also included two bryozoans (“Proboscina” and Amplexopora), Cornulites, and crinoids. The Bulmanicrusta? sp. specimens contain numerous graptoblasts (small, thick-walled vesicles) in organic connection with the colony. These objects are located at branch termini and confirm that graptoblasts were not pathological features, but probably were resting cysts produced by the crustoid colony as a normal part of its life cycle. Thus, the presence of graptoblasts supports the interpretation that the Caesar Creek crustoid was adapted to ephemeral or disturbance-prone environments.

A unique monospecific bonebed of rhinophrynid anurans was recently discovered in the Wagon Bed Formation (Middle Eocene, Uintan), Hot Springs County, Wyoming. The bonebed occurs on a single bedding plane within a thin sandstone layer. This unit is part of a nearshore facies of a calcium carbonate-rich lake in which the water was warm, shallow, and quiet at the site of the mortality layer.

A representative area of this bonebed, approximately 450 square centimeters in size, provides the basis for this taphonomic and paleoecologic study. This area contains approximately 600 bones and at least 19 individuals are represented. Skeletons are nearly completely disarticulated but somewhat associated, bone modification features are absent, a slight preferred orientation of the linear bones is present, and many of the lighter, less dense skeletal elements are underrepresented. Scavengers probably contributed to disarticulation of the skeletons. Bone depletion occurred by a combination of the action of scavengers, weak currents, and the sloughing off of body parts as the carcasses floated. The assemblage was not subjected to extensive winnowing by currents.

All of the specimens within this assemblage represent young adults. Because the frogs are all of the same ontogenetic age and the deposit shows no signs of time averaging, the assemblage is interpreted as the result of catastrophic death, possibly by disease, of one age class. Either a population of frogs inhabited the site where the mortality layer formed or the carcasses floated into it.

A new specimen of the Cretaceous trionychoid turtle Basilemys praeclara Hay, from the Frenchman Formation (Upper Maastrichtian) of Saskatchewan, confirms the validity of the species, previously known only from the type specimen. Basilemys praeclara is considered the sister taxon of Basilemys sinuosa, and the restriction of this clade to the late Maastrichtian reinforces the distinctiveness of the Lancian chelonian fauna from the older Judithian chelonian fauna. Basilemys, Nanhsiungchelys, and Zangerlia comprise the family Nanhsiungchelyidae, with Basilemys and Nanhsiungchelys being sister taxa within the family.

The Mammalia from the Calf Creek Local Fauna, Cypress Hills Formation, Saskatchewan, include various Carnivora (197 specimens) and Creodonta (nine specimens). Most specimens are isolated teeth. The fauna includes Daphoenus sp., Daphoenocyon dodgei, daphoenine sp., Parictis parvus, Parictis sp., nimravid spp., Hesperocyon gregarius, Hemipsalodon grandis, Hyaenodon horridus, H. microdon, Hyaenodon spp., and indeterminate taxa. Most of the large number of deciduous teeth are referred to Hesperocyon or the Daphoeninae. Daphoenus canadensis, Russell, 1934, is a junior synonym of Daphoenocyon dodgei. Upper molars are tentatively referred to P. parvus; the geographic range of P. parvus is extended to include Saskatchewan and Wyoming. The Calf Creek Hesperocyon closely resembles samples of the genus from Pipestone Springs Local Fauna, Montana, and most levels at Flagstaff Rim, Wyoming. Most of the previously described Carnivora and Creodonta from Cypress Hills localities can be referred to species that occur in the Calf Creek Local Fauna. The Carnivora and Creodonta are consistent with an early to medial Chadronian age for this local fauna and suggest a relatively early age within that interval.

Three species of Yoderimyinae (Eomyidae: Rodentia) are recognized from the lower part of the White River Formation (early to medial Chadronian) in the Flagstaff Rim area, Wyoming. The new material allows an improved diagnosis for the subfamily. The enamel microstructure of Yoderimyinae supports its inclusion in the Eomyidae.

A new genus, Zemiodontomys, is established for Yoderimys burkei Black, and new material, including upper dentition, is referred to this species. This genus differs from Yoderimys in having higher crowned and more lophodont teeth and in lacking P3. A second new genus, Litoyoderimys, is established for Yoderimys lustrorum Wood, and a new species, L. auogoleus, is referred to the genus. This genus has lower crowned, more cuspate teeth than Yoderimys.

Through early and medial Chadronian time, evolution in yoderimyines includes the following morphologic transformations: increase in size; increase in crown height and lophodonty of cheek teeth; reduction of P3 (from double-rooted, to single-rooted, to absent); increase in relative size of P4 and p4; and increased longitudinal torsion of the mandible.

Disarticulated elements from three individuals of Mammuthus cf. M. columbi (Falconer) and one individual of Bison cf. B. latifrons (Harlan) were recovered from an excavation in gravelly, sandy clay of the Colma Formation at the southeast base of Telegraph Hill, San Francisco, California. This is the most abundant collection of late Pleistocene terrestrial vertebrates reported from San Francisco, and only the fourth record from excavations in the city proper. The Mammuthus-Bison association indicates a Rancholabrean age, and elements of these two taxa from this site have been radiocarbon dated at 25,380 ± 1,100 years B.P. Geologic setting, lithology, associated diatoms and pollen, and preservation of the bones suggest that these animals were buried rapidly in a boggy environment on the west margin of the broad valley now occupied by San Francisco Bay.

Paleozoic corals are very rare in rocky shore settings. The only Paleozoic encrusting coral so far reported from this environment is Favosites sp. from Ordovician rocky shore deposits in Manitoba, Canada (Johnson and Baarli, 1987). Reading and Poole (1961) reported corals and brachiopods that occur between, and “coating,” boulders from a Silurian rocky shore in England, but it appears that the corals and brachiopods only occur in the sediment enveloping the boulders, not as encrusters on the surfaces of the boulders. One reason for the sparse record of Paleozoic corals in rocky shore settings is the scarcity of described Paleozoic rocky shore deposits themselves. Johnson (1988) found only 20 examples of Paleozoic rocky shores in a compilation of references on ancient rocky shores from the literature. The paucity of described ancient rocky shores has been attributed to the prevalence in the past of epicontinental seas with little relief upon which to develop rocky shores and with higher wave attenuation farther from shore (Boucot, 1981; Harland and Pickerill, 1984). Johnson (1988) concluded that the major reason for the rarity of ancient rocky shores in the literature is the difficulty with which they are recognized and studied, owing to the relatively poor exposure of most unconformity surfaces. The rocky shore environment was also probably hostile to many Paleozoic coral genera. Recent scleractinian corals may serve as analogues because they are also not very abundant in rocky shore settings despite their great abundance in similar shallow-water, high-wave-energy reefal environments. Turbidity and relative substrate stability may be important limiting factors for corals in rocky shore environments. Many corals are known to be highly sensitive to sediment in the water column. Substrate stability (Wilson, 1987) and the scouring effects of sand in high-energy environments (Palmer and Palmer, 1977) also have been shown to affect the abundance and diversity of organisms encrusting cobbles and boulders.