Angulichnus alternipes n. ichnogen. and n. ichnosp. is a distinctive epichnial trail from the heterolithic facies of the Middle Cambrian Bright Angel Shale at Horn Creek, Grand Canyon, Arizona. It consists of a central zig-zag furrow bordered by biserially opposed alternating tracks. Though clearly formed by a benthonic arthropod, the trail cannot be attributed to a trilobite and is therefore important as an indicator of the presence of nontrilobite arthropods in the Bright Angel Shale. It is suggested that an arthropod similar to Habelia optata from the Burgess Shale would be a convincing trail-former. Sedimentologic analysis indicates that the heterolithic facies represents storm-induced deposition of sand, followed by a low-energy period during which traces were formed as mud settled to the bottom.

The Sultan Formation is a Middle and Upper Devonian inner shelf carbonate sequence in southern Nevada containing four stromatoporoid-dominated biofacies. Reported herein is a study of the Ironside Dolomite and Valentine Limestone Members exposed at Mountain Springs, Nevada. Eight lithofacies are distinguished and interpreted as a transgressive sequence, with deposition ranging from the supratidal zone to just below wave base. Each of the biofacies is unique and confined to a specific depositional environment as interpreted from the lithofacies reconstructions. The purpose of the study was to gain a better understanding of the range of ecologic conditions—physical, chemical, and biological—to which these stromatoporoids were adapted.

Based on the research, it is concluded that stromatoporoids flourished in a variety of nonreef habitats which ranged from highly stressful peritidal environments where only stromatoporoids were accommodated to less stressful offshore habitats where other organisms may have been in direct competition. Although habitat generalists are usually poor competitors, these stromatoporoids appear to have been an exception. Their ability to colonize a variety of substrata, their broad tolerances to chemical conditions and circulation patterns, and their emphasis on high rates of lateral growth have permitted them to simultaneously occupy unstable tidal channel embayments and more benign offshore habitats.

The hermatypic scleractinian cryptic coral biota living under mobile rubble in the reef flat and back reef zones of a Fijian fringing reef was surveyed in detail in August of 1984; only 138 days later the reef was struck by the first of two sequential hurricanes (57 days apart). The same sample areas were re-studied in August 1985, thereby providing the first detailed census of pre- and post-hurricane cryptic reef coral populations, and allowing an assessment of hurricane impact on these populations.

The 61 cryptic species (60 corals and Millepora) show 88 percent commonality with the intertidal and shallow subtidal reef surface coral population (68 species), and therefore are a good representation of the surface biota.

A major effect of the hurricanes was a reduction of almost 50 percent in the number of boulders sheltering cryptic coral. However, among boulders that retained coral through the storms, there was only a 5 percent reduction in the mean number of corals per boulder, signifying that damage to the surviving population was minor. The composition of the surviving cryptic coral population is essentially unchanged from its pre-hurricane state (there are differences in absolute abundances), and the relative importance of the species does not show marked change in most cases. Coral morphologies show little change in their absolute and relative percent abundances after the hurricanes. In contrast to what is normally seen in reef surface habitats, therefore, coral colony form did not appear to be an important determinant in survivability for those living under boulders; primary selection by the storms seems to have been on boulder form rather than cryptic coral form.

Cryptic sub-rubble coral populations may function as a preserve for elements of the pre-hurricane reef surface community. For example, delicately-branching forms that are commonly devastated in reef surface habitats during hurricanes may, in some cases, be preserved in great numbers under boulders or in other cryptic habitats. This provides a “recruitment pool” that can greatly accelerate their recovery and re-establishment on the post-hurricane reef surface, and dampen the potentially severe community dislocations arising from intense competition for space in “instantaneous” new reef substrate.

West Falls Group strata (Chemung facies) of Upper Devonian (Frasnian) age in New York State reflect sedimentation on a storm dominated sandy shelf. Rugose corals occur in storm deposited coquinites rich in bioclastic debris and are abundant locally, although representing only three species, Tabulophyllum orientale (Stumm), Macgeea ponderosa Stumm, and Disphyllum caespitosum (Goldfuss). The Tabulophyllum and Macgeea species are both characterized by large amounts of stereome (biogenic calcite) in the apical part of the corallite, perhaps useful in stabilizing corallites in the sediment.

Specimens of a new species of the Permian waagenophyllid coral genus Waagenophyllum, W. klamathensis, have been recovered from limestone lenses near the top of the Upper Permian Dekkas Formation in the eastern Klamath Mountains, and similar specimens have been collected from an isolated limestone mass in the eastern Hayfork terrane of the southwestern Klamath Mountains, northern California. Another specimen of Waagenophyllum, which may represent another species, has been recovered from another limestone mass in the Hayfork terrane. These specimens of Waagenophyllum, a genus which otherwise is restricted to the Tethyan Province, provide the only tie between the Permian limestone masses of the eastern Hayfork terrane, which also contain typical Tethyan foraminifers, and the eastern Klamath Mountains terrane (McCloud belt), which contains many fossils with non-Tethyan affinities.

A detailed morphological study of over 2,500 Middle Ordovician (Black Riveran) lophospirid archaeogastropods from the lower half of the Platteville Formation (Pecatonica Member and Mifflin Submember of the McGregor Member), principally as it is exposed in southern Wisconsin, has permitted the definition of five species of Lophospira. Lophospira perangulata (Hall), L. milleri (Hall), L. serrulata (Salter), L. helicteres (Salter), and L. delicata (n. sp.) are preserved throughout a three-meter interval of fine-grained, heavily bioturbated carbonates, now dolomitized. Deposition took place on a broad, shallow tropical shelf, which was characterized by low rates of deposition and low physical energy. The sampled interval represents about 500,000 years. The benthic marine invertebrate fauna is well preserved, diverse, and characteristic of an environment of normal marine salinity.

Of the five Lophospira species, only one, L. perangulata, has been positively identified in older strata (late Whiterockian, eastern North America). The other four species were endemic to the interior seas, and apparently at least two of these, L. serrulata and L. helicteres, did not survive into post-Platteville (post-Black Riveran) environments. Changes in the proportions of lophospirid species from the Pecatonica into the Mifflin strata probably reflect subtle changes in the distribution of carbonate shelf habitats but no major alteration in the kinds of habitats available for colonization.

The presence of large numbers of phragmocones of Eutrephoceras and Aturia in an upper Eocene beach deposit of the La Meseta Formation on Seymour Island is the first known occurrence of beach-drifted accumulations of nautilid shells in the fossil record and may also represent the first documentation of a mass stranding of nautilids in the Cenozoic.

The fossilized gladii of six squid from the Pembina Member of the Pierre Shale (Upper Cretaceous, Campanian) of southern Manitoba are referred to Tusoteuthis longa Logan, 1898, a species previously reported only from the Niobrara Formation of Kansas. The characters used to identify the genus are reviewed and it is referred to the family Kelaenidae. Documentation of these specimens extends the range of both the genus and the family to the Campanian of Canada.

The Lower Cambrian sequence south of the town of Caborca in northwestern Sonora, Mexico, has yielded the trilobites Nevadia ovalis n. sp. and Judomia orbis n. sp., plus an incomplete fallotaspid cephalon. The Nevadella Zone of Fritz (1972) can now be recognized in the Puerto Blanco Formation, and fossils from the middle part of the formation strongly suggest the presence of the Fallotaspis Zone. The new fossils permit improved correlation of the Mexican sequence to sections in the United States and to Lower Cambrian stages of China and the Soviet Union.

Two recently collected specimens of Bogotacrinus scheibei Schmidt, 1937, from the Devonian (Emsian–Eifelian) Floresta Formation of Colombia reveal that Bogotacrinus is a dicyclic camerate crinoid genus closely related to Pterinocrinus Goldring, 1923 (Lower–Upper Devonian of eastern North America and western Europe), and Ampurocrinus McIntosh, 1981 (Lower Devonian of Bolivia). The new diplobathrid camerate crinoid family Pterinocrinidae, characterized by species with low conical dicyclic cups and rami composed of compound, bipinnulate brachials, is herein proposed to accommodate these three genera. This family originated in western Europe and migrated into the Malvinokaffric and southern Eastern Americas Realms during the Early Devonian and into the northeastern Appalachian Basin by the Late Devonian.

Conodont faunas recovered from the upper 80 m of Late Permian limestones on the Greek island of Hydra (Idhra) include Neogondolella leveni (Kozur, Mostler, and Pjatakova), Neogondolella orientalis (Barskov and Koroleva), Hindeodus julfensis Sweet, Xaniognathus hydraensis n. sp., and Ellisonia sp. The conodonts occur with a rich assemblage of silicified brachiopods, fusulines, and other invertebrates. Diagnostic fusulines include Reichelina media Miklukho-Maklai and Palaeofusulina cf. P. prisca Deprat. The conodont and fusuline faunas are correlative with well-known faunas described from the lower part of the Ali Bashi Formation of the Djulfa region of Iran, and with similar faunas described from other regions of Central Asia. The presence of conodonts from the Neogondolella orientalis Zone of Kozur indicates that the age of the upper part of the Permian sequence on Hydra is early-middle Dzhulfian (Baisalian Substage).

New records of Late Triassic reptiles from the Chinle Formation of Arizona include a new species of small trilophosaurid, a sphenodontid, and two taxa of eolacertilians. ?Trilophosaurus jacobsi n. sp. is a small trilophosaurid showing affinities to the type of Trilophosaurus buettneri of the southwestern United States and Variodens inopinatus from the Upper Triassic of Great Britain. A sphenodontid is also reported along with maxillae tentatively referred to the Kuehneosauridae and a jaw fragment from a subpleurodont eolacertilian with polycuspate teeth.

Tikisuchus romeri n. gen. and sp. is a rauisuchid thecodontian from the Late Triassic Tiki Formation of India and is the first rauisuchid material to be recorded from Asia. The skull is very large in relation to the presacral length and is equipped with sharp, serrated teeth. The astragalus has a very high dorsal process and the calcaneal tuber is short; the ankle joint is of “crocodile-normal” type.

The rauisuchids were the dominant terrestrial predators during the Triassic and shared similar ecological niches with the emerging theropods. The agility and superior locomotion of theropods may have contributed to their success and to their eventual replacement of the rauisuchids at the end of the Triassic.

The largest known member of the mammalian order Multituberculata is the taeniolabidid Taeniolabis, which is known from Puercan (early Paleocene) localities in northern New Mexico, Utah, Montana, and southern Saskatchewan. A locality in the Ludlow Formation of southeastern Montana has produced remains of a new species, T. lamberti n. sp., which is based on a well-preserved dentary with teeth. Isolated teeth from the Tullock Formation of northeastern Montana are referred to T. lamberti n. sp. and Taeniolabis sp.

Taeniolabis triserialis, known exclusively from the San Juan Basin, New Mexico, is shown to be a junior synonym of T. taoensis. Taeniolabis sulcatus, the type species of the genus, is recognized as a nomen dubium and is synonymized with T. taoensis based on general morphology and occurrence in the same stratigraphic unit and collecting area (lower part of the Nacimiento Formation, San Juan Basin, New Mexico). The name T. taoensis is retained for this taxon in the interest of nomenclatorial stability. These synonymies limit to one the number of species of Taeniolabis recognized in the San Juan Basin, New Mexico. It is proposed that T. taoensis be designated the new type species of the genus Taeniolabis.

Three successive species of Neohipparion are recognized from the Gulf Coastal Plain: N. affine from the early Clarendonian Lapara Creek Fauna of Texas; N. trampasense from the very late Clarendonian and early Hemphillian of Florida; and N. eurystyle from the late early and late Hemphillian of Florida. Numerous specimens from the Love Site, Alachua County, Florida, as well as from other faunas of similar age from Florida, Kansas, and Nebraska (e.g., the Xmas-Kat Quarries), are referred to N. trampasense. This species is ancestral to all later species of Neohipparion, as it shares with them many advanced dental characters, but often in a rudimentary or intermediate form. Five valid species constitute the monophyletic genus Neohipparion, which ranges from the late Barstovian to the latest Hemphillian (late Miocene through earliest Pliocene) in North America. A close phylogenetic relationship between Neohipparion and “Merychippus” republicanus and/or Pseudhipparion is proposed based on similarities of cranial and dental features.

A partial cranium and axial skeleton of an individual Symbos cavifrons were excavated in 1983 from the Mesa Verde Loess on Grass Mesa, Montezuma County, Colorado. Parts of at least 24 bones were recovered, including the first complete set of cervical vertebrae known for Symbos cavifrons. This individual, radiocarbon dated at 15,970 ± 155 yr B.P. (SI-6137), contributes to the definition of the southwestern edge of the range of the species and provides new information about the nature of the vertebral column. Pathologic constriction of the transverse canals is evident in the third and seventh cervical vertebrae. The pattern of bone distribution suggests that carnivores consumed part of this animal. The radiocarbon date also establishes the last major episode of loess deposition in the Four Corners region of the southwestern United States.