Mandalacystis dockeryi n. gen. and sp. is known from seven complete or nearly complete thecae, six partial thecae, and numerous separate plates from the Oil Creek Formation in south-central Oklahoma, and a single thecal plate from the Antelope Valley Limestone in Nevada. Details of skeletal microstructure (stereom) are well preserved, permitting scanning electron microscopy for the first time in the Eocrinoidea, and demonstrating that plate thickness on thecal faces is only 60–70 μm. Mandalacystis is characterized by labyrinthine ridges on both faces of the theca, relatively short brachioles, and a normal stem with holdfast (at least in juvenile stages). Based on the normal biserial arrangement of brachiolar plates in the brachioles and the possession of a normal stem, Mandalacystis appears to be one of the most primitive rhipidocystids, closely related to Petalocystites.

Mandalacystis dockeryi lived in a storm-dominated, shallow-water offshore habitat on patches of skeletal debris surrounded by soft, terrigenous mud. This setting may have been conducive to the transition from an erect, attached mode of life to the prone, unattached lifestyle of later rhipidocystids.

A single phyllodont tooth plate was identified in core from the Permian San Andres Formation of the Palo Duro Basin, Texas Panhandle. This is the first vertebrate fossil recorded from the San Andres Formation, and extends the Permian range of phyllodont dentitions into the lower Guadalupian Stage. The life environment is inferred to have been normal marine to marginally hypersaline, based on the occurrence of the specimen near the top of a carbonate unit in a carbonate-evaporite cycle.

Brachylepas americana n. sp. is described from abundant and well-preserved capitular and basal whorl plates from a littoral facies in the basal part of an Upper Cretaceous (upper Campanian) conglomerate questionably assigned to the Brownstown Formation in Hot Spring County, Arkansas. The new species resembles the European littoral Campanian–Maastrichtian species B. guascoi (Bosquet), and differs markedly from the only other known American species, B. angulosa Collins, from the Upper Cretaceous middle Ripley Formation of Mississippi. A few juvenile carinae of Virgiscalpellum may represent V. gabbi apertus Collins, previously known from the Ripley and basal Prairie Bluff Formations in Mississippi.

Eight of the crinoids described by Rowley (1904) are redescribed and reclassified. This material is from northeastern and southeastern Missouri and was believed to include both Early Silurian and Middle Silurian material (Rowley, 1904). Reconsideration of this material changes considerably the interpretation of these fossils. All are assigned to a different genus with some assigned to a different order or subclass. Also, age assignments are clarified. Crinoids studied here that are considered to be probably Late Ordovician rather than Early Silurian are Calceocrinus alleni (previously Deltacrinus alleni), Ptychocrinus insperatus (previously Abludoglyptocrinus insperatus, Glyptocrinus insperatus, and G. insperatus var. carinatus of Rowley, 1904), Ptychocrinus pentagonus (previously Glyptocrinus insperatus var. pentagonus), Gnorimocrinus? problematicus (previously Gissocrinus? problematicus), and Glyptocrinidae genus unknown (previously Lampterocrinus? comptus). Two Middle Silurian (lower Ludlovian) crinoids that were described by Rowley are restudied, Thalamocrinus ovalis (previously Cyathocrinus? ovalis) and Clematocrinus dubius (previously Cordylocrinus? dubius).

An extinct ictalurid catfish, Ictalurus spodius n. sp., is described from the Pleistocene of Central Mexico. It shares derived osteological characters with the subgenus Ictalurus and the I. punctatus species group. The new species is known from middle Pleistocene fluvial and lacustrine sediments and was abundant until near the end of the Pleistocene when it was replaced by a closely related species, I. dugesi. The latter is known from late and post-Pleistocene lake-bottom deposits and is widespread in Central Mexico today.

The well-exposed and fossiliferous Permian carbonates in China have yielded Early and Late Permian species of the Sweetognathus complex that permit worldwide stratigraphic evaluation of members of the group. The sporadic appearance of species of Sweetognathus and related genera throughout the Permian in western North America and Iran, in particular, may represent iterative evolution and homeomorphy. The pectiniform element morphologies of the several species are interpreted as most important for evolutionary studies and document a partial Permian biostratigraphy in China that aids in the interpretation of less complete sequences elsewhere. A new genus, Pseudosweetognathus, and four new species, Pseudosweetognathus costatus, Sweetognathus subsymmetricus, S. paraguizhouensis, and Iranognathus nudus, are described.

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).

A method has been developed that uses holographic interferometry to generate contour maps of the occlusional surfaces of fossil teeth. The resulting contour map is, in itself, a valuable descriptive tool. In addition, it provides information for a very large data base, which has been used in trend-surface analysis and Q-mode clustering. As an example, these analytical techniques are applied to a set of Pliocene badger teeth. The same methods can be applied to any paleontological problem dealing with shapes of small objects.

Jujuyaspis borealis is reported from earliest Ordovician (North American usage) limestones in central Texas and western Utah, the first time this species has been recognized in the United States. Jujuyaspis is a widespread olenid trilobite that occurs near the base of the Tremadoc Series in a variety of lithologies in North and South America, Europe, and Asia. When international agreement is reached on the exact horizon at or near the base of the Tremadoc Series that is to be used as the Cambrian–Ordovician boundary, Jujuyaspis will likely prove to be a very useful taxon for recognition of the boundary interval.

Additional fossil material from the Valentine Formation in Knox and Brown Counties, Nebraska, has allowed for the recognition of three new species of rodents, a heteromyid (Perognathus brevidens), a geomyid (Parapliosaccomys annae), and a zapodid (Schaubeumys cartomylos). The specimens referred here to P. brevidens were previously identified as P. furlongi, those of S. cartomylos were identified as S. grangeri, and those of P. annae were previously recognized as Lignimus cf. L. hibbardi. It is evident that Lignimus Storer should be restricted to the type species L. montis, and the remainder of the species referred to this genus are referred to Parapliosaccomys Shotwell. Parapliosaccomys is recognized as the earliest member of the subfamily Geomyinae based on its dental morphology, which extends the range of this subfamily into the Barstovian. The fauna from Annie's Geese Cross Quarry (Knox County) is recognized as being late Barstovian based on comparison with the older Norden Bridge Quarry (Brown County).

The genus and species Johnognathus huddlei Mashkova, 1977, is synonymized with Distomodus staurognathoides (Walliser, 1964) on the basis of common occurrence, similar morphology, and the discovery of a complete S element of D. staurognathoides with a posterior process developed into a platform that is identical in morphology to specimens referred to J. huddlei.

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.

Additional information on the alleged gastroliths in Early Cretaceous formations of the Western Interior has changed the writer's opinion from skepticism about a dinosaur causative agency to belief that it is a valid explanation. Concentrations of exotic rounded and polished stones have been found in close association with a number of skeletons. Aside from this, the best evidence is distribution of individual stones in environments where inorganic agencies seem improbable; distinctive individual stones have apparently been carried hundreds of kilometers. Gastroliths have value as quasi-guide fossils. From geographic and geologic associations it is suggested that various sauropods and perhaps the contemporary ornithopod, Tenontosaurus tilleti, were the chief stoneswallowers of the Early Cretaceous of the Western Interior.

Four species of rhinoceros occur together in the Barstovian (middle Miocene) faunas of southeast Texas, a unique situation in the Miocene of North America. Two are assigned to normal contemporary High Plains species of Aphelops and Teleoceras, and two to dwarf species of Peraceras and Teleoceras. The dwarf Peraceras is a new species, P. hessei. The dwarf Teleoceras is assigned to Leidy's (1865) species “Rhinoceros” meridianus, previously referred to Aphelops. “Aphelops” profectus is here reassigned to Peraceras.

The late Arikareean (early Miocene) Derrick Farm rhino, erroneously referred to “Caenopus premitis” by Wood and Wood (1937), is here referred to Menoceras arikarense. Menoceras barbouri is reported from the early Hemingfordian (early Miocene) Garvin Gully local fauna of southeast Texas. The rhinos from the early Clarendonian Lapara Creek Fauna are tentatively referred to Teleoceras cf. major.

The three common genera of middle late Miocene rhinoceroses of North America (Aphelops, Peraceras, Teleoceras) are rediagnosed. Aphelops and Peraceras are more closely related to the Eurasian Aceratherium and Chilotherium (all four together forming the Aceratheriinae) than they are to the American Teleoceras. Contrary to Heissig (1973), Teleoceras is more closely related to the living rhinoceroses and their kin (together forming the Rhinocerotini) than it is to the Aceratheriinae.

This paper presents a morphometric study of the conodont genus Ancyrodelloides. It is one of a series of such papers whose goal is to increase the precision of correlation within the Lower Devonian by refining the taxonomic basis of its biostratigraphic units. Ancyrodelloides species are confined to the delta Zone and may be used to divide it into three parts. Morphometrics verify the species rank of A. eleanorae, A. limbacarinatus, A. trigonicus, and A. transitans. Ancyrodelloides delta and A. omus are retained as species on qualitative grounds, but need larger samples for statistical evaluation. Ancyrodelloides asymmetricus and A. kutscheri are classified as varieties, but lack adequate samples.

Systematically diverse assemblages of fossil plants have been collected in late Miocene strata at seven sites in northern Antelope County, Nebraska. Fossils were found in several members of the Valentine and Ash Hollow Formations of late Barstovian to medial Clarendonian (13–10 MYBP) age and unnamed members of the Ash Hollow Formation of late Clarendonian to early Hemphillian (9.5–8.0 MYBP) age. Seeds, fruits, and leaf-sheath fragments of 18 species from the families Equisetaceae, Cyperaceae, Gramineae, Boraginaceae, Juglandaceae, and Ulmaceae are described. These occurrences represent a 200 mile (322 km) eastward extension of the known geographic range of all of the taxa during the Miocene. The occurrence of Juglandaceae is the first reported from widespread Miocene strata of the Ogallala Group in central North America.

New flexible crinoids referable to Taxocrinus Phillips and Onychocrinus Lyon and Casseday are made known from Carboniferous (Mississippian, Chesterian) strata of Tennessee. Taxocrinus strimplei n. sp. and Onychocrinus sp. A are reported from a single locality in the Bangor Limestone in Cumberland County, east-central Tennessee. Specimens of both species are characterized by having fewer numbers of brachials than any species yet referred to either genus. Both the evolutionary development of their brachial series and their stratigraphic position suggest that these species are at or near the end of lineages of these two genera.

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.