The new species Cyathophycus pseudoreticulatus and a fragment of Cyathophycus reticulatus? Walcott, 1879, are described and reported from the lower part of the Upper Member of the Vinini Formation from black shale of late Whiterockian age. The sponges were collected from the north fork of Vinini Creek, in the north-central part of the Roberts Mountains, Eureka County, Nevada.

The calcareous skeletons of 17 species of Triassic demosponges from the northeastern Dolomites have been analyzed for microstructure and diagenesis. The four microstructures recognized (irregular, spherulitic, penicillate aragonitic, and homogeneous granular Mg calcite) are described in terms of mineralogy; shape, dimension, and arrangement of microstructural elements; mode of growth; and possible biomineralization. The diagenesis in these sponge carbonate skeletons is of an aggrading type that occurred in diagenetic units, semi-closed systems, delineated by organic phragmas, which controlled the flux of diagenetic fluids. We tentatively interpret these phragmas as the remains of water-insoluble macromolecules for space delineation during the biomineralization process. In the aragonitic skeletons the preservation grade is correlated with Sr content, and the replacement of aragonite by calcite is marked by a Sr value around 4,000 p.p.m. Calcitized aragonite still retains a detectable amount of Sr. In Mg calcite skeletons the continuous and regular increase of grain size is inversely correlated with Mg content and directly with the distance from the organic phragmas.

A gastropod assemblage is described from the middle Lower Devonian (Pragian) of Alai Ridge, Kyrgyzstan. It includes eight species, six of which are new. Two new genera are established, Alaionema and Barroisocaulus. Newly named species belonging to the above genera include: Alaionema kyrgyzensis and Barroisocaulus oliveri. In addition, four new species belonging to extant genera are also described: Omphalocirrus kaukensis, Ruedemannia tienshanica, Oriostoma sarydalchaensis, and Goniasma? asiatica.

Damage displayed by 18 of 954 relatively mature (> 35 mm diameter) specimens of Gonioloboceras goniolobum (Meek) from North American Midcontinent Upper Carboniferous sediments is interpreted to be bite marks caused by condrichthyans and other fish, particularly the symmoriid shark Symmorium reniforme. It is likely that these and other predators regularly preyed on Gonioloboceras goniolobum because all of the analyzed specimens of Gonioloboceras exhibit some evidence of unrepaired damage, including broached camerae and missing body chambers. Two new characteristics utilized with caution to detect predatory events on ammonoids are raised oval or circular pedestals on internal molds and the breakage and termination of septa in conjunction with a broken external shell. When sufficient damage to the Gonioloboceras conchs occurred during predatory attacks, the broached camerae flooded, the conch became negatively buoyant, and it sank in the vicinity of the attack. When preserved, these conchs form a variable component of an autochthonous fossil accumulation that can include numerous other cephalopod taxa, which also were probably subjected to predatory attacks. Other, but not all, ammonoid accumulations in the fossil record form similar autochthonous deposits, or even autochthonous portions of mixed deposits.

New Middle Cambrian fossils demonstrate unusual tagmosis within the Arthropoda. Rare specimens from the Spence Shale of northern Utah are assigned to Meristosoma paradoxum n. gen. and sp. One specimen from the Marjum Formation of west-central Utah is assigned to Meristosoma sp. These taxa are further assigned to the new family Meristosomatidae. Meristosoma, which reached 17 cm in length, is characterized by a short anterior shield, a long thorax with 36 or more articulating segments, and a posterior shield with as many as 11 fused segments. Its short anterior shield and long, multisegmented thorax have a myriapodan aspect, but Meristosoma differs from all myriapods by its posterior tagmosis. In dorsal view, its posterior shield is most like that of some macropygous trilobites, but Meristosoma differs from all trilobites by having a shorter anterior shield, ringed thoracic segments without trilobation, and no ventral doublure. Phylogenetic analysis indicates that Meristosoma is a primitive and basal arthropod. A more precise taxonomic assignment is hampered by a lack of information about its limb morphology.

Previously undescribed Holmiidae from the Sectigena Zone of Morocco indicate correlation of this zone with other zones bearing Holmiidae on Baltica, Avalonia, Siberia, and Laurentia. The occurrence of the youngest Antatlasiinae in the Sectigena Zone and the oldest Protoleninae in the overlying Hupeolenus Zone suggests correlations of the Sectigena Zone with upper Atdabanian beds bearing the youngest Antatlasiinae and the Hupeolenus Zone with Botomian beds bearing the oldest Protoleninae in Siberia. The occurrence, in the overlying Hupeolenus and Cephalopyge Zones, of Paradoxides s.l. in association with the olenelloid Cambropallas and with trilobites characteristic of the Lower Cambrian “Protolenus” Zone of Avalonia calls into question the major criteria for recognition of strata of Early and Middle Cambrian age. New taxa include lyouella contracta n. gen. and sp. of the Holmiidae and Bondonella sdzuyi n. sp. of the Neltneriidae. The known species of Neltneria, N. jacqueti and N. termieri, are revised.

Lithostratigraphy and depositional and epeirogenic history of the upper Placentian Series (Cuslett-Fosters Point Formations of the Bonavista Group) and Branchian Series (Brigus Formation) are identical in the northern Antigonish Highlands; Cape Breton Island; and eastern Placentia Bay, southeastern Newfoundland. Preliminary evidence suggests that the lower Middle Cambrian is present in the field area. A unified, uppermost Precambrian–Lower Cambrian, formation- and member-level nomenclature is appropriate to Avalonian North America, and the stratigraphic nomenclature of southeastern Newfoundland is applied in northern mainland Nova Scotia.

Latest Placentian shoaling and deposition of a peritidal carbonate lithosome and unconformable onlap of the trilobite-bearing Branchian Series occurred in shallow Avalonian shale basins from eastern Massachusetts to central England.

Uppermost Placentian Series faunas are very diverse in the Fosters Point Formation. Limited similarities with the South Australian Lower Cambrian are indicated by the presence of Camenella sp. cf. C. reticulosa, Conotheca australiensis, and Hyptiotheca sp., but these forms do not contribute to highly resolved correlation.

Twenty-eight taxa are illustrated from the upper Placentian and Branchian Series. Caveacus rectus n. gen. and sp., a phosphatic problematicum, is limited to the upper Placentian Series. The oldest, skeletalized, macrophagous predators are the Pseudoconodontida and the later appearing Protoconodontida (n. orders). The Pseudoconodontida includes the Protohertzinacea n. superfamily and Strictocorniculacea n. superfamily (with the Rhombocorniculidae and Strictocorniculidae n. families). Strictocorniculum vanallerum n. gen. and sp. is described. The tommotiid family Sunnaginiidae emend. includes Eccentrotheca, Sunnaginia, Kulparina, and Jayceia deltiformis n. gen. and sp.

Iberonepa romerali n. gen. and sp. is the most abundant insect species found in Lower Cretaceous (Barremian) lithographic limestones at “Las Hoyas,” Spain. External features of this species indicate that it should be assigned to the family Belostomatidae, with a similarity to the species Stygeonepa foersteri Popov, 1971, which was found in the Upper Jurassic (Tithonian) lithographic limestones of Solnhofen. This article discusses the relation between these two species and subfamilies of the Recent Belostomatidae. The new “Las Hoyas” species is described from adult specimens and from molts of nymphs, these differing only slightly from one another. The abundant number of specimens and the generally exceptional preservation have allowed interpretation of its probable natatory behavior on the basis of the functional morphology of the insect's legs.

The cassiduloid echinoid Calilampas californiensis n. gen. and sp. is described from middle lower Eocene (“Capay Stage”) shallow-marine sandstones in both the middle part of the Bateque Formation, Baja California Sur, Mexico, and the lower part of the Llajas Formation, southern California. The new genus is tentatively placed in family Pliolampadidae. The cassiduloid Cassidulus ellipticus Kew, 1920, previously known only from the “Capay Stage” in California, is also present in “Capay Stage” shallow-marine sandstones of the Bateque Formation.

The Orthograptus quadrimucronatus species group currently comprises 22 taxa, which, with the exception of O. ruedemanni, are distinguished from other orthograptids by the presence of paired apertural spines on their thecae. A detailed morphometric analysis of this group indicates that these taxa comprise four basic morphotypes that actually represent only six distinct species: O. pageanus, O. quadrimucronatus, O. spinigerus, O. ruedemanni, O. eucharis, and O. rivai.

Specimens of Orthograptus pageanus have a rapidly widening rhabdosome with elongated spines on the first two or four thecae. Orthograptus pageanus is divided into two chronological subspecies, an older, smaller form, O. pageanus pageanus, and a younger, larger form, O. pageanus maximus n. subsp. Specimens of O. spinigerus have elongated spines on one or two thecal pairs between the sixth and thirteenth thecal pairs, a very narrow proximal end, and a rapidly widening rhabdosome. Specimens of O. quadrimucronatus have a more parallel-sided shape and no unusually long spines. The subspecies O. quadrimucronatus richmondensis is differentiated by the absence of both a median septum and a th 12 spine. Orthograptus ruedemanni, O. rivai, and O. eucharis are all dwarf forms.

Within a chronostratigraphic framework based on K-bentonite bed correlations the pattern and process of evolutionary change in the members of the O. quadrimucronatus species group is examined. Morphometrically, each species remains a coherent entity through time, occupying its own distinct morphospace. Each speciation event probably occurred rapidly, precluding the preservation of intermediates, and the new species retained their basic morphology throughout their existence. Within these lineages, phyletic changes were either absent or encompassed only changes in size, even when accumulated for much longer intervals than would be expected for speciation events. These patterns appear to be consistent with the evolutionary model of punctuated equilibrium.

Conodonts from two localities on the western shore of Alberto Island, southeastern Alaska, include Polygnathus alexanderensis n. sp., P. angustipennatus, P. borealis n. sp., P. praetrigonicus n. sp., P. robusticostatus, P. pseudofoliatus, P. linguiformis linguiformis gamma form of Bultynck, P. parawebbi beta form of Chatterton, P. angusticostatus, P. costatus costatus, Polygnathus sp. B of Savage, 1977, Tortodus kockelianus australis, and T. kockelianus kockelianus. The faunas are considered to be of middle to late Eifelian (kockelianus Zone) age. On Prince of Wales Island, just north of Staney Creek, exposures of Wadleigh Limestone include the conodonts Polygnathus trigonicus, P. kennettensis, P. alexanderensis, P. angustipennatus, P. parawebbi beta form, P. eiflius, P. linguiformis linguiformis gamma form, P. borealis, P. angusticostatus, P. robusticostatus, P. costatus costatus, P. pseudofoliatus, Tortodus kockelianus australis, and T. kockelianus kockelianus, also suggesting a middle to late Eifelian (kockelianus Zone) age. Conodonts from the west end of the easternmost of the Alberto Islands include Polygnathus linguiformis linguiformis gamma form, P. parawebbi beta form, P. xylus ensensis, and Ozarkodina brevis, indicating a late Eifelian to early Givetian (ensensis to varcus Zones) age. The presence of Polygnathus kennettensis, P. parawebbi beta form, and P. borealis suggests a biogeographic affinity with other parts of western North America during Eifelian time.

While studying X-ray films of new iniopterygians (Subterbranchialia, Chondrichthyes) in the Excello Shale from the Field Museum of Natural History's Bethel Quarry locality in southern Pike County, Indiana, a moderately dense spread of tiny cladodont shark denticles was noticed on the radiographs, confined to micro-horizons of shale about 7.5 mm thick, which also contained the iniopterygians.

These denticle spreads, which are entirely unrelated to the iniopterygians, but are seen on X-ray films of most of the chondrichthyan skeletons collected from a sheet of Excello Shale of about 500 m2 in extent, and mostly from two very fossiliferous levels, have an average density of about nine denticles per 1 cm2. Because the chondrichthyan skeletons were collected from all parts of the quarry, it is probable that the denticle spreads in several micro-horizons extended over the entire quarry area and perhaps beyond. The number of denticles in each of the micro-horizons in 500 m2 of shale thus amounts to about 4.6 million.

A discussion of the origin of these vast numbers of cladodont denticles, given a variety of taphonomic and depositional constraints, results in the conclusion that these large numbers of denticles could not have resulted from the two species of sharks, Denaea meccaensis and Stethacanthulus longipeniculus, that are members of the burial assemblage and bear dentition teeth indistinguishable from those in the areal spread. Evidence suggesting very rapid deposition of organic muds that produced the characteristic Mecca Quarry type carbonaceous, sheety shales rules out the possibility of accumulation of the denticle spreads over extended periods of time. Because sharks do not possess nearly enough dentition teeth to account for this occurrence, one must entertain the possibility that the denticles are not all dentition teeth, but perhaps for the most part mucous membrane (or even dermal) denticles, though none such are presently known to display cladodont design.

The Late Irvingtonian fauna of Port Kennedy Cave, Pennsylvania, includes four species of turtles. Terrapene carolina is the most common species; Clemmys insculpta is present. A nearly complete plastron of Emydoidea blandingii from Port Kennedy and two specimens from New Jersey sites indicate that the species ranged through the Delaware Valley region during much of the Quaternary. The type material of Clemmys percrassa Cope is reidentified as Geochelone (Hesperotestudo) percrassa Cope, and becomes one of the more northeasterly records of the genus in North America.

A statistical and morphological study of the pterosaur Rhamphorhynchus from the Solnhofen Limestone of Germany shows that specimens fall into discrete size-classes that are year-classes resulting from seasonal mortality or preservation of specimens. Taxonomic characters used in the past to separate species of Rhamphorhynchus are all related to size and ontogeny, and all specimens belong to a single species, R. muensteri. Thus, the collections of Rhamphorhynchus provide an unequaled record of the growth and development of a Jurassic rhamphorhynchoid pterosaur. Rhamphorhynchus did not have rapid determinate growth; the growth rate was comparable to that of extant crocodilians, and growth continued over the course of at least three years after individuals began to fly.

A new species of Megacerops, M. kuwagatarhinus, is described from deposits belonging to the White River Group in southeastern Montana. Megacerops kuwagatarhinus is distinguished from all other species of Megacerops by the peculiar morphology of the horns, which are bifurcated distally into two well-developed branches. Two specimens from the Hunter Quarry of Saskatchewan, Canada, also share this horn morphology and are referred to the species.