Discovery of fossils of the Ediacara biota near the top of the Spitzkopf Member at farm Swartpunt extends the known range of these remains in Namibia more than 600 m to near the sub-Cambrian unconformity. The fossiliferous beds occur approximately 100 m above a volcanic ash dated at 543 ± 1 Ma, and thus may be the youngest Proterozoic Ediacara-type fossils reported anywhere in the world. Fossils are preserved within and on the tops of dm-thick beds of storm-deposited sandstone at two stratigraphic levels; the environment is interpreted as open marine, generally calm but with episodic disruptions by storm waves, and probably within the euphotic zone. The presence of Pteridinium carolinaense (St. Jean), which is also known from the classic sections in Ediacara and the White Sea among others, reinforces evidence from geochronology and chemostratigraphy that the Swartpunt section is terminal Neoproterozoic in age. The new genus and species Swartpuntia germsi is a large, multifoliate frond that exhibits at least three quilted petaloids. Macroscopically, Swartpuntia resembles Pteridinium and Ediacara-type fronds such as Charniodiscus traditionally interpreted as Cnidaria, whereas microscopically it exhibits segmentation that is remarkably similar to that of the putative worm Dickinsonia. Combination of diagnostic characters of these supposedly disparate groups in a single species suggests that many species of quilted Ediacaran organisms were more similar to each other than they were to any modern groups, and provides support for the concept of the “Vendobionta” as a late Neoproterozoic group of mainly multifoliate organisms with a distinctive quilted segmentation.

Mobergellans are a distinctive group of Lower Cambrian breviconic shells with a prominent set of internal scars, presumably representing sites of former muscle attachment. Shells grew by accretion and appear to have secreted primary phosphate. Here a redescription is given of mobergellans, assigned to Hippoklosma new genus, from the Khairkhan Formation (Botomian-age equivalent) of southwest Mongolia. Hippoklosma mongolica (Missarzhevsky) is bilaterally symmetrical, with five pairs of radiating structures. These are presumably homologous with the muscle scars of other mobergellans, but in contrast consist of a series of disks (herein fibroplacodes) each containing a characteristic fibrous structure capped externally by a smooth lid. The apical region of the shell is domelike with transverse segmentation. A review of other mobergellans, including new data on Mobergella holsti from Sweden and Discinella micans from New York, and possibly related taxa concludes that although their affinities are problematic, a relationship with the Mollusca may be the most plausible hypothesis on existing evidence.

Two samples from a large, allochthonous limestone block in the McHugh Complex of the Chugach terrane on the Kenai Peninsula, Alaska, contain species of 12 genera of Permian Fusulinina including Abadehella, Kahlerina, Pseudokahlerina?, Nankinella, Codonofusiella, Dunbarula, Parafusulina?, Chusenella, Verbeekina, Pseudodoliolina, Metadoliolina?, Sumatrina?, and Yabeina, as well as several other foraminiferans and one alga. The assemblage of fusulinids is characteristically Tethyan, belonging to the Yabeina archaica zone of early Midian (late Wordian) age. Similar faunas are known from the Pamirs, Transcaucasia, and Japan, as well as from allochthonous terranes in British Columbia, northwestern Washington, and Koryakia in eastern Siberia.

A single specimen of Hazelia palmata Walcott, 1920, was collected from the Middle Cambrian Marjum Formation near Marjum Pass, in the central House Range, western Utah. This is a first occurrence of the species outside the Burgess shale region of British Columbia, Canada. The flattened oval impression of the monaxonid demosponge shows characteristic tufts and spicule structures of the species.

Shell structure has been studied in two species of the family Craniidae Menke, 1828, from the Upper Jurassic of East Ukraine and from the Lower Cretaceous of Crimea, South Ukraine. These species belong to the new genus Mesocrania—M. barskovi (Smirnova, 1972) and M. condylata new species. A layer of coarse regular rhomboidal crystallites was discovered between the primary layer of acicular crystallites and the secondary laminar layer. Branching punctae canals were observed in M. barskovi.

Repaired shell injuries are reported in 11 specimens including six genera and eight species of gastropods from the upper Middle Ordovician (Caradoc) Kullsberg Limestone and the Upper Ordovician (Ashgill) Boda Limestone, Siljan district, Sweden. The specimens are of different sizes and morphologies, including one isostrophic, three low-spired, and six moderately high-spired turbinate forms. Single and repeated episodes of shell damage and subsequent repair are preserved, the breaks ranging from simple arcuate or scalloped fractures to removal of large sections of the apertural margin. Both early and late growth stages show damage, but the injuries are usually restricted to only one whorl. No shell repairs were discovered on the 65 more or less complete specimens of the subulitids, although the smooth shell makes observation difficult. Injuries in the Siljan samples are found in both microgastropods and large specimens, but the sample is too small for meaningful quantification. The shell repair frequency is about 7 percent, based on examination of 404 specimens (54 from Kullsberg Limestone and 350 from Boda Limestone). Most of the repaired injuries are attributed to failed predation, adding significantly to the Lower Paleozoic documentation of predation on gastropods. The gastropod shells are morphologically weak by modern standards, but do show some architectural strengthening features such as narrow apertures, collabral or spiral threads, and other ornamentation. The identity of the predator(s) is unknown.

Extensive collections of Pennsylvanian marine gastropods from 20 marine units in the Appalachian Basin contain 227 recognizable taxa. Twenty-two new species and subspecies are recognized including Bellerophon (Bellerophon) laticallis, B. (B.) graphicus varicallis, B. (Pharkidonotus) breyeri, Knightites (Cymatospira) montfortianus discordis, K. (Retispira) fascireticulatus, Colpites lirata, Abylea formosa, A. paradoxus, A insolitus, Spiroscala decorata, Euconospira equisita, Neilsonia invisitata, Worthenia parvula, Gosseletina nodosa, Glyptotomaria (Dictyotomaria) concinna, G. (D.) facta, G. (D.) decora, Phymatopleura preclara, Callispira grossa, Ceraunocochlis? subulata, Streptacis? ingens, and S.? complanata.

Correlation of marine stratigraphic units within the collection area are discussed. Zonation on the basis of pseudozygopleurid taxa, following that of Anderson et al. (1989), is presented as well as mention of characteristic taxa of the various series.

Liromissus, a new genus of chionine bivalve from the Neogene of Venezuela, serves as an example of the link between geographic range, endemism and extinction susceptibility. Unlike other Neogene tropical American chionine genera, Liromissus was not widespread in the tropical Western Atlantic and Eastern Pacific, but was instead restricted to the Atlantic Gatunian region. Late Neogene extinctions in tropical America affected taxa with restricted geographic ranges, and regions with higher degrees of endemism more severely. Accordingly, Liromissus is the only tropical chionine genus to suffer extinction during the Neogene.

The type species of Liromissus, L. quirosensis, was originally described as a member of the genus Lirophora. Morphological considerations preclude this assignment, but also demonstrate that Liromissus possesses all the characters diagnostic of the Chioninae.

The bivalve molluscs Colpomya? sp. and Goniophorina (Cosmogoniophorina)? tenuicostata Harrington are recorded for the first time in the Arenigian Suri Formation (Famatina Range, western Argentina), and the new taxa Suria ovalis new genus and new species, and Redonia riojana new species are proposed. Additionally, the rostroconchid Ribeiria spinosa Babin and Branisa is also described. Some taxa shared with the Acoite Formation (Cordillera Oriental, Northwestern Argentina) and the Sella Formation (Cordillera Oriental, Bolivia) suggest that the Suri Formation was geographically related to these basins, and consequently, it could likewise be considered as a peri-Gondwanan area.

Living ectocochliate cephalopods have long been thought to be restricted to a single genus, Nautilus Linnaeus, 1758, comprising five or six extant species. The shells of two species, N. scrobiculatus Lightfoot, 1786, and N. perforatus Conrad, 1847, are quite distinct, but no soft-parts were known until 1984, when N. scrobiculatus was seen alive for the first time. Dissections show that significant anatomical differences exist between N. scrobiculatus and other Nautilus species, including differences in gill morphology and details of the male reproductive system. These differences, along with phylogenetic analysis of extant and selected fossil nautiloid species, indicate that N. scrobiculatus, and N. perforatus should be distinguished from Nautilus as a newly defined genus, Allonautilus. This analysis contradicts previous phylogenies proposed for the Nautilida, which placed Nautilus as the last-evolved member of the order. We surmise that Allonautilus is a descendent of Nautilus, that the latter is paraphyletic, and first evolved in the Mesozoic, rather than in the late Cenozoic, as has been previously suggested.

Seven species of oryctocephalids occur in the Lower to Middle Cambrian boundary strata of the southern Great Basin. These include Oryctocephalites palmeri n. sp. and an Oryctocephalinae species from the uppermost Lower Cambrian (upper Olenellus Biozone); Oryctocephalus indicus (Reed, 1910), Microryctocara nevadensis n. gen. and n. sp., and Oryctocephalites rasettii n. sp. near the base of the Middle Cambrian (lower Plagiura Biozone); and Oryctocephalus primus Walcott, 1886, and Oryctocephalus nyensis Palmer, 1979, from slightly higher strata (upper Plagiura Biozone). Oryctocephalus and Oryctocephalites are emended based on a cladistic analysis of Oryctocephalinae Beecher, 1897.

Although echinoderm debris is locally common, articulated specimens are rare in Late Cambrian rocks from the Great Basin and Rocky Mountains of the western United States and are mostly associated with hardgrounds. The fauna, including cornute stylophorans, trachelocrinid eocrinoids, solute homoiosteleans, and rare edrioasteroids, includes several members of the archaic Cambrian Evolutionary Fauna, which had already passed its maximum diversity for echinoderms. In addition to the low diversity, articulated specimen abundance is very low, averaging only about one-tenth that found in overlying Lower Ordovician units. The transition between the Cambrian and Paleozoic Evolutionary Faunas for echinoderms in North America apparently occurred rapidly very close to the Cambrian-Ordovician boundary, because no unequivocal examples of the Paleozoic fauna (such as crinoids, glyptocystitid rhombiferans, asteroids, or echinoids) were found in the Late Cambrian sections.

New taxa include several cothurnocystid stylophorans assigned to Acuticarpus delticus, new genus and species, Acuticarpus? republicensis, new species, and Archaeocothurnus goshutensis, new genus and species; Scotiaecystis? species, a poorly preserved cornute stylophoran with lamellipores; Minervaecystis? species, a fragmentary solute homoiostelean based on several steles; Tatonkacystis codyensis, new genus and species, a well-preserved trachelocrinid eocrinoid with five unbranched arms bearing numerous brachioles; an unnamed, poorly preserved, epispire-bearing eocrinoid; an unnamed, poorly preserved, globular eocrinoid? lacking epispires; and an unnamed, heavily weathered, edrioasterid edrioasteroid. Nearly all holdfasts found in these Upper Cambrian units are single-piece blastozoan types, probably belonging to trachelocrinid and other eocrinoids. Distinctive columnals and thecal plates of several additional undescribed eocrinoids and other echinoderms were locally abundant and are also described.

Review of recently collected material of Eohiodon from North America suggests that there are two valid species, E. rosei (Hussakof) and E. woodroffi Wilson. Eohiodon falcatus Grande is identical to E. woodruffi in known skeletal features and nearly all meristic features and is treated as a junior synonym of the latter. The fossil genus Eohiodon Cavender differs from Hiodon Lesueur, which is known from both fossil and extant species, in numerous meristic and osteological features. The caudal skeleton in Eohiodon is nearly identical to that in Hiodon.

The traditionally accepted Notopteroidei, containing Lycopteridae, Hiodontidae, and Notopteridae, is a polypheletic group. The Asian fossil family Lycopteridae is not more closely related to Hiodontidae than it is to other taxa in the Osteoglossomorpha, but is sister to all other Osteoglossomorpha. The Hiodontiformes sensu stricto, including only the family Hiodontidae, is the sister-group of the Osteoglossiformes. This family is not more closely related to notopterids than to other taxa in Osteoglossiformes. The Notopteridae are most closely related to the Mormyroidea; together they and the fossil family Ostariostomidae constitute the sister-group of the Osteoglossoidei.

Fossil records of Hiodontiformes sensu stricto and Notopteroidei indicate a widespread pre-Neogene biogeographic range of these freshwater teleosts, suggesting that extinction must have been involved in the Cenozoic evolution of these two osteoglossomorph sublineages.

Several dinosaurs, notably Ouranosaurus and Spinosaurus, have vertebral columns marked by prominent arrays of elongated neural spines. Using pelycosaurian sailbacks like Dimetrodon as analogies, popular orthodoxy holds that the tall spines served as supporting struts for dorsal sails of purported thermoregulatory function, especially heat dissipation in tropical climates. It is argued here that the neural spines of Ouranosaurus, Spinosaurus, and several other long-spined dinosaurs favor bison-like humps rather than sails: 1) in functional morphology and relative elongation they are dissimilar to pelycosaur spines but homoplastically converge on the spines of high-withered ungulates; 2) the usefulness of a sail in thermoregulation has been exaggerated—in large tetrapods it would have been fairly efficient as a thermal amplifier but ineffective as a radiator; hence large sail-bearing dinosaurs in open tropical climates are improbable; 3) the insulation properties of humps favor gigantothermy, the most likely thermobiological model for large dinosaurs.

Dinosaur humps are probable adaptations for: 1) energy storage, maintenance of gigantothermy, and heat-shielding in unshaded habitats; 2) long-distance migration from feeding to nesting grounds across terrains of variable productivity; and 3) lipid conservation for production of large clutches of eggs at the nesting site. Because sacral, caudal, or dorsal humps were relatively common traits among certain groups, the fashionably anorexic image of many large dinosaurs must be emended.

The archosaur fauna from the Woodbine Formation (Cenomanian), Tarrant County, Texas includes crocodiles, theropod, nodosaurid, and hadrosaurid dinosaurs. A new neosuchian crocodile, Woodbinesuchus byersmauricei new genus and species, appears to be a longirostrine goniopholid. Isolated theropod teeth include morphotypes similar to Richardoestesia. Nodosaurid premaxillary teeth are unique among early nodosaurids in having no marginal cusps. Hadrosaurid remains represent the oldest hadrosaurs east of the Western Interior Seaway.

Late Cretaceous dinosaur eggshell assemblages from six localities of the Tremp basin (Southern Pyrenees, Lleida, Spain) are studied and compared with those of Southern France, to correlate their temporal succession. Fontllonga 6 reveals the most diverse eggshell assemblage known so far, with seven oospecies, among which one new structural type (Pseudogeckoolithus nodosus new genus and species), a new Ratite-type eggshell (Ageroolithus fontllongensis new genus and species) and a new Prismatoolithidae are described; four other taxa are shared with Southern France. The correlation of both Spanish and French eggshell successions allows us to recognize three main periods characterised by different eggshell assemblages: a lower assemblage with Megaloolithus petralta, M. aureliensis, Prismatoolithus tenuis and P. matellensis from the French Lower Rognacian and the Spanish sites Fontllonga 6 and Moro; a middle one with M. siruguei from the Middle Rognacian and Biscarri; and a late one from the Late Rognacian with M. mammilare (from Abella and Bastus) and M. pseudomamillare (from Suterranya). Some contradictions appear when comparing results with paleomagnetism and charophyte correlations but the eggshell correlations are consistent with other stratigraphic studies.

A phylogenetic analysis was conducted to address evolutionary relationships among the earliest members of the Miacidae (one of two early Cenozoic carnivoran families) and to ascertain the position of an ambiguous taxon, “Miacis” jepseni, with respect to the genera Miacis, Uintacyon, Vulpavus, Vassacyon, and Oödectes. The results of this analysis indicate that “Miacis” jepseni should be referred to the genus Oödectes, and both genus and currently included species are rediagnosed. The phylogenetic relationship of Oödectes to other miacids, and relationships among early Eocene miacids more generally, however, are less well resolved. Support is found for sister taxon relationships between Miacis and Vulpavus and between Uintacyon and Vassacyon, and it is suggested that this latter clade is the sister taxon to all other members of Miacidae.