Vertebrate tracks are comparatively rare in Tertiary deposits of the western United States. Unlike the deposits of the Mesozoic in this region, in which each formation often has several dozen known tracksites, there are only a few known sites in Paleocene units of the region (Lockley and Hunt, 1995), and though the Eocene Green River Formation contains relatively numerous tracks, especially those of birds, there are only a few taxa represented. The occurrence of amphibian tracks in the Eocene Wasatch Formation is therefore of interest, not only in that it adds to the known ichnological record of the Tertiary of the western United States but also in that the tracks indicate the presence of an otherwise under-represented member of the vertebrate paleofauna of the time. Skeletal remains of amphibians are present but not common in many Tertiary formations of the western United States, and remains of large salamanders are rare. Only the large caudate Piceoerpeton is known from the Tiffanian and Clarkforkian of Montana and Wyoming (Naylor and Krause, 1981), and its only Wasatchian occurrence is at Ellesmere Island, north of the Arctic Circle. The tracks described here appear to represent a nearly Piceoerpeton-sized salamander in the lacustrine shoreline deposits of the early Eocene Wasatch Formation of southwestern Wyoming.

The earliest known members of the Thais clade of rapanine muricid neogastropods comprise four species from the Cantaure Formation (early Miocene: Burdigalian) of Venezuela; three of these species are new. Neorapana rotundata Gibson-Smith et al., 1997, is most closely related to the Recent Pacific Mexican N. tuberculata (Sowerby, 1835), and represents the only known Atlantic occurrence of the genus. Thais brevicula new species is closest to T. callaoensis (Gray, 1828) from the Recent of northern Peru and the Galápagos. A review of the genus Thais indicates that the typical members of this group occur in the South Atlantic, West Africa, and eastern Pacific, but not in the Recent fauna of the southern Caribbean. Stramonita bifida new species is a large species related to the Recent S. haemastoma floridana (Conrad, 1837), which occurs throughout the Caribbean. A review of American species of Stramonita indicates that the taxon S. biserialis (de Blainville, 1832) from the Recent fauna of the eastern Pacific, and the taxon S. h. haemastoma (Linnaeus, 1767), may each be composed of more than one species despite the teleplanic dispersal of their larvae. Stramonita semiplicata new species is closely related to the Recent S. bicarinata (de Blainville, 1832) from the South Atlantic, and represents a lineage that occurred in the Caribbean region until at least the late Miocene. It may have given rise to the eastern Pacific genus Acanthais. The higher diversity and greater antipredatory specialization of eastern Pacific as compared to western Atlantic members of the Thais clade may have resulted from higher post-Miocene rates of speciation and lower extinction rates in the eastern Pacific.

Two new species of primitive cladid crinoids, Costalocrinus ibericus and C. thymos, from the Lower Devonian (Emsian) of northwest Spain, provide important information on the evolution of the Costalocrinus-Barycrinus lineage during the Devonian and Mississippian. Costalocrinus ibericus n. sp. is morphologically similar to Barycrinus rhombiferus (Owen and Shumard, 1852) from the Mississippian, except for the characters of the anal X plate and degree of calcification of the anal sac. These two species are separated by approximately 55 m.y. and provide evidence of slow morphologic change, or phenotypic bradytely, in this lineage. Such slow morphologic change is consistent with the previous interpretation of Barycrinus as an ecologic generalist. Very few other genera of Paleozoic crinoids evolved at such a slow rate. Costalocrinus thymos n. sp. is more typical of other species of Costalocrinus from the Middle Devonian and Lower Mississippian. Phylogenetic analysis suggests the ancestral lineage of the Mississippian genus Barycrinus evolved from Costalocrinus near the base of its radiation in the Early Devonian (Emsian).

The origin of tetrapods from sarcopterygian fish in the Late Devonian is one of the best known major transitions in the history of vertebrates. Unfortunately, extensive gaps in the fossil record of the Lower Carboniferous and Triassic make it very difficult to establish the nature of relationships among Paleozoic tetrapods, or their specific affinities with modern amphibians. The major lineages of Paleozoic labyrinthodonts and lepospondyls are not adequately known until after a 20–30 m.y. gap in the Early Carboniferous fossil record, by which time they were highly divergent in anatomy, ways of life, and patterns of development. An even wider temporal and morphological gap separates modern amphibians from any plausible Permo-Carboniferous ancestors. The oldest known caecilian shows numerous synapomorphies with the lepospondyl microsaur Rhynchonkos. Adult anatomy and patterns of development in frogs and salamanders support their origin from different families of dissorophoid labyrinthodonts. The ancestry of amniotes apparently lies among very early anthracosaurs.

Field work conducted in the northeastern Aral Sea Region, southwestern Kazakhstan has produced a large number of vertebrates from late Cretaceous and early Tertiary sediments. Included among these vertebrates are sharks, bony fishes, amphibians, turtles, lizards, crocodiles, and dinosaurs. This fauna comes from three formations, the Turonian-Coniacian Zhirkindek, the Santonian-Campanian Bostobe, and the early Tertiary Akzhar formations. In this paper we describe the microvertebrate fauna. The Akzhar fauna consists only of marine sharks, one hexanchiform species (Notidanodon cf. loozi) and four lamniform species (Carcharias teretidens, Striatolamia striata, Otodus obliquus var. minor, and Palaeocarcharodon orientalis). These suggest a Paleocene age, most likely Selandian or earliest Thanetian. In addition to previously described components, the Bostobe fauna now includes a discoglossid frog and the lizard Slavoia cf. darevskii. This is the first Mesozoic record of each in Kazakhstan and the latest record anywhere of the latter. The Zhirkindek fauna is now known to include a varanid lizard.

One of the southernmost North American late Campanian microvertebrate assemblages was collected from the upper Aguja Formation, Big Bend National Park, Texas. The dinosaurs provide additional evidence that distinct southern and northern terrestrial vertebrate provinces occurred contemporaneously during this time due to latitudinal differences in temperature and rainfall. Southern areas, such as west Texas, were warm dry, with non-seasonal climates, and with open-canopy woodlands; they appear to be less fossil-rich and less diverse than northern areas. Nine dinosaurs are present, based on isolated teeth: pachycephalosaurid; hadrosaurid; ceratopsian; tyrannosaurid; Saurornitholestes cf. langstoni (Sues, 1978); Richardoestesia cf. gilmorei (Currie et al., 1990); a new species of Richardoestesia, which is named here; and a undetermined theropod unlike any previously described. Previous reports of Troodon sp. from the Talley Mt. and Terlingua microsites are mistaken; they are a pachycephalosaurid. Many of the dinosaur teeth are small, and are probably from juveniles or younger individuals, evidence that dinosaurs nested in the area. Paleoecologically, the upper Aguja was probably more similar to the lower and more inland faunas of the Scollard Formation (~66 Ma) of Alberta than to contemporaneous northern faunas: both had drier, open environments and lower dinosaur abundance. This connection between climate and dinosaur abundance suggests that climatic factors were important in the Late Cretaceous dinosaur extinctions.

Tonnoidean gastropods have planktotrophic larval lives of up to a year and are widely dispersed in ocean currents; the larvae maintain genetic exchange between adult populations. They therefore are expected to respond rapidly to new geographic barriers by either extinction or speciation. Fossil tonnoideans on the opposite coast of the Americas from their present-day range demonstrate that larval transport still was possible through Central America at the time of deposition of the fossils. Early Miocene occurrences of Cypraecassis tenuis (now eastern Pacific) in the Caribbean probably indicate that constriction of the Central American seaway had commenced by Middle Miocene time. Pliocene larval transport through the seaway is demonstrated by Bursa rugosa (now eastern Pacific) in Caribbean Miocene-latest Pliocene/Early Pleistocene rocks; Crossata ventricosa (eastern Pacific) in late Pliocene rocks of Atlantic Panama; Distorsio clathrata (western Atlantic) in middle Pliocene rocks of Ecuador; Cymatium wiegmanni (eastern Pacific) in middle Pliocene rocks of Atlantic Costa Rica; Sconsia sublaevigata (western Atlantic) in Pliocene rocks of Darien, Pacific Panama; and Distorsio constricta (eastern Pacific) in latest Pliocene-Early Pleistocene rocks of Atlantic Costa Rica. Continued Early or middle Pleistocene connections are demonstrated by Cymatium cingulatum (now Atlantic) in the Armuelles Formation of Pacific Panama. Tonnoideans indicate that the Central American seaway began to be constricted after early Miocene time, and some larval transport through the seaway was possible throughout Pliocene time. Intermittent marine connections were maintained at least during late Pliocene to early Pleistocene interglacial periods of high sea-level, and alternated with a land bridge during glacial periods of low sea-level.

A partial skeleton of Daspletosaurus sp. from the Late Cretaceous (Campanian) Two Medicine Formation of western Montana preserves the first gut contents reported for a tyrannosaurid. Associated remains found with this skeleton consist of acidetched vertebrae and a fragmentary dentary from juvenile hadrosaur dinosaurs. Hadrosaur bonebed data and comparisons of hadrosaur and tyrannosaurid limb proportions suggest that juvenile hadrosaurs represented both an abundant and accessible food source. The surface corrosion exhibited by the hadrosaur elements matches that produced by stomach acids and digestive enzymes in a wide variety of living vertebrates. Based upon these and other gut contents, and also upon tooth-marked bone studies, it appears that Daspletosaurus and most theropods ingested and digested prey in a manner similar to that of extant archosaurs (crocodilians and birds), employing a two-part stomach with an enzyme-producing proventriculus followed by a thick-walled muscular gizzard. This two-part stomach appears to be an archosaur synapomorphy.

Abundant examples of exoskeletal abnormalities have been known in various trilobites since Portlock's (1843) first report on a teratological pygidium of Phillipsia ornata (cf. Babcock, 2000). Owen (1985) and Babcock (1993) recognized three types of trilobite malformations: healed injuries, teratological conditions, and pathological conditions. It is not always easy, however, to distinguish between the various types of malformations, especially in case of teratological or pathological conditions. In general, healed injuries are considered to have resulted from trauma during molting (Walcott, 1883; Whittington, 1956; Henningsmoen, 1975; Snajdr, 1981; Owen, 1983; Ramsköld, 1984) or wounds by predatory attack (Ludvigsen, 1977; Rudkin, 1979; Ŝnajdr, 1979, 1981; Owen, 1985; Conway Morris and Jenkins, 1985; Babcock, 1993; Pratt, 1998). Many healed injuries are indicated by broken spine stumps, indented and cicatrized edges of exoskeletons, and callused or regenerated exoskeleton around the broken surface (Ŝnajdr, 1981; Owen, 1983; Babcock, 1993). Teratological conditions are represented primarily by the irregular development of glabellar lobes, cephalic borders, and pygidial border spines, and anomalous number of segments on the thorax and pygidium. For example, Owen (1980) described a teratological cranidium of Calyptaulax norvegicus with two additional lateral glabellar lobes between the l p and 2p lobes. On the other hand, pathological conditions are marked by gall-like swellings and vermiform borings on exoskeletons that are thought to have been caused by diseases or parasitic infestation (Lochman, 1941; Ŝnajdr, 1978; Conway Morris, 1981; Owen, 1985).

Fossil crinoids are described from the Lesser Antilles for the first time. Crinoids are now known to occur in the Miocene of Carriacou, the Grenadines (four species), and in the Eocene and Miocene of Barbados (three species). Taxa include: isocrinid sp. indet., hyocrinid sp. indet. (both Eocene); the isocrinids Neocrinus decorus (Wyville Thomson, 1864) and Isocrinus sp., the bourgueticrinid Democrinus? sp., and the comatulid Horaeometra sp. (all Miocene). Despite the preponderance of taxa in open nomenclature, these are among the very few records of fossil crinoids from the Antillean region. Faunas are dominated by the columnals of isocrinids; bourgueticrinid and millericrinid columnals, and comatulid centrodorsals, are very rare, despite comatulids being both the most diverse crinoids in the modern fauna and the only group that occurs in shallow-water environments. Post-Eocene crinoid faunas in the Antillean region include taxa that are similar, at least at the generic level, to those of the present day. Democrinus? sp. from Carriacou is the first pre-Quaternary bourgueticrinid from the Antilles. Horaeometra sp. is the first fossil comatulid from the Antilles to be classified to generic level.

The extant crinoid fauna of the tropical western Atlantic includes 23 genera/34 species of “stalkless” comatulid crinoids and eight genera/ten species of stalked crinoids. This is far greater than the known diversity of fossil crinoids from the Antillean region, which spans circa 120 Ma. The apparent rarity of fossil crinoids is probably part artefact, produced by collection bias, taphonomic effects, and the relative rarity of exposures of sedimentary units deposited in 150+ m, i.e., the environment of extant stalked crinoids.

The seventy-fifth anniversary of the Journal of Paleontology presents a felicitous opportunity to review major changes in interpretation of mammalian phylogeny. Founding of the journal coincides with the nascence of the career of the most influential paleomammalogist of the past century, George Gaylord Simpson (1902-1984). It occurred at a time when now-archaic models for mammalian systematics and evolution, such as the aristogenesis of H. F. Osborn (1857-1935) and the typological concept of taxa, were prevalent (e.g., Simpson, 1945). These models were soon to give way to “new ways of going at things” (Laporte, 2000, p. 87); most significantly, the incorporation of quantitative methods and the evolutionary synthesis (Simpson, 1944). Subsequent decades witnessed the rise and/or sophistication of other applications and perspectives in fossil-based interpretation of mammalian systematics, including form-function analysis (e.g., Szalay, 1994) and, particularly, cladistic approaches (e.g., McKenna, 1975). Within these broad ideological frameworks, major paradigm shifts have resulted from new discoveries, conceptual changes, or (most commonly) a combination of both. Finally, mammalian systematics currently lie at the verge of a monumental paradigm shift, providing important direction for the future.

We report the discovery of an extremely rich, previously undescribed Caribbean late Miocene to early Pliocene ichthyofauna represented by one hundred forty species of elasmobranchs and teleosteans from the Cubagua Formation, northeastern Venezuela. The fauna exhibits significant ecological differences compared with common neritic Caribbean Neogene assemblages. The bathymetric distributions of taxa, based on living counterparts, ranges from 0 to 100 m depth. The exceptional co-occurrence of deep water (epipelagic, mesopelagic and benthopelagic), and shallow water (neritic) taxa is best interpreted as the consequence of ocean upwelling in the proximity to the deep-water Cariaco Trench. Patterns of predator and prey are established and corroborate upwelling. Special remarks are made regarding previously unknown late Miocene to early Pliocene Caribbean ichthyofaunas, the absence or rarity of reported fossil taxa in the Recent Caribbean fauna, and a paleo- upwelling indicator (Lampadena jacksoni new species).