Baugeichthys caeruelus gen. et sp. nov., a new albuliform from the Hauterivian of the Massif des Bauges (France), is described. This taxon is the oldest albuliform known to date. Most of the characters of Baugeichthys caeruleus are plesiomorphic and common to all the basal teleosts (e.g., very short supraoccipital crest, parietals meeting in the midline, caudal scutes, fringing fulcra, two ural centra, and three epurals). However, this fish exhibits elopomorph synapomorphies: a mass of cartilage above the first ural centrum and the presence of a pectoral splint. Albuliform synapomorphies are not visible because of poor preservation. Nevertheless, the entire morphology, especially the caudal skeleton, is quite similar to that of other albuliforms. This fish appears to be a basal albuliform, yet more primitive than albuloids, and is thus classified as a plesion incertae sedis within the Albuliformes.

Genypterus valdesensis, sp. nov. from the Puerto Madryn Formation in Península Valdés, Argentina is the first fossil ophidiid reported from South America and represents the first well preserved record of the genus worldwide. The specimen consists of a nearly complete articulated skull and some disarticulated postcranial elements. A thorough description is given of the osteological features of the species, which can be used to recognize it as a distinct taxon. The fossil species is characterized by the presence of a foramen on infraorbital 3 and by the square-shape of infraorbital 4. An array of morphological features taken in combination contribute to further differentiate G. valdesensis from the Recent species. This specimen also provides unequivocal evidence of the presence of the Ophidiiformes in the southwestern Atlantic Ocean 14 MA.

A large collection of fishes from Tanzania, East Africa, includes representatives of four or five families of fishes. The majority of specimens are cichlids, with at least five species being represented, distinguished by osteological characters such as the shape of the opercular bones, frontals, and supraoccipital crest. These species are all named and described in the same genus based on shared scale and squamation characters. The site, at Mahenge in the Singida Region, was a crater lake about half a kilometer in diameter. It has been dated as Eocene, about 46 Ma, based on radiometric techniques. The cichlid species, being very closely related, may have constituted a species flock, which would indicate that cichlids had the ability to form flocks as early as the Eocene.

A new species of dipnoan, Chirodipterus potteri, is described, based on a series of juvenile tooth plates with attached bone from two localities in New South Wales, Australia. Most of the material comes from the Upper Devonian (Fammenian) Coffee Hill Member of the Catombal Range, west of Orange, and some from the Upper Devonian (Frasnian) Paling Yard Formation, at Gap Creek. The new taxon provides additional insights into the fine structure and the development of chirodipterid tooth plates, and includes some anomalous specimens. Tooth plates are based on a form of interdenteonal dentine with irregular denteons containing circumpulpar dentine, surrounded by mantle dentine and enamel, and ankylosed to the underlying jaw bones. Analysis of the material indicates that the tooth plates of chirodipterid lungfish are not members of the dentine plated clade, but have tooth plates that are based, as in most other dipnoan species, on the fusion of radiating rows of initially separate cusps in the young juvenile to form a crushing or grinding structure in the adult.

Theropod teeth are taxonomically diagnostic components of dinosaur assemblages. Seventy teeth have been recovered from six different localities in the Kogosukruk Tongue of the Prince Creek Formation (Upper Cretaceous) of the North Slope of Alaska. This assemblage of teeth shows slightly less diversity compared to well documented assemblages of teeth from the slightly older Judith River Formation of south-central Montana, the Aguja Formation of west Texas, and the Hell Creek Formation of eastern Montana. In addition, in contrast to the Judith River Formation assemblage of teeth in south-central Montana, the teeth assigned to Troodon dominated the Alaskan assemblage. The dominance of Troodon is attributed to adaptation by this theropod to low light conditions while over-wintering at a high paleolatitude.

An articulated partial skeleton, including a nearly complete skull and left forelimb, of a crocodylomorph reptile from the Upper Triassic Chinle Formation of Ghost Ranch, New Mexico, is referable to Hesperosuchus agilis Colbert, 1952. It contributes much new information on the skeletal structure of this previously poorly known taxon. A large, circular palpebral bone is present in each orbit. The quadratojugal is particularly well preserved and suggests a reinterpretation of this element in related taxa including Sphenosuchus. Previous analyses of sphenosuchian relationships reached conflicting results, and a critical review of the characters used in these analyses is presented. A phylogenetic analysis of basal crocodylomorph taxa provides weak support for sphenosuchian monophyly, placing Hesperosuchus with Saltoposuchus, Dibothrosuchus, and Sphenosuchus.

Diademodon and Cynognathus were contemporary cynodonts that lived during the Early to Middle Triassic. Their fossilized remains are found in the same deposits and, in the absence of diagnostic cranial material, the postcranial skeletons of these animals are considered indistinguishable from one another. In this study the bone histology of Diademodon and Cynognathus was examined, using thin sections of several long bone elements. Distinctive histological patterns were recognized for each genus: the cortex of Diademodon is zonal, consisting of alternating bands of fibro-lamellar and lamellar bone tissue, whereas that of Cynognathus consists of uninterrupted fibro-lamellar bone tissue. The bone histology indicates that Diademodon had a cyclical growth strategy whereas Cynognathus grew continually, at a constant, rapid rate throughout the year. Quantification of the vascularization of the compacta using image analysis, has shown that the bone tissue of Cynognathus is significantly more vascularized than that of Diademodon. The marked differences in their bone histology and vascularization, have permitted the generic identification and distinction of postcranial material (limb bones) previously categorized as either Cynognathus or Diademodon. This study of Diademodon and Cynognathus is the first detailed examination of the bone histology of representatives of the Triassic Cynodontia. The characteristic patterns of bone histology in Diademodon and Cynognathus have directly revealed information about their growth strategies and has demonstrated the use of bone histology to distinguish between the genera when associated cranial material is absent.

Based on an extensive survey of quadrate morphology in extant and fossil birds, a complete quadrate from the Maastrichtian Lance Formation has been assigned to a new genus of most probably odontognathous birds. The quadrate shares with that of the Odontognathae a rare configuration of the mandibular condyles and primitive avian traits, and with the Hesperornithidae a unique pterygoid articulation and a poorly defined (if any) division of the head. However, the quadrate differs from that of the Hesperornithidae by a hinge-like temporal articulation, a small size of the orbital process, a well-marked attachment for the medial (deep) layers of the protractor pterygoidei et quadrati muscle, and several other details. These differences, as well as the relatively small size of about 1.5–2.0 kg, suggest a feeding specialization different from that of Hesperornithidae.

The marine squamate, Dolichosaurus longicollis, from the Upper Cretaceous (Cenomanian) Chalk deposits of southeast England is redescribed. The elongate neck of D. longicollis is produced by an increased number of cervical vertebrae. Cervical peduncles are elongate, curved and are not fused to the hypapophyses. There is no scapulocoracoid fenestra, the coracoid is not emarginated, and the scapula and coracoid are not fused. The splenial and angular articulate in a ball-and-socket joint similar to that of mosasaurs and Coniasaurus crassidens. The forelimb and pectoral girdle elements show evidence of reduction as compared to the pelvic girdle and rearlimb. Cladistic analysis of six mosasaur taxa, three ‘aigialosaur’ taxa, Coniasaurus crassidens, Coniasaurus gracilodens, and D. longicollis, using 66 characters, found 27 most parsimonious cladograms (MPCs): 122 steps; C.I. 0.648; H.I. 0.352; R.I. 0.669. A Strict Consensus Tree found support for the monophyly of the Mosasauridae and Aigialosauridae; sister-group relationships between coniasaurs, Dolichosaurus, Aigialosauridae and Mosasauridae are an unresolved polytomy. A Majority Rule Consensus Tree finds Dolichosaurus as sistergroup to (C. crassidens, C. gracilodens (Aigialosauridae (Mosasauridae))) in nine (33%) of the MPCs. Lack of support for a more inclusive Dolichosauridae composed of Dolichosaurus (C. crassidens, C. gracilodens) is attributed to the incompleteness of the fossil remains of these three taxa. Presence/absence of a pectoral girdle currently defines the presence/absence of a neck. This definition is insufficient and hypapophyses are found more informative regarding taxic differences and transformational scenarios. The paleobiology of Dolichosaurus is reconstructed as similar to coniasaurs, nothosaurs, and modern sea snakes.

A new bat, Karstala silva, gen. et sp. nov., is described from the early Miocene (early Hemingfordian) Thomas Farm local fauna, Gilchrist County, Florida. The new taxon is represented by an upper canine, posterior part of the dentary, isolated upper and lower molars, much of the humerus, and part of the radius. The myotodont configuration and steeply inclined lingual cingulid of m1-m2 separate Karstala from the Molossidae and most Vespertilionidae except Antrozous. Karstala differs from Antrozous in other molar details and from all molossids and North American vespertilionids in having a humerus with the combination of a rounded head, deep supraglenoid pit, long and high pectoral ridge, tiny olecranon fossa, and no notch between the medial side of the trochlea and spinous process. The new species is comparable in size to the larger known species of the Vespertilionidae and is the largest known bat in the Tertiary of North America.

The masticatory apparatus of Pampatherium typum, P. humboldtii, and Holmesina paulacoutoi are analysed based on skull, mandibular and dental morphology and the inferred masticatory musculature. Comparison of the apparatus with those of other pampatheres suggests a trend toward increasing ability to process resistant vegetation from Holmesina through Pampatherium. The mechanical design of the apparatus among these pampatheres is nearly identical and has apparently undergone only minor variation since pampatheres first appear in the fossil record, suggesting strong phylogenetic constraint in the form of skeletal and dental elements. Main differences among taxa occur in features associated with the musculature, and thus the primary means for differentiation in masticatory function, which is correlated with diet, were changes resulting in differential force imput. Although the taxonomic status of some specimens is equivocal, indications are that the Plio-Pleistocene paleobiogeographic distribution of pampatheres is correlated with masticatory function (and hence diet), with P. typum, the species best adapted for grinding coarse vegetation, occurring in the more arid Pampean regions of South America. H. occidentalis, although a capable grinder, was the least suited to coarse vegetation. It is known from deposits near the current Peru-Ecuador border, an area of humid lowlands during glacial maxima. H. paulacoutoi and P. humboldtii lie between these extremes, with the latter better adapted for abrasive vegetation. These pampatheres have been found at the same localities, mainly through Brazil, which was characterized by wetter conditions than the Pampas. Their presence together suggests either sympatry or occupation of the same region during different times, with their ranges moving either north (P. humboldtii) or south (H. paulacoutoi) in a transition zone that may have shifted in response to changes in glacial maxima and minima.

A fragmentary maxillar of a small anthracotheriid has been discovered in the middle Eocene locality of Kyawdaw in the Pondaung Formation (Myanmar). This specimen represents a primitive new species (Siamotherium pondaungensis, sp. nov.), possibly ancestral to Siamotherium krabiense from the late Eocene of Krabi (Thailand). The occurrence of S. pondaungensis in Myanmar suggests that Krabi is younger than the localities of the Pondaung Formation, and it further supports the role that southern Asia played in the origin and evolution of several groups of mammals.

A categorical distinction is made between two types of biostratigraphic units. In a given superposed section, a eubiostratigraphic unit is a thickness of strata whose boundaries are defined by the lowest and/or highest occurrences of fossils of one or more specified taxa. In contrast, a quasibiostratigraphic unit is a thickness of strata characterized by its fossil content, but whose boundaries are defined by other means.

Eubiostratigraphic units include range, single-taxon interval, assemblage, and multiple-taxon interval fossilzones. Quasibiostratigraphic units include paleontologically distinct lithozones, metrizones, and “fuzzy” zones. Quasibiostratigraphic units serve to summarize the most distinctive changes in overall fossil content observed in individual sections, without necessary regard for the exact vertical ranges of particular taxa. Most quasibiostratigraphic units need not be given formal binomial names, but are best assigned alpha-numeric or informal descriptive designations.

Assemblage fossilzones are multiple-taxon analogs of range fossilzones, in that they are defined by a single set of two or more taxa. Multiple-taxon interval fossilzones are multiple-taxon analogs of single-taxon interval fossilzones, in that their boundaries are defined by two different sets of two or more taxa. As such, multiple-taxon interval fossilzones are stratigraphically and temporally contiguous with one another by definition.