The present study of the genus Doryaspis (Heterostraci, Pteraspidiformes), based on new material from the Wood Bay Formation (Lower Devonian) of Vestspitsbergen, includes a morphological description of a new species, Doryaspis arctica, sp. nov., the revision of the type species of the genus, Doryaspis nathorsti, and the description of its first complete caudal fin. From these new data, some morpho-functional considerations are outlined. A phylogenetic analysis, based on 30 morphological characters and performed to answer the question of the position of Doryaspis within the Pteraspidiformes, suggests that Doryaspis is most closely related to Drepanaspis.

In Brazil, albuloid fishes have only been found in the Cretaceous of Chapada do Araripe, Northeastern Brazil, particularly in the Romualdo Member, Santana Formation. In this paper we describe †Farinichthys gigas, gen. et sp. nov., a large albuloid fish from the Paleocene of the Maria Farinha Formation, Pernambuco–Paraíba Basin, based on a large skull, disarticulated suspensorium and isolated vertebrae. The fish is the most complete fossil vertebrate hitherto obtained from that formation and the oldest record of Albulidae in South America. It is preserved in a clay marl in association with bivalve and gastropod shells, brachyuran and echinoid carapaces, and insects, in addition to fish and reptile remains. Regarding other known albulids (e.g., Albula, †Deltaichthys and †Lebonichthys), the new genus differs mainly by the absence of contact between the epioccipital and the parietal bones, a very elongate ventral process of the quadrate, an oblique groove on the external surface of the hyomandibula, and a parietal branch of the supraorbital sensory canal directed towards the parietal without reaching it. The presence of an ossified interorbital septum, an elongate horizontal preopercular arm, and the ascending process of the subopercle reaching the articular facet for the hyomandibula define a clade formed by †Farinichthys gigas plus Albula. It suggests an extension of the minimal age of this clade to the Paleocene (Danian).

A new specimen of the ichthyosaur Qianichthyosaurus zhoui Li, 1999, from the Late Triassic of southeastern China shares many characters with the poorly known genus Toretocnemus californicus Merriam, 1903, from the Carnian of California. Both species have a femur with a greatly expanded distal end, three primary and one accessory digits in front and hind limbs, and notching on both leading and trailing edges of the flippers. Qianichthyosaurus is referred to the Family Toretocnemidae Maisch and Matzke, 2000. The close relationship between these two taxa suggests a trans-Pacific distribution of ichthyosaur faunas in the Triassic.

Using three-dimensional, digitized data of the crania and maxillary teeth of seventeen theropod dinosaurs, biomechanical analysis reveals a series of interrelated correlations between the sizes, orientations, and ellipticity (narrowness) of the orbits and the inferred mechanical properties of the skull and teeth that relate to biting. A value for the sagittal bending strength of a cranium was computed at the longitudinal position of the orbit under an assumed load applied at the longitudinal position of the longest maxillary tooth. With the area of the orbit expressed as a percentage of the total lateral area of the skull, an inverse relationship was found to exist between the area of the orbit and the bending strength of the skull. Orbits with long-axis inclination angles in the range of 150° ± 15° are associated with taxa possessing small teeth and relatively weak skulls. Orbits with inclinations in the range of 95° ± 10° are associated with taxa possessing relatively strong skulls and long and/or strong teeth. In weak-skulled taxa, the long axes of the orbits are orientated at angles of not less than 45° to the mean inclination direction of the maxillary teeth. In strong-skulled taxa, the long axes of the orbits are sub-parallel to mean maxillary tooth direction. Finally, the ellipticity of the orbits are positively correlated with the strengths of skulls. It is proposed that the form of the orbital opening in theropods with strong skulls is governed by the requirements of the posterior half of the skull to resist the muscle generated forces associated with prey capture and/or dismemberment.

Pachycephalosaurian specimens from the Upper Cretaceous (upper Campanian) Kirtland Formation of northwestern New Mexico include a partial skull that preserves much of the basicranium. It represents a new genus and species, Sphaerotholus goodwini. A new species, S. buchholtzae, from the upper Maastrichtian Hell Creek Formation of Montana is referred to this genus. Additional New Mexico pachycephalosaurians include a partial dentary with associated skull material that is tentatively referred to S. goodwini and a partial frontoparietal that is referred to Pachycephalosauridae incertae sedis.

On the basis of a hypothetical growth series of Stegoceras, we excluded characters based on dome development and suture closure from a cladistic analysis of pachycephalosaurian relationships. Ornatotholus browni, the only putative “flat-headed” pachycephalosaurian from North America, is considered a nomen dubium and may represent a juvenile Stegoceras. Gravitholus albertae is an adult Stegoceras sp.; Stegoceras edmontonense is a nomen dubium and is referred to cf. Sphaerotholus sp.

Based on the results of a quantitative cladistic analysis, Stegoceras (including Stegoceras breve, S. lambei, S. sternbergi, and UCMP 130051) is the sister taxon to all other domed pachycephalosaurians. Derived pachycephalosaurids consist of two principal clades: a lineage that includes Stygimoloch, Pachycephalosaurus, and Sphaerotholus and a lineage represented by the Asian taxa, Tylocephale and Prenocephale.

With biogeographic occurrences mapped onto the phylogeny, a single dispersal event from Asia into North America, followed by dispersal of Prenocephale and Tylocephale into Asia prior to the late Campanian is indicated (ACCTRAN) or two independent dispersals into North America prior to the late Campanian is indicated (DELTRAN). Pachycephalosaurian phylogeny does not support Asian-North American contiguity throughout the Campanian and Maastrichtian.

Giganotosaurus carolinii is one of the largest known theropod dinosaurs. Its remains include a well-preserved braincase that displays a suite of derived characters unique to the animal, and others that help establish its relationships amongst the Theropoda. These include the development of a broad frontoparietal skull table that forms a shelf overhanging the supratemporal fenestra, the reorientation of the metotic fissure and fenestra ovalis onto the occiput, the ventral extension of the supraoccipital on either side of the foramen magnum, a broad but low occipital condyle, and pneumatization of the basioccipital. Some characters suggest affinities with South American abelisaurids, but many support a sister grouping of Giganotosaurus and Carcharodontosaurus within a larger group that includes the Asian sinraptorids. The close affinities of Giganotosaurus with the northern African Carcharodontosaurus support the hypothesis of intercontinental connections until mid-Cretaceous times.

The skeletal material of Wonambi naracoortensis has been re-examined, and used to test its phylogenetic relationships. The skeletal description, and the resulting data matrix, concentrates on characters that can be assessed by observation (on the associated material of Wonambi kept at the South Australian Museum). Macrostomatan affinities of Wonambi prove to be well supported. The taxon nests within Macrostomata, above Xenopeltis and Loxocemus.

Highly detailed microscopic preparation of both newly discovered and previously undescribed nimravine crania from the White River Group of North America reveals hitherto unreported morphological features of the basicranium and auditory region, particularly the composition of the auditory bulla and form of the petrosal. The monophyly of Dinictis, Hoplophoneus, and Nimravus is supported by a remarkably uniform configuration of the auditory bulla: (1) the form and placement of the entotympanics; (2) a near-vertical ectotympanic with elaborate styliform process partially enclosing the Eustachian tube; and (3) an anterior bulla wall formed by a unique overlap of the anterior entotympanic lamina by the elongate styliform process. Although an intact auditory bulla is unknown in an Eurasian nimravine, the auditory regions of the species represented by crania (Eusmilus bidentatus and Nimravus cf. intermedius from Quercy) demonstrate a definite affinity with New World genera, affirming the Holarctic distribution of the Nimravinae. In addition to identifying basicranial similarities among nimravines, we describe the first largely intact turbinate bones within the nasal cavity of a nimravid. CT (computed tomography) scanning of nimravid rostra reveals differing configurations of the maxilloturbinate in Dinictis and Hoplophoneus, the former more derived than the latter. Compared to other Carnivora, nimravid maxilloturbinates are most similar to those of living aeluroids, which are confined to the ventral part of the anterior nasal cavity. Nimravids lack the elaborately branching (dendrolamellar) maxilloturbinates of arctoid and cynoid carnivorans.