Highlights d Dinosaurs and early birds had similar relative brain sizes d Major shifts in brain-body integration occur in the aftermath of the K-Pg extinction d Rates of brain-body evolution are highest in non-avian dinosaurs, early-diverging birds, parrots, and crows d Corvids, like hominins, evolved larger relative brains and bodies simultaneously

Archosaurs and mammals exhibit skeletal pneumaticity, where bone is infilled by airfilled soft tissues. Some theropod dinosaurs possess extensively pneumatic skulls in which many of the individual bones are hollowed out by diverticula of three main cranial sinus systems: the paranasal, suborbital, and tympanic sinuses. Computed tomography (CT scanning) permits detailed study of the internal morphology of cranial sinuses. But only a few theropod specimens have yet been subjected to this type of analysis. We present CT scans of the remarkably preserved and disarticulated skull bones of the long-snouted tyrannosaurid theropod Alioramus. These scans indicate that Alioramus has extensive cranial pneumaticity, with pneumatic sinuses invading the maxilla, lacrimal, jugal, squamosal, quadrate, palatine, ectopterygoid, and surangular. Pneumaticity is not present, however, in the nasal, postorbital, quadratojugal, pterygoid, or angular. Comparisons between Alioramus and other theropods (most importantly the closely related Tyrannosaurus) show that the cranial sinuses of Alioramus are modified to fill the long-snouted skull of this taxon, and that Alioramus has an extreme degree of cranial pneumaticity compared to other theropods, which may be the result of the juvenile status of the specimen, a difference in feeding style between Alioramus and other theropods, or passive processes. Based on these comparisons, we provide a revised terminology of cranial pneumatic structures and review the distribution, variation, and evo-

The phylogenetic position of the Indian gharial (Gavialis gangeticus) is disputed - morphological characters place Gavialis as the sister to all other extant crocodylians, whereas molecular and combined analyses find Gavialis and the false gharial (Tomistoma schlegelii) to be sister taxa. Geometric morphometric techniques have only begun to be applied to this issue, but most of these studies have focused on the exterior of the skull. The braincase has provided useful phylogenetic information for basal crurotarsans, but has not been explored for the crown group. The Eustachian system is thought to vary phylogenetically in Crocodylia, but has not been analytically tested. To determine if gross morphology of the crocodylian braincase proves informative to the relationships of Gavialis and Tomistoma, we used two- and three-dimensional geometric morphometric approaches. Internal braincase images were obtained using high-resolution computerized tomography scans. A principal components analysis identified that the first component axis was primarily associated with size and did not show groupings that divide the specimens by phylogenetic affinity. Sliding semi-landmarks and a relative warp analysis indicate that a unique Eustachian morphology separates Gavialis from other extant members of Crocodylia. Ontogenetic expansion of the braincase results in a more dorsoventrally elongate median Eustachian canal. Changes in the shape of the Eustachian system do provide phylogenetic distinctions between major crocodylian clades. Each morphometric dataset, consisting of continuous morphological characters, was added independently to a combined cladistic analysis of discrete morphological and molecular characters. The braincase data alone produced a clade that included crocodylids and Gavialis, whereas the Eustachian data resulted in Gavialis being considered a basally divergent lineage. When each morphometric dataset was used in a combined analysis with discrete morphological and molecular characters, it generated a tree that matched the topology of the molecular phylogeny of Crocodylia.

Birds have evolved behavioral and morphological adaptations for powered flight. Many aspects of this transition are unknown, including the neuroanatomical changes that made flight possible [1]. To understand how the avian brain drives this complex behavior, we utilized positron emission tomography (PET) scanning and the tracer (18)F-fluorodeoxyglucose (FDG) to document regional metabolic activity in the brain associated with a variety of locomotor behaviors. FDG studies are typically employed in rats [2] though the technology has been applied to birds [3]. We examined whole-brain function in European Starlings (Sturnus vulgaris), trained to fly in a wind tunnel while metabolizing the tracer. Drawing on predictions from early anatomical studies [4], we hypothesized increased metabolic activity in the Wulst and functionally related visual brain regions during flight. We found that flight behaviors correlated positively with entopallia and Wulst activity, but negatively with thalamic activity.