CLAESSENS, L.P.A.M.; Harvard University: Analysis of the Kinematics of Lung Ventilation in Crocodylians The skeletal and soft tissue kinematics of breathing in Alligator mississippiensis were examined by cineradiography as part of a project investigating the evolution of respiratory mechanisms in the Archosauria. Lung ventilation in A. mississippiensis is diphasic and arrhythmic, and consists of apneic […]

CARR, T. D.; University of Toronto: The limits of inferring sequence heterochrony in fossil species: integration of ontogeny and phylogeny in tyrannosaurs In neontology, sequence heterochrony advanced the study of intrinsic evolutionary processes by recognizing that the order of growth events is unique to each species. The methods of sequence heterochrony can be applied to […]

GEIST, N.R.; JONES, T.D.; HILLENIUS, W.J.; RUBEN, J.A.; Sonoma State Univ.; Stephen F. Austin State Univ.; College of Charleston; Oregon State Univ.: New Evidence for Diaphragm Breathing in Pterosaurs With few exceptions, amniotes ventilate their lungs by ribcage expansion. Mammals and crocodilians supplement costally powered lung ventilation with active diaphragms, and birds couple thoracic expansion […]

WITMER, L. M.*; CHATTERJEE, S.; FRANZOSA, J.; ROWE, T.; RIDGELY, R.; Ohio Univ., Athens; Texas Tech Univ., Lubbock; Univ. of Texas, Austin; Univ. of Texas, Austin; Ohio Univ., Athens: Neuroanatomy and vestibular apparatus of pterosaurs: Implications for flight, posture, and behavior Comparison of birds and pterosaurs, the two archosaurian flyers, sheds light on adaptation to […]

JONES, T. D.; RUBEN, J. A.; HAVNER, R. W.; FRIEDFELD, R. B.; GEIST, N. R.; Stephen F. Austin State University; Oregon State University; Stephen F. Austin State University; Stephen F. Austin State University; Sonoma State University: INVESTIGATION OF SUPPOSED FEATHERS OF DINOSAURS FROM CHINA Feather fossilization generally involves autolithification of bacteria associated with feather decomposition. […]

RYBCZYNSKI, Natalia; Canadian Museum of Nature, Ottawa: Behavioral evolution in fossil castorids (beavers) Castorids present an unusual opportunity to study behavioral evolution because their robust fossil record includes numerous behavioral artifacts. For some castorids the behavioral evidence indicates a close correspondence between behavioral and morphological specialization, but in other cases the behavioral trait appear unassociated […]

CONRAD, J.L.*; SERENO, P.C.; Univ. of Chicago; Univ. of Chicago: An Early Cretaceous lizard skull from Mongolia and the early evolution of Gekkota Fossil evidence of Gekkota, and particularly its stem taxa, remains scanty. The earliest records are nearly as derived as extant members and, consequently, phylogenetic uncertainty persists regarding the relationships of Gekkota. Suggested […]

WILSON, P.*; CASTELLANOS, M.C.; THOMSON, J.D.; California State Univ. Northridge: Pollen Presentation by Bee- and Bird-Adapted Flowers Penstemon flowers are pleiomorphically bee-pollinated, but there has been repeated convergence toward hummingbird pollination. Hummingbirds do not groom as much as bees and have flatter pollen carryover curves. This led us to hypothesize that bird-pollinated species ought to […]

MACDOUGALL-SHACKLETON, E.A.; DERRYBERRY, E.P.; FOUFOPOULOS, J.; DOBSON, A.P.; HAHN, T.P.; University of Western Ontario; Duke University; University of Michigan; Princeton University; University of California, Davis: Parasite-mediated heterozygote advantage in an outbred songbird population Coevolution with parasites is thought to maintain genetic diversity in host populations. However, while there are sound theoretical reasons to expect heterozygosity […]

ROWE, A.H.*; ROWE, M.P.; North Carolina State Univ.; Appalachian State Univ.: Coevolution between grasshopper mice (Onychomys spp.) and bark and striped scorpions (Centruroides spp.) Asymmetrical selection has been proposed as the strongest argument for rejecting hypotheses of coevolutionary arms races between predators and prey. While predators exert strong selection against prey, prey exert only weak […]