PASSAMANECK, Y.J.*; HALANYCH, K.M.: Lophotrochozoan relationships inferred from 28S rDNA sequences 28S rDNA has been sequenced from a variety of taxa to investigate evolutionary relationships within the Lophotrochozoa. The clade Lophotrochozoa, which includes annelids, mollusks, and the three lophophorate taxa (bryozoans, brachiopods, and phoronids), was first identified based based upon analysis of 18S rDNA. Analyses […]

BEGOVIC, E.: Feeding Specialization and Diversification Patterns of Eastern Pacific Patellogastropoda To investigate the role that feeding specialization may play in clade diversification and mode of speciation, I have begun preliminary phylogenetic and sterol analyses of eastern Pacific Patellogastropoda. A phylogenetic hypothesis for eastern Pacific Patellogastropoda is constructed using mtDNA sequences from the large ribosomal […]

GEIST, N. R.*; JONES, T. D.; RUBEN, J. A. ; HILLENIUS, W. J.; FREY, E. D.: Lung Ventilation Mechanisms of Pterodactyloid Pterosaurs Pteranodon and several other genera of large pterodactyloid pterosaurs (e.g. Ornithocheirus, Quetzalcoatalus) exhibit a suite of skeletal features that severely constrained costally powered expansion of the thoracic cavity. These include: a) fusion of […]

SMITH, Kathleen: J. P. Hill and Katherine Watson’s studies of neural tube and neural crest development in marsupials. In the early part of the 20th century, James P. Hill and Katherine Watson initiated a study of the early development of the nervous system in marsupials. In this study, they used Hill’s superb collection of embryos […]

SWIDERSKI, D.L.: Independence of divergence and diversification in the evolution of scapula shape in squirrels: possible evidence of the lability of constraints. Lack of morphological diversity in a clade is often taken as evidence of constraints that restrict the magnitude or direction of change. Liberation from constraints is expected to result in both divergence and […]

NORIEGA, K.C.*; REGA, E.A.: Heretofore undocumented variation of an intrinsic hand muscle in a juvenile baboon Standard anatomical references for primate anatomy focus almost exclusively on adult morphology and rarely document the range of variability within structures. Dissection of the hands of a juvenile baboon (Papio sp.) demonstrates an accessory head to the m. opponens […]

HOMBERGER, D.G.: Functional Morphology of a Predator-Prey relationship: Australian Cockatoos and Woody Fruits A fresh analysis of the unique structure of the psittaciform quadrato-mandibular joint shows that this joint prevents a protraction of the mandible (in contrast to earlier interpretations), but allows lateral movements. Paradoxically, most parrots and cockatoos, which possess a psittaciform bill, do […]

SEARS, Karen: Adult morphological variation in mammalian limbs: Evidence for evolutionary constraint? Marsupials compose only six percent of living mammals and occupy a limited set of ecological niches. Traditionally, it has been assumed that low marsupial diversity is due their unique mode of reproduction constraining their evolution. Immediately after birth, marsupials, using only their precociously […]

PLUMMER, J T; CROLL, R P; Dalhousie University; Dalhousie University: The development and role of the larval nervous system in bivalve molluscs. A comprehensive approach was used to investigate the morphology of the larval nervous system (LNS) in bivalves and how its neuronal subcomponents function to regulate behaviour. The development of the LNS in the […]

STONE, Jon R; HALL, Brian K; Dalhousie University; Dalhousie University: Software Development: Computer Simulated Neural Crest Cell Migration Neural crest is a germ layer that emerges at the boundary between prospective neural and epidermal ectoderms in craniates during development. Neural crest disassociates via an epithelial-mesenchymal transition to migrate as individual cells or cellular populations and […]