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Full-Text Articles in Life Sciences
First Major Appearance Of Brachiopod-Dominated Benthic Shelly Communities In The Reef Ecosystem During The Early Silurian, Cale A.C. Gushulak
First Major Appearance Of Brachiopod-Dominated Benthic Shelly Communities In The Reef Ecosystem During The Early Silurian, Cale A.C. Gushulak
Electronic Thesis and Dissertation Repository
The early Silurian reefs of the Attawapiskat Formation in the Hudson Bay Basin preserved the oldest record of major invasion of the coral-stromatoporoid skeletal reefs by brachiopods and other marine shelly benthos, providing an excellent opportunity for studying the early evolution, functional morphology, and community organization of the rich and diverse reef-dwelling brachiopods. Biometric and multivariate analysis demonstrate that the reef-dwelling Pentameroides septentrionalis evolved from the level-bottom-dwelling Pentameroides subrectus to develop a larger and more globular shell. The reef-dwelling brachiopods in the paleoequatorial Hudson Bay Basin were more diverse than contemporaneous higher latitude reef-dwelling brachiopod faunas, with ten distinct …
Assortative Mating But No Evidence Of Genetic Divergence In A Species Characterized By A Trophic Polymorphism, Scott F. Coborne, S R. Garner, Fred Longstaffe, Bryan D. Neff
Assortative Mating But No Evidence Of Genetic Divergence In A Species Characterized By A Trophic Polymorphism, Scott F. Coborne, S R. Garner, Fred Longstaffe, Bryan D. Neff
Earth Sciences Publications
Disruptive selection is a process that can result in multiple sub-groups within a population, referred to as diversification. Foraging related divergence has been described in many taxa, but many questions remain about the contribution of such divergence to reproductive isolation and potentially sympatric speciation. Here we use stable isotope analysis of diet and morphological analysis of body shape to examine phenotypic divergence between littoral and pelagic foraging ecomorphs in a population of pumpkinseed sunfish (Lepomis gibbosus). We then examine reproductive isolation between ecomorphs by comparing the isotopic compositions of nesting males to eggs from their nests (a proxy for maternal …
Dentine Oxygn Isotopes (Δ18o) As A Proxy For Odontocete Distributions And Movements., Cory J.D. Matthews, Fred J. Longstaffe, Steven H. Fergispm
Dentine Oxygn Isotopes (Δ18o) As A Proxy For Odontocete Distributions And Movements., Cory J.D. Matthews, Fred J. Longstaffe, Steven H. Fergispm
Earth Sciences Publications
Spatial variation in marine oxygen isotope ratios ( δ18O) resulting from differential evaporation rates and precipitation inputs is potentially useful for characterizing marine mammal distributions and tracking movements across δ18O gradients. Dentine hydroxyapatite contains carbonate and phosphate that precipitate in oxygen isotopic equilibrium with body water, which in odontocetes closely tracks the isotopic composition of ambient water. To test whether dentine oxygen isotope composition reliably records that of ambient water and can therefore serve as a proxy for odontocete distribution and movement patterns, we measured δ18O values of dentine structural carbonate (δ18 …