Event Title

A Comparative Study of Eggshell Pore Morphology of Palaeognath Birds

Graduation Year

2016

Location

Center for Natural Sciences, Illinois Wesleyan Universtiy

Start Date

18-4-2015 2:00 PM

End Date

18-4-2015 3:00 PM

Description

Avian eggshell pores, which allow gas exchange to and from the embryo, vary in size and structure (e.g., diameter, branching pattern, shape, abundance, and dispersion) among species. Previous studies have indicated that eggshell microstructures can contribute to the development of evolutionary hypotheses (phylogenies) of avian taxa. We are focusing on the Palaeognath taxon, which includes the extinct flightless Ratites (Elephant Birds and Moas), the extant flightless Ratites (i.e., Ostriches, Emus, Rheas, Kiwis, Cassowaries), and the extant flighted Tinamous. The purpose of our study is to evaluate whether eggshell pore morphologies are phylogenetically informative characters for Palaeognath birds. We are using a polyurethane-based resin to make three-dimensional corrosion casts of eggshell pore spaces. Preliminary data from the casts of Elephant Bird pore spaces indicate that in one third of the observed fragments, bifurcated branching exists in the palisade layer (the region closest to the external surface). Unbranched pores were cylindrical based on a comparison of pore diameters in the upper, middle, and lower regions.

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Apr 18th, 2:00 PM Apr 18th, 3:00 PM

A Comparative Study of Eggshell Pore Morphology of Palaeognath Birds

Center for Natural Sciences, Illinois Wesleyan Universtiy

Avian eggshell pores, which allow gas exchange to and from the embryo, vary in size and structure (e.g., diameter, branching pattern, shape, abundance, and dispersion) among species. Previous studies have indicated that eggshell microstructures can contribute to the development of evolutionary hypotheses (phylogenies) of avian taxa. We are focusing on the Palaeognath taxon, which includes the extinct flightless Ratites (Elephant Birds and Moas), the extant flightless Ratites (i.e., Ostriches, Emus, Rheas, Kiwis, Cassowaries), and the extant flighted Tinamous. The purpose of our study is to evaluate whether eggshell pore morphologies are phylogenetically informative characters for Palaeognath birds. We are using a polyurethane-based resin to make three-dimensional corrosion casts of eggshell pore spaces. Preliminary data from the casts of Elephant Bird pore spaces indicate that in one third of the observed fragments, bifurcated branching exists in the palisade layer (the region closest to the external surface). Unbranched pores were cylindrical based on a comparison of pore diameters in the upper, middle, and lower regions.