Date of Degree
2009
Document Type
thesis
Degree Name
MS (Master of Science)
Department
Geoscience
First Advisor
Ann F. Budd
Abstract
Functional morphology and morphometric studies on various mammalian groups have shown marked differences in crania and mandible shape based on dietary preferences and feeding habits. In this study I used three-dimensional geometric morphometric methods to measure the shape of crania and mandibles of herbivorous and omnivorous mammals from three formations in northwestern Nebraska to explore the structure and disparity of ecosystems through time: The White River Group (Chadronian/Orellan/Whitneyan), the Arikaree Group (Arikareean), and the Ogallala Group (Hemingfordian/Barstovian/Clarendonian). Throughout the time period compromising these formations the climatic conditions were becoming more arid, grasslands were expanding and the large mammalian faunal compositions were shifting from browser dominated to grazer dominated. Relative warps analysis show a visible separation of faunas between the three formations that cannot be attributed to phylogeny in plots based on either the crania or the mandibles. Phylogenetic effects were taken into account using generalized least squares. These results indicate that it may be possible to differentiate fossil taxa from different formations and environments based on the shape of cranial and mandibular elements as well as to infer the environment or diet of a fossil if other unequivocal data are not available.
Pages
vi, 75
Bibliography
71-75
Copyright
Copyright 2009 Andy Darrell Grass
Recommended Citation
Grass, Andy Darrell. "Examining ecosystem structure and disparity through time using geometric morphometrics." thesis, University of Iowa, 2009.
http://ir.uiowa.edu/etd/367.
R code
SAS code.doc (21 kB)
SAS code
Crania canonical scores for first 28 relative warps.xls (38 kB)
Crania canonical scores for first 28 relative warps
Crania landmarks.txt (59 kB)
Crania landmarks
Crania partial warp scores.xls (133 kB)
Crania partial warp scores
Crania Procrustes coordinates.xls (147 kB)
Crania Procrustes coordinates
Crania relative warp Scores.xls (126 kB)
Crania relative warp Scores
Crania SAS output-PROC CORR between traditional lengths and .doc (32 kB)
Crania SAS output-PROC CORR between traditional lengths.doc
Crania SAS output-PROC DISCRIM on first 28 relative warps.doc (88 kB)
Crania SAS output-PROC DISCRIM on first 28 relative warps
Crania tradiational lengths and canonical scores.xls (111 kB)
Crania tradiational lengths and canonical scores
Crania wireframe protocol.txt (1 kB)
Crania wireframe protocol
Mandible canoncial scores of first 14 relative warps.xls (33 kB)
Mandible canoncial scores of first 14 relative warps
Mandibles landmarks.txt (21 kB)
Mandibles landmarks
Mandibles partial warp scores.xls (61 kB)
Mandibles partial warp scores
Mandibles Procrustes coordinates.xls (68 kB)
Mandibles Procrustes coordinates
Mandibles relative warp scores.xls (60 kB)
Mandibles relative warp scores
Mandibles SAS output-PROC CORR between traditional lengths a.doc (28 kB)
Mandibles SAS output-PROC CORR between traditional lengths.doc
Mandibles SAS output-PROC DISCRIM on first 14 relative warps.doc (68 kB)
Mandibles SAS output-PROC DISCRIM on first 14 relative warps
Mandibles SAS output-PROC PRINCOMP on partial warp scores.doc (60 kB)
Mandibles SAS output-PROC PRINCOMP on partial warp scores
Mandibles traditional lengths and canonical scores.xls (46 kB)
Mandibles traditional lengths and canonical scores
Mandibles wireframe protocol.txt (1 kB)
Mandibles wireframe protocol
Crania SAS output-PROC PRINCOMP on partial warp scores.doc (186 kB)
Crania SAS output-PROC PRINCOMP on partial warp scores