Document Type

Master's thesis

Date of Degree

2009

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

Additional Files

R code.doc (25 kB)
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

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