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Dissection and Flat-mounting of the Threespine Stickleback Branchial Skeleton
Published on: May 7, 2016
Histological variability in fossil and recent alligatoroid osteoderms: systematic and functional implications.
Michael E Burns1, Matthew K Vickaryous, Philip J Currie
1Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada. mburns@ualberta.ca
Journal of Morphology
|February 6, 2013
Summary
Studying osteoderms in modern and extinct alligators reveals that their bone structure variations are due to physical constraints, not evolutionary or taxonomic differences. This finding aids in understanding extinct reptile fossils.
Area of Science:
- Paleontology
- Comparative Anatomy
- Histology
Background:
- Morphological variation studies in extinct species are often limited by small sample sizes.
- Extant taxa can provide larger sample sizes to inform studies of extinct relatives.
Purpose of the Study:
- To quantitatively and qualitatively examine histological and morphological variation in osteoderms from extant and extinct alligatoroids.
- To determine the factors driving observed variations in osteoderms.
Main Methods:
- Comparative analysis of osteoderms from extant and extinct alligatoroid specimens.
- Quantitative and qualitative examination of histological and morphological features.
- Statistical analysis to correlate differences with size, shape, and other factors.
Main Results:
- Statistically significant differences in osteoderms were correlated with changes in size and shape.
- These osteoderm variations were independent of body position, taxonomy, or evolutionary lineage.
- Histological variation is attributed to morphological constraints of the osteoderms themselves, not taxonomic distinctions.
Conclusions:
- Osteoderm morphology and histology in alligatoroids are primarily influenced by inherent structural constraints.
- This understanding has implications for interpreting histological characters in extinct archosaur groups lacking direct modern analogues.
- The study highlights the utility of extant taxa for understanding extinct species' morphology.
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