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Evolutionary morphology of the rattlesnake style
Jesse M Meik1, André Pires-daSilva
1Department of Biology, The University of Texas at Arlington, Arlington, TX, USA. jmeik@uta.edu
BMC Evolutionary Biology
|February 12, 2009
Summary
Rattlesnake rattle evolution involved bone reallocation to form a bony style. This style
Area of Science:
- Evolutionary biology
- Herpetology
- Vertebrate anatomy
Background:
- The rattlesnake's unique rattling system evolved from generalized pitviper tails.
- A key modification is the bony style at the tail's end, previously unstudied phylogenetically.
Purpose of the Study:
- To investigate interspecific variation in rattlesnake bony style morphology.
- To examine the evolutionary context of style formation within rattlesnakes.
Main Methods:
- Analysis of skeletal material from 34 rattlesnake species.
- Utilized cleared and stained preparations and radiographs of preserved specimens.
Main Results:
- Evolutionary Principal Components Analysis showed bone reallocation from vertebrae to style formation.
- Basal species have small styles; two independent transitions to large, pronged styles occurred early in rattlesnake evolution.
- Distinct style morphologies in C. catalinensis and C. ericsmithi offer insights into rattle matrix evolution.
Conclusions:
- Rattle morphology variation correlates with bony style variation.
- Hypothesized that style morphology evolves as an integrated module linked to matrix morphology adaptation.
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