Abstract
-Significant differences exist in adult carapace lengths among the four species of North American tortoises (Gopherus spp.). However, after measures of whole shell and scute dimensions are adjusted for these size differences, shape is more similar between the largest species, G. favomarginatus, and the smallest species, G. berlandieri, than with either of the intermediate-sized species, G. polyphemus and G. agassizii. Recent data based on an analysis of mitochondrial DNA of North American tortoises provide a phylogeny of the four extant species. A phenogram based on a multivariate analysis of 31 scute and shell measurements of North American tortoises is not concordant with a phenogram based on genetic data, although relationships among three major populations of G. agassizii are the same. Morphometric data are also not concordant with a matrix based on measures of precipitation and temperature, but are significantly correlated with a matrix based on growth variables (R2 = 0.74, P = 0.029). Other environmental parameters may affect shape of shells.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
