plosone-phylo
pone.0031781.g001
Phylogenetic hypothesis for extant Crocodylia showing variation in rostral proportions.
The cladogram is based on reanalysis (see Materials and Methods) of molecular data from Gatesy and colleagues [2] using maximum likelihood and non-parametric rate-smoothing with branch lengths proportional to time. Lineages shown in blue represent caiman (a–e) and alligators (f,g) ( = Alligatoridae), and those in green crocodiles (h–t) and gharials (u,v) ( = Crocodylidae+Gavialidae). The Yacare caiman, Caiman yacare is not shown for it was not utilized in the Gatesy et al. [2] analysis. Dorsal views of heads are modified from Wermuth and Fuchs [53] and standardized to the same length to show relative differences in rostral form. Bracketed numbers following taxon names are the mean rostral proportions or RP ( = mid-rostral width/snout length) for each taxon from our study. Phylogenetic Independent Contrasts were performed on these 22 species; however, bite force, tooth pressure, and morphometric measurements and subsequent TIPs analyses were performed for all 23 extant taxa, including Caiman yacare.
pone.0031781.g001
Phylogenetic hypothesis for extant Crocodylia showing variation in rostral proportions.
The cladogram is based on reanalysis (see Materials and Methods) of molecular data from Gatesy and colleagues [2] using maximum likelihood and non-parametric rate-smoothing with branch lengths proportional to time. Lineages shown in blue represent caiman (a–e) and alligators (f,g) ( = Alligatoridae), and those in green crocodiles (h–t) and gharials (u,v) ( = Crocodylidae+Gavialidae). The Yacare caiman, Caiman yacare is not shown for it was not utilized in the Gatesy et al. [2] analysis. Dorsal views of heads are modified from Wermuth and Fuchs [53] and standardized to the same length to show relative differences in rostral form. Bracketed numbers following taxon names are the mean rostral proportions or RP ( = mid-rostral width/snout length) for each taxon from our study. Phylogenetic Independent Contrasts were performed on these 22 species; however, bite force, tooth pressure, and morphometric measurements and subsequent TIPs analyses were performed for all 23 extant taxa, including Caiman yacare.