26 research outputs found
TwoâHundred Million Years of Anuran BodyâSize Evolution in Relation to Geography, Ecology and Life History
Surprisingly, little is known about bodyâsize evolution within the most diverse amphibian order, anurans (frogs and toads), despite known effects of body size on the physiological, ecological and lifeâhistory traits of animals more generally. Here, we examined anuran bodyâsize evolution among 2,434 species with over 200 million years of shared evolutionary history. We found cladeâspecific evolutionary shifts to new bodyâsize optima along with numerous independent transitions to gigantic and miniature body sizes, despite the upper limits of anuran body size remaining quite consistent throughout the fossil record. We found a weak, positive correlation between a speciesâ body size and maximum latitude and elevation, including a dearth of small species at higher elevations and broader latitudinal and elevational ranges in larger anurans. Although we found modest differences in mean anuran body size among microhabitats, there was extensive overlap in the range of body sizes across microhabitats. Finally, we found that larger anurans are more likely to consume vertebrate prey than smaller anurans are and that species with a freeâswimming larval phase during development are larger on average than those in which development into a froglet occurs within the egg. Overall, anuran body size does not conform to geographic and ecological patterns observed in other tetrapods but is perhaps more notable for variation in body size within geographic regions, ecologies and life histories. Here, we document this variation and propose target clades for detailed studies aimed at disentangling how and why variation in body size was generated and is maintained in anurans