Size and shape of eggs of Neognathae: effects of developmental mode and phylogeny

Canadian Journal of Zoology, e-First Articles. We evaluated the variation in absolute size and shape of birds ’ eggs and the effects of developmental mode and phylogenetic relatedness on these traits. Eggs were characterized by length, diameter, and three indices of egg shape. Indices of egg shape were calculated as the ratio of radii that described the curvature of pointed end (cloacal zone), blunt end ( infundibular zone), and lateral zone to egg diameter. We found that eggs shape was less variable than the absolute size of eggs. Index of the cloacal zone was the most changeable and index of the infundibular zone was very conservative. Size and shape of eggs could be better explained with phylogene tic relatedness than developmental mode.

Source: Canadian Journal of Zoology - February 26, 2017 Category: Zoology Source Type: research