title: [Crucial stages of embryogenesis of Rana arvalis: Part 2. Development of head structures].
abstract: Analysis of the dynamics of variation in developing head structures of moor frog (R. arvalis) tadpoles has made it possible to reveal periods in which the limits of variation in relevant traits are narrowed. In the course of individual development, these so-called crucial periods for certain traits are followed by such periods for other traits. However, crucial stages for some head structures have not been revealed, which can be explained by a relatively short period of development considered in the study. Analysis of individual variation at later stages may provide the possibility to identify crucial periods for these structures.
authors: E A
authors: EA
authors: Severtsova
authors: A S
authors: AS
authors: Severtsov
mesh_terms: D000818:Animals; D004625:Embryo, Nonmammalian; D006257:Head / Q000196:embryology*; D011898:Ranidae / Q000196:embryology*