Figure 4 in Comparative ossification sequence and skeletal development of the postcranium of palaeognathous birds (Aves: Palaeognathae)

Figure 4. Graph of stage (Hamburger & Hamilton, 1951) of first occurrence of ossification for fore- and hindlimb elements for chicken, turkey, emu and rhea embryos. The order in which the elements are presented is standardized against the chicken sequence. Stage 40.5 is the same as stage 40+ in the text, whereas stage 45 represents elements that are ossified in the adult but unossified in the oldest embryo examined. The digit number is in roman numerals; the phalanges are numbered proximally to distally in arabic numerals.