References in periodicals archive ?
In Apalone spinifera, the elements of the neurocranium ossify between stages 19 and 23 (SHEIL, 2003), in Macrochelys teminckii between stages 21 and 24 (SHEIL, 2005), and in Chelydra serpentina (RIEPPEL, 1993; SHEIL; GREENBAUM, 2005) between stages 21 and 23, indicating that this is the period of longest duration in Podocnemis expansa, since it takes place between stages 19 and 24.
An isolated partially articulated segment of four dorsal fin pterygiophores are preserved near the posterior end of the neurocranium.
It is not feasible to present a probable phylogeny of the genus because more detailed anatomical studies of the four nominal species are needed, particularly the osteology of the caudal complex and the neurocranium, as well as a comparative study of their early ontogenic stages.
The neurocranium contains the anterior-most part of the frontals, lateral ethmoids, nasals, and posterior parts of the prenasals.