The structure and development of the skull of Costa Rican plethodontid salamanders (Amphibia: Urodela).
We describe the structure of the skulls of the Costa Rican plethodontid salamanders Bolitoglossa subpalmata, Oedipina uniformis and Nototriton abscondens, and the characteristic sequences of development and ossification of the bony elements resulting from direct development using mainly cleared and stained specimens. Significant differences between the species studied are observed. N. abscondens possesses the broadest premaxillary pars dentalis and O. uniformis the narrowest one. The premaxillary dorsal processes are fused over their rostral third only in B. subpalmata; over half their extention in N. abscondens and almost completely in O. uniformis. A prefrontal is always present in N. abscondens; it is hidden underneath the nasal or missing in B. subpalmata, and it is always absent in O. uniformis. The skull bones, with the exception of the orbitosphenoid, develop and ossify sequentially from caudal to rostral in these directly developing species. A more massive pars dentalis of a generally narrower premaxillary are found as typical characters in males.
Ehmcke
J
J
Institut für Spezielle Zoologie und Vergleichende Embryologie, Westfälische Wilhelms-Universitat, Münster, Germany.
Clemen
G
G
D000375:Aging; D000818:Animals; D003364:Costa Rica; D005260:Female; D008297:Male; D012727:Sex Characteristics; D012886:Skull / Q000033:anatomy & histology* / Q000254:growth & development*; D013045:Species Specificity; D014562:Caudata / Q000033:anatomy & histology* / Q000254:growth & development