_Developmental Cranial Morphology of Smilisca baudini_
The following description of development of the skull of _Smilisca baudini_ is based on the examination of 12 cleared and stained specimens. In table 3 the cranial bones are listed in the left hand column in the approximate order of their appearance in the young frogs. Across the top of the table selected specimens designated by developmental stage or snout-vent length are listed. It should be noted that although each individual, from left to right, has an increasing number of ossified bones, the correlation with increasing size is imperfect; the precise ages of the individuals are unknown.
The first bones to appear are the septomaxillaries, frontoparietals, part of the exoccipital, and the parasphenoid in developmental stage 40. The frontoparietals are represented by two slender ossifications dorsomedial to the orbits; the septomaxillaries are present as small ossifications anterior to the nasal capsules (Pl. 1A). The parasphenoid is present as a faint median ossification, and the exoccipital shows some ossification.
Table 3.--The Order of Occurrence of Cranial Ossifications in the Skull of Smilisca baudini. Where Numbers Are Divided by a Slash Mark, the Left and Right Symbols Correspond to the Left and Right Sides of the Skull, Respectively.
=====================+=====+=====+=====+=====+=====+=====+==== Bone |Stage|Stage|12.6 |13.9 |32.0 |27.0 |20.1 | 40 | 44 | mm. | mm. | mm. | mm. | mm. ---------------------+-----+-----+-----+-----+-----+-----+---- Frontoparietal | X | X | X | X | X | X | X Parasphenoid | X | X | X | X | X | X | X Septomaxillaries | X | X | X | X | X | X | X Exoccipitals | X | X | X | X | X | X | X Squamosals | -- | X | X | X | X | X | X Premaxillaries | -- | X | X | X | X | X | X Maxillaries | -- | X | X | X | X | X | X Nasals | -- | -- | X | X | X | X | X Pterygoids | -- | -- | X | X | X | X | X Vomers | -- | -- | -- | X | X | X | X Palatines | -- | -- | -- | X | X | X | X Quadratojugals | -- | -- | -- | X | X | X | X Ethmoid | -- | -- | -- | -- | X | X | X Columellas | -- | -- | -- | -- | X | X | X Supraorbital Flanges | -- | -- | -- | -- | -- | X | X Proötics | -- | -- | -- | -- | -- | -- | X Vomerine Teeth | -- | -- | 1/1 | 4/3 | 5/5 | 3/3 | 5/4 Maxillary Teeth | -- | 0/7 | 3/5 | 6/5 |30/31|30/26|37/36 Premaxillary Teeth | -- | 2/4 | 3/3 | 5/5 | 7/6 | 8/6 | 8/7 ---------------------+-----+-----+-----+-----+-----+-----+----