Vol. 8, Issue 9 (2019)

Author(s):
Sridevi P, Rajalakshmi K and SivaKumar M

Abstract:
The splanchnocranium consisted of single mandible, vomer and hyoid bones and paired quadrate, lacrimal, nasal, premaxilla, maxilla, Zygomatic (jugal), palatine and pterygoid bones. The ethmoid consisted of horizontal and perpendicular bony plates; the latter formed the interorbital septum caudally and joined the nasal septum rostrally. The lacrimal bone was larger and fused with the frontal and nasal bone; it had a frontal process in its caudal portion and a thin, pointed lacrimal process below. The nasal bone formed the dorsal and lateral boundaries of the nasal cavity, sutured rostrally with the frontal process of premaxilla and formed the upper beak. The Turbinates consisted of three cartilaginous nasal conchae. Premaxilla was V shaped and formed the major part of the upper beak. The maxilla was a V shaped small delicate bone which formed the caudal rim of the upper beak and part of bony palate. Zygomatic bone was thin rod like. The palatine bones were roughly triangular in shape. The pterygoid bone was a thin delicate bony plate situated on either sides of the Vomer. Vomer was an unpaired long tubular bone situated in the median plane. Quadrate bone consisted of a body and three processes otic, mandibular and orbital and was located between the neurocranium and maxillo-palatine apparatus. The mandible was U shaped with two slightly curved rami which fused rostrally and formed the Mandibular symphysis and enclosed a wide inter-mandibular space. Hyoid bone consisted of a rod shape unpaired body the basihyoid which at its rostral end had an articular surface for the single flat entoglossum.