Morphological and Radiological Studies on the Skull of the Nile Crocodile (Crocodylus Niloticus)

Abstract

Background and Aim: Present study provides with more anatomical information on the structure and form of the bones forming the cranium of the Nile crocodile helps in understanding the interpretation of X ray images and surgical affection of the crocodile heads. Materials and Methods: The present study was conducted on six heads of the Nile crocodile (Crocodylus niloticus). The heads were removed from their bodies and prepared by hot water maceration technique. The bones of the skull were studied separately and identified by using a specific acrylic color for each bone. Results: The cranium of the crocodile composed of the cranial bones and the facial bones. The crocodile had four paired paranasal sinuses; the antorbital, the vomerine bullar, the pterygopalatine bullar and the pterygoid sinuses. The mandible of crocodile formed from six fused bones (articular, angular, suprangular, coronoid, splenial and dentary). The X ray images were applied for identifying the paranasal sinuses which their contribution to the morphological organization of the head. Conclusion: this results show a bony variation between the crocodile, mammals and also the birds that paves the way to the comparative anatomical and radiological studies.

Computerized Tomography, Radiological and Morphological Features on the Skull of Egyptian Owl (Bubo ascalaphus)

“…The cranium of owl composed of neurocranium and viscerocranium that separated by large two orbital cavities. A similar observation was reported by Choudhary et al (2020) in eagle and brown wood owl, Süzer et al (2018) in turkeys, Moselhy et al (2018) in ostrich, Nyari et al (2006) in house crow, Tahon (2013) in chickens, Shaker and El-Bably (2015) in crocodile. In agreement with the description of Choudhary et al (2020) in eagle and brown wooden owl; Moselhy et al (2018) in ostrich, Shaker and El-Bably (2015) in crocodile; the Occipital bones established by three parts; squamous, paired exooccipital and basioccipital ones.…”

“…A similar observation was reported by Choudhary et al (2020) in eagle and brown wood owl, Süzer et al (2018) in turkeys, Moselhy et al (2018) in ostrich, Nyari et al (2006) in house crow, Tahon (2013) in chickens, Shaker and El-Bably (2015) in crocodile. In agreement with the description of Choudhary et al (2020) in eagle and brown wooden owl; Moselhy et al (2018) in ostrich, Shaker and El-Bably (2015) in crocodile; the Occipital bones established by three parts; squamous, paired exooccipital and basioccipital ones. It enclosed a rounded foramen magnum as mentioned by (Ahmed and Al-Asadi, 2020 in turkey), although it was triangular in chickens (Tahon, 2013;McLelland, 1990), vertical oval (Choudhary et al, 2020 in brown wood owl;Süzer et al, 2018 in turkey).…”

“…The mandible comprised of two equal halves that formed mainly of five bones; dental, splenial, supra angular, angular and the articular bone, while Shaker and El-Bably (2015) confirmed the presence of another six bone (coronoid) in crocodile's mandible. The mandible fused rostrally forming the mandibular symphysis and had only single mandibular foramen which agreed with John et al (2016) in crow, contrarily in eagle and brown wood owl (Choudhary et al, 2020), ostrich (Moselhy et al, 2018), the mandible contained numerous rostral and caudal mandibular foramina.…”

“…Sphenoid bone constructed of presphenoid and basisphenoid, the first one combined rostrally with vomer bone and the second united caudally to basioccipital, that also reported by Ahmed and Al-Asadi (2020), Moselhy et al (2018), Tahon (2013. Although in crocodile Shaker and El-Bably (2015) reported that Sphenoid bone had another third part called alisphenoid.…”

Synchrotron “virtual archaeozoology” reveals how Ancient Egyptians prepared a decaying crocodile cadaver for mummification

“…These cut marks are associated with bones fractures. We also observed cut marks on the retroarticular processes of the mandible (Fig 3C, red arrows) [21].…”