Numeric and morphological studies of the African lion (Panthera leo leo) pectoral limb.

BACKGROUND: The Importance of the appendicular skeleton in the conformation, shape and physiology of wild animals especially carnivores for adaptation and survival cannot be overemphasized, as limited and obsolete information on the bones of the forelimb necessitated this study. Matured adult African lions (Male and female) that weighed 173 kg and 112 kg were obtained at different times after post mortem examinations of their carcasses. Bone preparation was achieved via cold water maceration after proper skin and muscle removal to a barest minimum. RESULTS: The acromion process of the scapula consisted of a ventral hamate and caudal suprahamate processes. The Clavicle was absent in this species. The musculospiral groove of the humerus was more or less absent while its supracondyloid foramen and crest were positioned above the medial condyle and lateral condyle respectively. The radio-ulna presented a twisted appearance with the radius slightly curved thereby creating an extensive interosseous space that spanned its entire length. The seven (7) carpal bones were uniquely arranged in two rows while the 5 metacarpals anchored 5 digits with 3 phalanges except the first with 2 phalanges each. Two sesamoid bones were located on the ventral surface of each Metacarpophalangeal joint. None was seen on its dorsal surface. The 3rd phalanx had a unique appearance with a crescent plate projecting from the ventral cavity. The average total number of bones constituting the pectoral limb was 80. CONCLUSION: Numerical information and detailed anatomical features of the pectoral limb bones of the African lion (Panthera leo leo) have added some valuable literature to science. This further serves as a baseline data for future scientific exposition on this species.

Axial skeletal morphological studies on the helmeted Guinea fowl (Numida meleagridis).

This study on the morphological features of bones of the helmeted guinea fowl (Numidia meleagridis) specifically the axial skeleton was conducted for documentation and valuable information on differences when compared with other species of the same order. Ten (10) Helmeted guinea fowls (5 females and 5 males) with an average weight of 3.0 kg were euthanized via jugular vein severance with bone preparation achieved via the use of insect larvae. The skull presented an elongated structure made up of paired and unpaired flat, short and long bones with distinctive features. The frontal bone projected caudodorsally to form a horn like structure, the frontal process at its middle while the vomer was absent. The cervical vertebrae were 14 in number starting from the first (Atlas) to the last vertebra without a rib. Specific distinguishing features were evident in the Atlas, Axis, 3rd to 5th, 6th to 11th and 12th to 14th cervical vertebrae. The thoracic vertebrae presented 7 bones comprising the 1st single free vertebra; notarium (fused 2nd to 5th), 6th single free vertebra and the last 7th vertebrae that fused with the synsacrum which was an ankylosis of the lumbar and sacral vertebrae. The caudal vertebrae were 7 with the last; the pygostyle being distinct in appearance. The ribs were 7 pairs, of which the first two were asternal while the remaining five were sternal and consisted of proximal vertebral and distal sternal portions. The curved uncinate process articulated to the caudal border of the 2nd and vertebral portions of the 3rd to 5th ribs. The guinea fowl proved to be a carinate by presenting a single sternum with dorsolateral processes and a ventral carina. In conclusion, this study revealed that except for the skull, the axial skeleton of the Helmeted Guinea fowl presented similarities to that of the domestic fowl (Gallus domesticus).

Morphological and morphometric studies on the axial skeleton of the sitatunga (Tragelaphus spekii gratus).

BACKGROUND: Anatomical features of the skeleton of wild animals contribute largely to their adaptation. A dearth of information on the skeletal anatomy of the sitatunga (Tragelaphus spekii gratus) necessitated this study. Two adult sitatunga carcasses weighing 54 kg and 57 kg were obtained after post-mortem examination. Bone preparation was achieved through cold water maceration protocol. RESULT: The tympanic bulla was elongated and massive, resulting in the rudimentary appearance of the styloid and muscular processes of the temporal bone. The lacrimal bone had a somewhat triangular presentation with the lacrimal foramen on the caudal border of the facial surface while its dorsal border formed the lateral margin of the frontal sinus. There was no observable lacrimal fossa on this facial surface of the lacrimal bone. The facial tubercle was absent. The vertebral column formula was C7 T13 L6 S4 C10-14, and the atlas dorsal median tubercle was smooth, devoid of ridges. The spinous process of the axis extended the entire arch length to hang little above the odontoid process. The thoracic spinous processes were oriented dorso-caudally from T1 to T11; spinous process of T12 was vertical, while that of T13 was oriented dorso-cranially. The length of the transverse process of L1 and L6 were the same, and smaller than the length of those of L2-L5. There was incomplete fusion of sacral spinous processes. Three dorsal and ventral sacral foramina were identified laterally on each side of the vertebrae. The ribs were 26 in number (13 pairs). The sternum was comprised of 5 sternabrae separated by intersternal cartilage. The average number of bones of the axial skeleton was 75. Morphometric in formation included the length of skull, mandible and ribs; body length of vertebrae and spinous process length and height of the vertebrae. CONCLUSION: This study recorded anatomical features and biometric information on axial skeletal bones of the Sitatunga (Tragelaphus spekii gratus) thereby providing baseline data for future biomedical, archaeological and comparative skeletal anatomical studies.

Morphology of the spinal nerves from the cervical segments of the spinal cord of the African giant rat (Cricetomys Gambianus).

This study provides detailed description of the gross morphology and distribution of the nerves arising from the cervical segments of the spinal cord of the African Giant Rat (AGR). Two (2) AGRs were used for this study. The rats were euthanized using halothane. The skin and superficial fascia were removed, and dissection of the muscles in the cervical region and thoracic limbs was carried out. The vertebral canal was opened by means of a rongeur. Eight (8) pairs of spinal nerves (C1-C8) arose from the cervical segments of the spinal cord of the AGR by means of dorsal and ventral roots which merged lateral to the spinal cord to form spinal nerves. Each cervical spinal nerve divided into a dorsal and ventral ramus just before exiting the intervertebral foramen. The dorsal rami divided into medial and lateral branches distributed on the medial faces of the semispinalis and splenius muscles, respectively. The ventral rami of C1, C2 and a branch from C3 interconnected to form the cervical plexus from which branches were distributed to the M. cleidomstoideus, M. cleidooccipitalis, M. occipitoscapularis, M. omotransversarius and M. trapezius. The ventral rami of C5, C6, C7, C8 and T1 (first thoracic spinal nerve) interconnected to form the brachial plexus. The cervical spinal nerves gave rise to dorsal rami or primary branches that supplied the skin and muscles of the dorsal part of the neck and the ventral primary branches which interconnected to give rise to the cervical plexus and brachial plexuses of the AGR.