Anatomical peculiarities of the broad-snouted caiman’s limb bones (Caiman latirostris)

Abstract

The aim of the study was the highlight of the specific characters of the limb bones in broad-snouted caiman, and for that, the investigations were conducted on the bones which were collected from a dead broad-snouted caiman that belonged to Bârlad Zoo. It was a male caiman, 24 years old. For the analysis, the bones were prepared by boiling and cleaning. It was noticed the particular conformation of the girdles, in case of the thoracic one, the scapula and the coracoid bone being almost similar developed, and both of them form the glenoid cavity to joint with humerus. It exist also an elongated interclavicular bone. The humerus is curved, ulna is more massive than the radius, between them existing a large radio-ulnar arcade, these aspects being similar to birds. There are 5 carpal bones, 3 in the proximal row, and 2 in the distal one, the radial carpal bone being merged with the intermediate one, resulting the most developed carpal bone. The thoracic metapodium includes 5 metacarpal bones, the 5th one being more reduced. The ilium is dorsally placed to ischium, the two bones participating to form the acetabular cavity (foramen). The pubis, more reduced, is cranially placed to ischium with which it articulates. The femur is very curved, and caudo-medially is highlighted the 4th trochanter. The fibula is well developed, but the tibia is more massive, and between them is a large interosseous space. The pelvic basipodium includes the calcaneum and astragalus, well developed, in the proximal row and two bones in the distal row. The 5th metatarsal bone is rudimentary, the others being well developed. The acropodium includes 5 digits for the thoracic limb and 4 in the pelvic one, the number of the phalanges having one more than the number of the digit, except the 5th digit of the thoracic limb. The conformation of the limb caiman bones is generally similar to other crocodiles.