Comparative Gross Anatomical Studies on Pelvic Limb Long Bones of Crested Serpent Eagle (Spilornis cheela) and Brown Wood Owl (Strix leptogrammica)

Abstract

There is no previously reported information on the morphological characteristics of pelvic limb long bones (femur, tibiotarsus and tarsometatarsus) in crested serpent eagle and brown wood owl. Thus, this study aimed to evaluate morphological and biometrical characteristics of pelvic limb long bones in crested serpent eagle and brown wood owl. The femur consisted of a curved shaft and two extremities. The shaft was wider proximally and distally and presented medial, lateral, anterior and lateral surfaces. The anterior, medial and lateral surfaces were smooth and continuous in both the species. An intermuscular line called linea aspera was present on the anterior and posterior surfaces in both the species. The proximal and distal extremities of the femur were almost of equal size. The proximal extremity presented a distinct, hemispherical head which was located in the level of the trochanter major in both the species. The distal extremity furnished a trochlea anteriorly for patella and medial, lateral condyles posteriorly for tibiotarsus bone. The patella was small and triangular and consisted of two surfaces, two borders, a base and an apex in both the species. Tibiotarsus was the longest bone in both the species which was formed by the fusion of distal extremity of the tibia with the proximal row of the tarsal bones. The proximal and distal extremity of the tibiotarsus consisted of medial and lateral condyles. In both the species, the fibula was a rod-shaped bone and reached up to distal third of the lateral border of the tibiotarsus. The tarsometatarsus was a long bone but smaller than tibiotarsus in both the species. Various biometrical parameters of the pelvic limb long bones were more in the crested serpent eagle as compared to the brown wood owl due to species differences.