Macro–anatomical and morphometric studies of the Grasscutter (thryonomysswinderianus), forelimb skeleton

Onwuama Kenechukwu Tobechukwu*, Ojo Samuel Adeniyi, Hambolu Joseph Olajide, Dzenda Tavershima and Salami Oluwoye Sulaiman 

Accepted 29 September, 2014.

Citation: Onwuama KT, Ojo SA, Hambolu JO, Dzenda T, Salami OS (2015). Macro–anatomical and morphometric studies of the Grasscutter (thryonomysswinderianus), forelimb skeleton. International Journal of Veterinary Science and Animal Husbandry 2(1): 006-012.


Copyright: © 2015 Onwuama et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are cited. 


The Forelimb of the Grasscutter (Thryonomysswinderianus) was studied using 12 adult rats of both sexes with mean weights of 5167±0.2023kg and 0.8167±0.1276kg for male and female respectively. Correlation coefficient between length of each bone segment and weight of each animal revealed statistical significance (P < 0.05) in all bone segments except the manus when both sexes (n = 12) were considered signifying a positive relationship between weight of the animal and its bone size. The average total number of bones in the forelimb of the rat is 96 bones. Sexual dimorphism was not noticed. The bones of the forelimb revealed significant differences and similarities in morphology to that of other rodents and domestic animals. The Scapula presented a prominent triangular shaped metacromion and acromion process, the Humerus presented well defined head and distinct deltoid tuberosity protruding from the midshaft. The ulna and radius fuses proximally and distally leaving an expansive interosseus space. There were 8 irregularly shaped carpal bones arranged 3 proximally and 5 distally. Metacarpal and digital bones are 5 on each forelimb with the first and fifth greatly reduced with each digit presenting 3 phalanges.

Key words: Grasscutter, forelimb, bones, Macro-Anatomical