ANATOMICAL ASPECTS OF THE CAUDAL THIGH MUSCLES OF COATI (Nasua nasua, LINNAEUS 1766)

The coatis (N. nasua) are carnivores Procyonidae family, found mainly in forested habitats, from northern Colombia to northern Argentina. Generalist omnivores, they feed both on the ground as in trees. By ingesting mainly fruits, they are potential seed dispersers, participating in forest dynamics. The habit of climbing trees to feed makes their hindlimbs much more required and versatile than those of canids, of which they evolutionarily diverged but still share the same Suborder. Thus, this study examined the anatomical aspects of the muscles that integrate the caudal group of the thigh of coatis, which had its general aspects, location, shape, origin, insertion, syntopy and functions evaluated. Five adult animals (two females and three males) provided by IBAMA-GO (License: 98/2011) were used in this research. They were fixed with 10% formaldehyde solution and dissected after a minimum period of 72 hours after fixation. The muscles which comprise the caudal group of the thigh of coatis are the m. semitendinosus, the m. semimembranosus, m. biceps femoris and m. abductor cruris caudalis. The semitendinosus has two heads, long (lateral) and short (medial), while the semimembranosus is incompletely divided into cranial and caudal parts. The biceps femoris muscle has only one head. The ligamentum sacrotuberale is absent and the abductor cruris caudalis muscle originates from the deep surface of the gluteofemoral muscle and adjacent part of the gluteus superficialis. The abilities acquired by coatis as they distanced from canids becoming climbers have been accompanied by anatomical adaptations in the structure of the caudal muscles of the thigh, which are characterized by modifications in their origins, insertions or even relating to their length or their muscle belly divisions.