Hindlimb myology of the kinkajou (Potos flavus )
Authors: Fields Shelby , Smith Heather F. 
Published: June 2021

The kinkajou (Potos flavus) is a common exotic pet in the United States, and is also found in many zoo collections. However, basic information about its anatomy, which is essential for proper veterinary care, is poorly documented. Captive kinkajous often suffer from metabolic bone disorders resulting from inappropriate captive diet. Unfortunately, these bone diseases are difficult to diagnose due to a lack of understanding of baseline anatomy and available references, such as normal radiographs. There is also little understanding of kinkajou locomotion, which is important for understanding how they interact with their environment. The kinkajou can plantarflex and invert its pes (hindfoot) around multiple ankle and pes joints in order to fully reverse the pes 180°; however the myological and osteological adaptions that facilitate this behavior are unclear. Well‐developed plantarflexor and invertor muscles were recently hypothesized in species exhibiting hindfoot reversal. However, recent studies of other procyonids do not support this hypothesis.

To address the issue of the lack of understanding of basic kinkajou anatomy and its locomotor behaviors, the left and right hindlimbs of an adult male kinkajou were dissected. A detailed description, and documentation of the hindlimb muscles in P. flavus was conducted. Here, we present the first comprehensive review of the muscular anatomy of the hindlimb of P. flavus including detailed anatomical description, muscle maps of the pelvis, long bones, and pes, and comparisons to other documented species of the Carnivoran order.

Our dissections revealed that the anatomy of the hindlimb muscles was generally consistent with previous descriptions of other carnivoran taxa, although we observed a few interesting differences. In the thigh, the kinkajou had three bellies of m. semimembranosus, in contrast to two bellies in another procyonid, the ringtail (Bassariscus astutus), giant panda, and the domestic dog. The only other taxa with three bellies were the lesser grison and red panda. In the quadriceps femoris group, the kinkajou most closely resembled the red panda; however, it also shared some similarities in the quadriceps femoris with the ringtail and lesser grison. In the leg, the kinkajou closely resembles the domestic dog and lesser grison in the morphology of the m. gastrocnemius. In m. popliteus, the kinkajou most closely resembles the ringtail.

Having this baseline understanding of kinkajou hindlimb functional anatomy, can provide insight into adaptations for its unique locomotor style. This understanding also has implications for proper husbandry by lending itself to the development of more exceptional habitats and enrichments for captive specimens and creating awareness for how any potential changes to environmental habitat could affect their health and well‐being.

Support or Funding Information

This study was funded by the Department of Biomedical Sciences, Midwestern University.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.