Patagium The gliding membrane (patagium) of scaly-tailed squirrels consists of three distinct sections: the anterior propatagium extending from the shoulder along the forelimb, the large middle plagiopatagium spanning from forelimb to hindlimb, and the posterior uropatagium connecting the hindlimb to the proximal portion of the tail. Anomalurids are unique among all other gliding mammals in having a cartilaginous elbow spur, called the unciform element, which projects laterally from the ulna to support the anterior edge of the membrane during flight. This spur differs from the wrist-based styliform cartilage found in flying squirrels, having evolved from the triceps tendon rather than skeletal elements. The membrane attachment patterns vary between genera, with
Anomalurus species having more extensive connections to the hindlimbs compared to the smaller
Idiurus species. A specialized brush of stiff hairs on the membrane's dorsal surface just behind the elbow spur serves an aerodynamic function, passively thickening the wing's leading edge to improve airflow during gliding.
Tail Unlike the rougher-barked trees found in habitats of other gliding mammals, Anomalurids live on trees with relatively smooth bark like
Milicia excelsa that offer fewer natural grip points for claws. This has resulted in them evolving an adaption to aid them in the form a distinctive
keratinous scaly organ on the ventral surface of their tail base that gives scaly-tailed squirrels their common name. == References ==