The phylogeny of the red panda (Ailurus fulgens): evidence from the forelimb

Abstract

Within the order Carnivora, the phylogeny of the red panda (Ailurus fulgens) is contentious, with morphological and molecular studies supporting a wide range of possible relationships, including close ties to procyonids, ursids, mustelids and mephitids. This study provides additional morphological data, including muscle maps, for the forelimb of Ailurus, based on the dissection of four cadavers from the National Zoological Park, Washington, DC, USA. The red panda forelimb is characterized by a number of primitive features, including the lack of m. rhomboideus profundus, a humeral insertion for m. cleidobrachialis, the presence of mm. brachioradialis, articularis humeri and coracobrachialis, a single muscle belly for m. extensor digitorum lateralis with tendons to digits III-V, four mm. lumbricales, and the presence of mm. flexor digitorum brevis manus, adductores digiti I, II and V, and abductor digiti I and V. Red pandas resemble Ailuropoda, mustelids and some procyonids in possessing a soft tissue origin of m. flexor digitorum superficialis. In addition, red pandas are similar to ursids and procyonids in having a variable presence of m. biceps brachii caput breve. Furthermore, Ailurus and some ursids lack m. rhomboideus capitis. The forelimb muscle maps from this study represent a valuable resource for analyzing the functional anatomy of fossil ailurids and some notes on the Miocene ailurid, Simocyon batalleri, are presented.

Forelimb muscle architecture and myosin isoform composition in the groundhog (Marmota monax)

“…A long head originating on the scapula is the typical mammalian condition and is a feature consistent among climbers (Stalheim-Smith, 1984;Thorington et al, 1997;Fisher et al, 2009). However, the presence of additional scapular heads of the triceps as observed in badgers (Moore et al, 2013), skunks (Ercoli et al, 2014) and armadillos (Windle and Parsons, 1899) is not a feature observed in climbers, although the origin of the long head on the scapula may be broad (Harrison, 1882).…”

“…Climbing mammals have relatively less intrinsic muscle mass for elbow extension and digital flexion (Gambaryan, 1974;Taylor, 1978;Moore, 2011), and variation in relative extrinsic muscle mass is largely explained by the absence of muscles. For example, the rhomboideus capitis (and profundus) is commonly absent (Fisher et al, 2009), which may indicate less ability to protract the limb and stabilize the scapula cranially. Climbers invest in large pectoralis muscles as do scratch-diggers, but they may show relatively greater division of the pectoralis superficialis and profundus (Harrison, 1882;Julik et al, 2012) for strong adduction and increased grasping control of the forelimb during climbing.…”

“…We previously found the size-specific mass of the teres major in the opossum to be significantly higher than that of the badger (Moore, 2011), and this may be an alternative strategy to increase the applied flexor moment in more generalized climbers. Moreover, climbing mammals often have both an articularis humeri and a welldeveloped coracobrachialis (Fisher et al, 2009), indicating the need for shoulder joint stability during arboreal maneuvering, and additionally, emphasizing the importance of limb adduction.…”

“…However, the presence of additional scapular heads of the triceps as observed in badgers (Moore et al, 2013), skunks (Ercoli et al, 2014) and armadillos (Windle and Parsons, 1899) is not a feature observed in climbers, although the origin of the long head on the scapula may be broad (Harrison, 1882). Carnivores that climb often have a second accessory head associated with the medial head (Fisher et al, 2009;Julik et al, 2012). Multiple accessory heads suggest greater joint position control for precise movements on narrow substrates, whereas two biarticular heads of the triceps can substantially increase of the flexor moment applied at the shoulder joint for retraction of the forelimb to excavate earth (Moore et al, 2013).…”

POLYCYSTIC KIDNEYS IN THE RED PANDA (AILURUS FULGENS)

“…6 In the wild, its average lifespan is 8 to 10 yr, whereas in captivity is 13.4 yr. 10 Polycystic kidney disease (PKD) has been reported in humans 7,11,16 and in various animal species such as domestic cats 1,3,4 and dogs. 12,14 In domestic cats, the disease is more prevalent in Persian cats; 4 in dogs, it is more prevalent in terrier breeds.…”