19. The Myology of the Tree‐Shrew (Tupaia minor).

Forelimb Morphology of Tree Shrews

“…George (1977) has found the second head originating from pars spinohumeralis (see above) but not from the m. latissimus dorsi in the narrow sense. However the descriptions given for various species of tree shrews by Carlsson (1922) and Le Gros Clark (1924Clark ( , 1926 1.35, 1.36, 1.38, 1.39) is very well developed and has all the four heads recorded in mammals -caput longum, c. laterale, c. mediale, and c. accessorium, of which the latter two are poorly differentiated from each other. The caput longum is distinctly separated from others.…”

“…Distal to the ligament, the tendon bifurcates and inserts on a rudimentary prepollex and on the medial side of the proximal end of the first metacarpal. According to George (1977) the second branch of the tendon inserts not only on the first metacarpal but on the trapezium as well, but Le Gros Clark (1924Clark ( , 1926 reported that in Ptilocercus and Tupaia minor the insertion is restricted to the base of the first metacarpal.…”

“…Both scapular and vertebral portions insert by a common aponeurosis on the medial surface of the humerus distal to the insertion of the m. coracobrachialis brevis and close to the insertion of the m. latissimus dorsi. Sometimes the accessory portion is described as the separate muscle -m. spinohumeralis (Davis 1938;Le Gros Clark 1924). George (1977) regarded it as the part of the m. latissimus dorsi.…”

“…It inserts on the base of the greater tubercle of the humerus. Le Gros Clark (1924), Davis (1938), and Verma (1965) regarded the m. spinodeltoideus as the m. teres minor. Carlsson (1922) and Miller (1935) noted the absence of this muscle in the genus Tupaia.…”

Structural Diversity of the Extensor Digitorum Profundus Muscle Complex in Platyrrhini

“…However, the presence of the variants II and II-III in tree shrews [Le Gros Clark, 1924;Panyutina et al, 2015] provides evidence in favour of high variability of this structural characteristic within Euarchonta in general 3 . In the opinion of Dunlap et al [1985], based on data from Straus [1941], for all eutherian mammals the primitive distribution of tendons of m. extensor digiti secundi is digits II-IV.…”