The semifossorial function of the forelimb in the common rice tenrec (Oryzorictes hova) and the streaked tenrec (Hemicentetes hemispinosus).
The forelimb muscles of the two semifossorial species of Tenrecidae (Oryzoryctinae: common rice tenrec; and Tenrecinae: streaked tenrec) were compared macroscopically with those of the unspecialized terrestrial-arboreal species, the Talazac long-tailed tenrec. The structure of the hand was also observed using three-dimensional reconstructed images from computed tomography data. The two semifossorial species had similar muscle weight ratios in the lateral and long heads of M. triceps brachii and M. teres major. A similar hand skeleton structure (in which the second, third and fourth metacarpals and phalanges act as a digging apparatus) was observed in both species. Our observations confirm that both these species have muscular-skeletal adaptations supporting fossorial locomotion. As each species belongs to a monophyletic subfamily within the Tenrecidae isolated in Madagascar, such semifossorial adaptations are assumed to have evolved convergently.
Endo
H
H
Section of Morphology, Primate Research Institute, Kyoto University, Inuyama, Aichi, Japan. endo@pri.kyoto-u.ac.jp
Oishi
M
M
Yonezawa
T
T
Rakotondraparany
F
F
Hasegawa
M
M
D000222:Adaptation, Physiological; D000818:Animals; D005075:Biological Evolution; D007312:Eulipotyphla / Q000033:anatomy & histology* / Q000502:physiology*; D005552:Forelimb / Q000033:anatomy & histology / Q000502:physiology*; D008124:Locomotion / Q000502:physiology; D018485:Muscle Fibers, Skeletal / Q000502:physiology / Q000648:ultrastructure; D018482:Muscle, Skeletal / Q000502:physiology* / Q000648:ultrastructure; D013045:Species Specificity