Myogale digastricus

WHIDDEN, HOWARD P., 2000, Comparative Myology of Moles and the Phylogeny of the Talpidae (Mammalia, Lipotyphla), American Museum Novitates 3294, pp. 1-53 : 7

M. digastricus , venter anterior ( fig. 6 )

The posterior portion of the digastric is discussed with the muscles of the Facial Field.

ORIGIN: A lateral portion from a chevronshaped tendinous inscription with the posterior belly of the digastric, and a medial portion from a tough, concave fascial sheet. This fascial sheet extends posterolaterally from the midline to join the tendinous inscription between the anterior and posterior digastric bellies.

INSERTION: The lateral portion onto the ventral surface of the mandible via a stout digastric tendon, the medial portion onto the ventral surface of the mandible and the digastric tendon.

REMARKS: This muscle has the same general form in Condylura , Neurotrichus , Parascalops , Scalopus , Scapanus , Scaptonyx , Talpa , and Urotrichus . Uropsilus has no medial portion to the anterior belly. Desmana has a lateral portion similar to the other taxa, but the medial portion becomes split, with a superficial layer originating from the tendon of the opposite side, and a deep layer originating from the median raphe of M. mylohyoideus profundus; both layers insert on the digastric tendon near its attachment to the mandible. I did not discern the azygous component that Dobson (1882–1890) described for Desmana . Gaughran (1954) did not identify a tendinous inscription in this muscle in Scalopus , and he identified the lateral portion of the venter anterior as part of the venter posterior. Fiedler’s (1953) interpretation of this muscle in Talpa is similar to mine.

Figures

Fig. 6. Ventral view of neck muscles of Parascalops; superficial muscles on bottom, deeper muscles on top.