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Russian Journal of Theriology

Morphofunctional analysis of the cervical-thoracic region in some burrowing mammals // Russian J. Theriol. Vol.4. No.1: 1341 [in English].

ABSTRACT. The comparative analysis of such high specialized burrowers as Talpa europaea, Spalax microphthalmus, Nannospalax nehringi, Myospalax myospalax and generalized non-burrowing Rattus norvegicus was carried out to reveal their adaptive peculiarities in the skeleton and muscles structure of cervical-thoracic region. In Talpa during the pushing the soil apart with the forelimbs the drawing of head backwards between the hands is observed. It results in arched neck position, atlas being displaced on the ventral parts of the occipital condyles. At the drawing the head forward during the searching of food the role of m. longus colli is most important. For its insertion in Talpa, in contrast to that of other burrowers and Rattus, the specific ventral plates are developed not only on the sixth, but also on the fourth and fifth cervical vertebrae. The particular mobility in thoracic region in Talpa testifies that during the throwing out the soil the forelimbs are used. Spalax, Nannospalax, and Myospalax, on the contrary, throw the soil out with the head. It becomes possible at the significant consolidation of the cervical vertebrae by the sharp decreasing of their mobility up to the partial accretion. However, in comparison to Rattus and Talpa, the higher mobility in the occipital joint is observed. Moreover, the increasing of solidity of the first thorax segment and formation of the specific withers on the secondsixths (seventh) thoracic vertebrae take place. Three main groups of the muscles (extensors of occipital and elbow joints; the muscles lifting the body between the forelimbs) acting at the process of throwing the soil with the head in spalacids and Myospalax are about foursix times stronger than such in Rattus; the extensors of the occipital joint are 20 times stronger than those in Talpa. KEY WORDS: Talpidae, Spalacidae, Myospalacidae, skeleton, musculature, burrowing.