Содержание: Том 1 (2) 2002 (отпечатан 7 March 2003)
Maschenko E.N., Lopatin A.V., Voronkevich A.V.
Sibirotherium rossicus gen. et sp. nov. from the Early Cretaceous Ilek Svita in West Siberia (Shestakovo locality) is described based on lower jaw fragments. The lower molars exhibit the typical docodont pattern with the main cusp a connected by transverse crests to the lingual cusps c and g. By absence of crests b–g and c–d, and presence of crests b–e and e–g, as well as by the development of an enlarged anterior basin, Sibirotherium gen. nov. is similar to Tegotherium from the Late Jurassic of Mongolia. These two genera are united in the endemic Asian family Tegotheriidae. The new genus is plesiomorphic in retaining well developed crest d–f, and it is more derived than Tegotherium in partial reduction of the crest e–g. The morphological diversity of the tegotheriids suggests a significant differentiation of the Late Jurassic — Early Cretaceous docodonts in Asia.
The detailed description of the latest Miocene (MN 13) maxillary fragment with P4-M2 of Indarctos bear from Ananiev in the southern Ukraine is given. The specimen is assigned to the subspecies I. punjabiensis atticus (Weithofer, 1888), comb. nov. A pronounced similarity revealed in tooth proportions and size between I. p. atticus and I. oregonensis from the North American late Miocene suggests I. oregonensis to be only a subspecies: I. punjabiensis oregonensis Merriam, Stock et Moody, 1916, comb. nov. The Indarctos records from the territory of the former USSR are reviewed.
Gambaryan P.P., Gasc J.-P., Renous S.
The burrowing process of the common mole Talpa europaea Linnaeus, 1758 was investigated by the cinefluorography. During burrowing the humerus is abduced only on 25–30°. This abduction is realized by the rotation of the scapula around its longitudinal axis and by the translation of the clavicle in the sternoclavicular and claviculohumeral joints. The abduction of the shoulder joint is limited to 10–15° by nearly complete coincidence of the articular surfaces of the scapular glenoid fossa and the humeral head. The shoulder joint extension diminishes the abductors momentum on 30–70% and in this case they cannot develop the force determined in the experiments. M. flexor digitorum profundus is transformed in the ligament which origins on the median epicondyle of humerus and inserts on all the five ungual phalanges. This is an unique mechanism for the neutralization pronation momentum of the humerus abductors. The increasing of the pressure of the hands on the soil augments the tension of the m. flexor digitorum profundus what hinders the pronation of the humerus. The increasing of the rotation of the antebrachium is necessary to maintain the hand in a parasagittal plane. An accretion of the humeral median epicondyle promotes decreasing of the humerus rotation. Humerus rotates during terrestrial locomotion in all tetrapods with sprawling limb position (humerus pronates in the propulsive phase and supinates in the swing phase). The recent Monotremata and probably primitive mammals use the humerus pronation for the lengthening of the stride. Mm. supraspinatus and infraspinatus prevent the humerus retraction. The widening of the humerus in these mammals is an adaptation to its rotation by the limited abduction and retraction. On the contrary, the widening of humerus in moles is an adaptation to its abduction by the limited rotation. Thus the convergent widening of the humerus in these animals is caused by the diametrically opposite functions.
Morphology of the thoracic and lumbar vertebrae is described. During digging and moving through the tunnel mole can turn anterior part of its body relative to the posterior part up to 90°. An original method to estimate the rotation angle between two vertebrae was devised. It was revealed that the main twisting range occur in the thorax region, and in the lumbar region it comes to naught. The absence or weak development of the spinous process in the anterior thoracic vertebrae indicate weakness of the musculature responsible for the head raising. Based on this observation it is asserted that mole can not use its head for throwing out the soil.
Golenishchev F.N., Malikov V.G., Nazari F., Vaziri A.Sh., Sablina O.V., Polyakov A.V.
According to data on comparative cytogenetics, morphology and hybridization a new species Microtus (Sumeriomys) qazvinensis Golenishchev sp. nov. from Bu’in-Zahra (Qazvin Province, Northern Iran) is described.
Abramson N.I., Tikhonova E.P.
The degree of craniometric differences between the taxa, chromosome races and phylogeographic groups of the genus Dicrostonyx in the Palaearctic were accessed using discriminant function analysis. Contrary to results obtained by the previous authors it was shown that recognized taxa differ significantly in the structure of the skull and mandible. Individual characters and their combinations most suitable for the discrimination of species and subspecies have been revealed. Analysis of correlation between the chromosomal, molecular and morphological divergence in the collared lemming from the Palaearctic part of the range showed that there is consistency between morphological and molecular (mtDNA diversity) data and discrepancy between morphological and chromosomal data. Known models of chromosome speciation and phylogeographic hypotheses are discussed in the light of the data obtained.
Baryshnikov G.F., Puzachenko A.Yu., Abramov A.V.
Variation of cheek teeth in 661 specimens of Eurasian badgers was studied. Geographic distribution of tooth size and morphotypical characters was analyzed. Presence of two groups of badgers (“western” and “eastern”) regarded as allopatric species Meles meles and M. anakuma is confirmed. The small badger from south-western Norway is placed in a new subspecies M. meles milleri ssp. nov. Mosaic pattern of distribution of dental characters and different directions of specialization of cheek teeth in Meles meles and M. anakuma are established. It is assumed on the basis of paleontological material that both species originated from the Late Pliocene M. thorali, their divergence began in the early Pleistocene, and separation on species level occurred in the Middle Pleistocene.