Содержание: Том 4 (1) 2005 (отпечатан 5 December 2005)
Averianov A.O., Skutschas P.P., Lopatin A.V., Leshchinskiy S.V., Rezvyi A.S., Fayngertz A.V.
A small sample of mammalian isolated teeth and edentulous dentary fragments from the Early Cretaceous locality Bol’shoi Kemchug 3 in Krasnoyarsk Territory, West Siberia, Russia, represents five taxa: amphilestid Kemchugia magna gen. & sp. nov., Amphilestidae indet., gobiconodontids Gobiconodon sp. A and B, and Mammalia indet. The large sized Kemchugia magna gen. & sp. nov. is based on two isolated molariforms. Amphilestidae indet. is represented by single molariform and two edentulous dentary fragments. Gobiconodon sp. A is similar in size to G. hoburensis from the Early Cretaceous of Mongolia. Gobiconodon sp. B is some 20% larger than G. borissiaki from the Early Cretaceous of Mongolia. A minute edentulous dentary with alveoli for two posterior molariforms is referred to Mammalia indet. Dental lamina pits on the lingual side of gobiconodontid jaws, interpreted as openings for the epidermal filaments connecting the dental lamina with the growing enamel cup of a developing tooth germ, are reported here for the first time and confirm replacement of molariform teeth in Gobiconodontidae.
Gambaryan P.P., Zherebtsova O.V., Platonov V.V.
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 second–sixths (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 four–six times stronger than such in Rattus; the extensors of the occipital joint are 20 times stronger than those in Talpa.
Thirty-one bat species have been registered in the course of two expeditions to Cambodia in January–February 2000 and July–September 2002. Eight of them, namely Macroglossus sobrinus, Taphozous theobaldi, Hipposideros cineraceus, H. galeritus, Rhinolophus pusillus, Miniopterus schreibersii, Miniopterus sp., and Harpiocephalus harpia are reported from Cambodia for the first time. Occurrence of Rousettus leschenaulti and Pteropus hypomelanus is confirmed, while that of Saccolaimus saccolaimus, on contrary, rejected. Specific distinctiveness of Harpiocephalus mordax has been rejected in the view of the latest findings, including the molecular data. It should be regarded as a synonym of H. harpia. One species, Miniopterus sp., is not identified at this stage, and is likely to represent a new species. In general, Cambodian bat fauna could be characterised as typical Indomalayan, with almost 70% of its registered species not occurring outside the region. It is lacking any species common in the neighbouring zoogeographic regions, with only one, Miniopterus schreibersii, occurring throughout the Old World, Australia, and Oceania. An annotated species list, with notes on taxonomy, distribution and occasionally ecology is presented. Selected measurements have been given as well. Updated checklist with 48 registered bat species is proposed.
Abramson N.I., Tikhonova E.P.
Uni- and multivariate analyses of skull 27 measurements of 353 M. oeconomus specimens from 46 sites, covering most part of the range in Eurasia and 11 specimens from Alaska revealed the existence of three morphologically distinct groups. Therewith, two of them, uniting all samples from Palaearctic formed two clusters joined together, and each represented a set of samples that in its turn could be defined as so-called western and eastern groups. An approximate border between these groups can be allocated in the region of the Lena River. Morphological data are in good agreement here with molecular data in uniting all root voles from the European North in one group. Voles from Urals, Western Siberia and Krasnoyarsk Territory morphologically are very close to this north-European group, though molecular data place them in another clade. Distinction on western and eastern groups disagrees with molecular data. We relate this discrepancy only with poor sampling in molecular studies to the current moment. The third group is formed by samples from Chukotka, Alaska and Kamchatka and constitutes the so-called Beringian clade, what is in a good agreement with molecular data. However poorly studied with molecular methods the voles from Kamchatka differ seriously from other representatives of the group and no doubt that taxonomically they represent an independent taxon of subspecies rank.
Dokuchaev N.E., Dorogoy I.V.
New records of Microtus hyperboreus in Chukotka extend the range of the species much further to the East and Northeast than was known previously.
Maschenko E.N., Tikhonov A.N., MacPhee R.D.E.
For the first time, the skull of a mammoth calf of approximately two years is described. This skull comes from Bolshoi Lyakhovskii Island in the New Siberian group, which is the island closest to the mainland. The radiocarbon date of this find, 24,700±170 yrbp (not corrected 13C), places the specimen just before the last glacial maximum in Siberia and suggests the absence of oceanic glaciation in this area. The finite date record for mammoths in the New Siberian Islands is compared to that for the immediately adjacent mainland (lower Lena River/Lena Delta region).