[Morphological diversity in the postnatal skull development in representatives of two families of rodents (Spalacidae, Castoridae, Rodentia)].

This is the first study to describe the results of measurement of three information parameters of morphological diversity (entropy, the measure of organization, and the Kullback-Leibler divergence) in the course of postnatal development of the skull in the populations of two rodent species (greater mole rat (Spalax microphthalmus Guld.) and Eurasian beaver (Castor fiber (L.)). The terms "morphosystem" and "morphological space" and its structure are introduced. Within the framework of the developed approach, "morphological diversity" is considered as a variable associated with the morphological space structure. Testing the hypothesis of the dominance of self-organization processes and an increase in the organization of the morphological diversity of the skull in the course ofontogeny showed its inconsistency. The morphosystem of the skull of the studied species undergoes transitions between more organized and less organized states, periodically approaching and departing from the "steady state." Such dynamics characterizes the morphosystem of the skull as a dynamic and nonlinear system.

[Chromosomal polymorphism in mole rat Spalax microphthalmus (Rodentia, Spalacidae) from results of differential staining]. / Khromosomnyi polimorfizm u obyknovennogo slepysha Spalax microphthalmus (Rodentia, Spalacidae) po rezul'tatam differentsial'nogo okrashivaniia.

Differential stained chromosomes of the mole rat Spalax microphthalmus Guld. (Rodentia, Spalacidae) (2n = 60; NF = 110-112) from Streletskaya and Kazatskaya steppes (Kurskaya oblast, Russia) are described. Animals heterozygous for a complex chromosome rearrangement resulting in increased chromosome size and altered location of the centromere were revealed.