Alexander O. Averianov* & Pavel P. Skutschas**
*Zoological Institute, Russian Academy of Sciences, Universitetskaya nab. 1, St. Petersburg 199034, Russia
**Faculty of Biology, St. Petersburg State University, Universitetskaya nab. 7/9, St. Petersburg 199034, Russia
The phylogenetic analysis of 25 taxa of basal tribosphenic mammals, based on 34 characters distribution, is performed. It reveals two main monophyletic groups: Eutheria (including Pappotherium) and Metatheria (including Deltatheridium, Kokopelia, and Asiatherium) and paraphyletic “tribotheres” with partially hierarchic pattern (Picopsidae, Aegialodontidae).
Eugenia A. Dorofeyeva
Zoological Institute, Russian Academy of Sciences, Universitetskaya nab., 1, St. Petersburg, 199034, Russia
The classification system of the suborder Salmonoidei is constructed on the basis of morphological, embryological, ontogenetical and paleontological data, considering specific characteristic of structure of the species and polyploid origin of the group. In the fauna of Eurasia, all of the genera of the family Salmonidae are represented: Brachymystax, Hucho, Parahucho, Salvelinus, Salvethymus (subfam. Brachymystacinae) and Salmo, Salmothymus, Acantholingua, Parasalmo, Oncorhynchus (subfam. Salmoninae). Phylogenetic links of chars, lenoks are confirmed by resemblance in ontogenetic development of the vomer, which is principally different from the formation of this bone in salmons and trouts. Osteological features give reasons to regard the Pacific trout as a distinct taxon (genus Parasalmo).
Mark I. Falkovitsh
Zoological Institute, Russian Academy of Sciences, Universitetskaya nab., 1, St. Petersburg, 199034, Russia
The following groups by a character of nutrition are considered. 1) Gall-makers which are characterized by the most narrow trophic relations. 2) Species with inter-tissue nutrition as well as rather specialized in accordance with plant taxa. 3) Suctorial insects with the different range of host-plant relationships. 4) Gnawing insects, among them narrow oligophages and insects with wider host-plant relationships (Coleoptera). The most suitable for our purpose are the groups which are rich in the specialized species and genera, they give a possibility to come to taxonomic conclusions at the different levels of botanical system. Microlepidoptera (firstly casebearers), gall-midges and flea-louseare are of such type.
Trophic relations of insects represent a totality of characters, which include many plant peculiarities – biochemistry, ecology, biocoenology, etc. It allows using indices of host-plant relationships to make a complex evaluation of botanical taxa.
Data obtained are used for revealing natural plant groups, establishing a rank and contents of taxa, for more precise definition their relationships, etc. Methods of solution of mentioned problems are given with concrete examples. In accordance to a principle of reverse relation the data on systematics and phylogeny of the Chenopodiaceae give a possibility to elaborate analogous problems also when studying insects. The most complete scheme of co-evolution of plants and insects may be given by synchronous, parallel investigation of the both groups of these organisms.
Roman V. Smirnov
Zoological Institute, Russian Academy of Sciences, Universitetskaya nab., St. Petersburg, 199034, Russia
Ivanov’s-Beklemishev’s concept of phylogenetic relationships of the frenulate and monilifer taxa is a subject to criticism. A new scheme of evolutionary changes in the key organ systems is suggested. The way of origin of the skin organs (glands and papillae) metamerism is reviewed.