NEW DATA ON THE ORDOVICIAN TRILOBITESOF THE GENUS ILLAENUS DALMAN, 1827 OF EAST BALTOSCANDIA

Authors

  • A.V. Krylov Joint-Stock Company “Polargeo”, Vasiljevski Island, 24th Line, 3-7, Building 20-Б, 199106 St. Petersburg, Russia Автор

Keywords:

trilobites; Illaenus; new species; new subgenera; phylogeny; Ordovician; Еast Baltoscandia; Leningrad region; Novgorod region; Russia

Abstract

Four new subgenera of the genus Illaenus Dalman, 1827: Pseudoillaenus subgen. nov., Trigonillaenus subgen.
nov. Baltillaenus subgen. nov. and Rutheniaeillaenus subgen. nov. are described in the present paper as a result of study
of illaenid trilobites of East Baltoscandia. Three new species: Illaenus (Trigonillaenus) kotlukovae sp. nov., I. (T.)
volkhovensis sp. nov., Illaenus (Rutheniaeillaenus) dubari sp. nov. from the Darriwilian and Katian of Saint-Petersburg
Region and Estonia are described. The article presents diagnosis for three species and subspecies: Illaenus (Illaenus)
chiron stacyi Holm, 1886, I. (I.) planifrons Jaanusson, 1957, Illaenus (Baltillaenus) glabrisculus Jaanusson, 1957, which
includes new morphological data reported here for the first time, as well as defines more exactly diagnosis of two rare
species: Illaenus (Trigonillaenus) schmidti Nieszkowskii, 1857, Illaenus (Illaenus) intermedius Holm, 1886, described
from the Ordovician strata of the Saint-Petersburg and Novgоrod Regions. The neotype of (Trigonillaenus) schmidti
Nieszkowskii, 1857, has been found. A new phylogenetic scheme for East Baltoscandian representatives of the genus
Illaenus (Dalman, 1827) is submitted.

Fig. 65. Tab. 4. Ref.: 20 titles.

Published

2017-09-01

Issue

Section

БИОЛОГИЧЕСКИЕ НАУКИ Общая биология