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Article history:
Manuscript received August 03, 2017
Revised manuscript accepted October 04, 2017
Available online October 31, 2017
Keywords: Selliporella genus, Dasycladales, taxonomy, biostratigraphy, Dinarides, Croatia
Abstract
An emended diagnosis of the genus Selliporella and its type-species, S. donzellii SARTONI & CRESCENTI is proposed, based on the proven existence of non-ramified laterals in the mature (basal) part of the thallus and their ramification in its higher (juvenile) parts. Given the differences in the morphological characteristics of laterals in the upper parts of the thallus, the type-species has been split into two varieties: S. donzellii var. donzellii SARTONI & CRESCENTI and S. donzellii var. galaeformis n. comb. Selliporella cornutuformis n. sp. is proposed, characterized by a distinctly articulated (segmented) and spiky thallus, with each primary lateral bearing a bundle of several trichophorous secondaries. The generic attribution of species originally described as Diplopora johnsoni PRATURLON and Triploporella neocomiensis RADOIČIĆ has been reviewed, resulting in their being unified as the same species, which, according to its newly observed morphological characters, has been ascribed to the genus Pseudoclypeina. As Diplopora johnsoni has been validly described, Triploporella neocomiensis becomes, taxonomically, the younger synonym of Pseudoclypeina johnsoni (PRATURLON) n. comb.
1. INTRODUCTION
The genus Selliporella SARTONI & CRESCENTI, 1962 was established on the basis of inadequately illustrated, fragmented sections of individual whorls. Thus, the lack of more complete parts of thallus resulted, then, in an incomplete diagnosis as follows: „Essentially cylindrical thallus, with generally detached and separately fossilized whorls. Fertile whorls in a basket shape, each one formed by laterals of two or more superposed rows. Phloiophorous laterals are welded together. Laterals of the same row communicate with one another; but the laterals of the various rows of the same whorl have rare, sporadic and often absent communication." (SARTONI & CRESCENTI, 1962). Such inadequate and even, to some extent confusing, diagnosis resulted in fragments or sections of different characteristics being ascribed to Selliporella donzellii, and even in the description of a new species, Teutloporella gallaeformis RADOIČIĆ, 1965, which, after the establishment of the new genus Neoteutloporella BASSOULLET et al., 1978, will be ascribed to the latter. In neither species description (Selliporella donzellii and Teutloporella gallaeformis) are the articulation of the thallus and the bipartite laterals explicitly mentioned, though RADOIČIĆ (1965)...