Рад у часопису

објављена верзија

енглески

Barbara V. Radulović

New Pliensbachian rhynchonellide (Brachiopoda) from Livari, (Rumija Mountain, Montenegro): taxonomy and shell microstructure implications

Historical Biology

2022

An interesting case of close external similarity (homoeomorphy) is revealed by the study of an Early Jurassic rhynchonellide brachiopod from Livari, Rumija Mountain, southern Montenegro. Shell microstructure was used as the primary diagnostic tool, applied before serial sectioning to study internal characters. Sepkoskirhynchia sphaerica gen. et sp. nov. is erected based on the presence of coarse fibrous shell microstructure and subfalciform crura. Because of these primary diagnostic characters, the new genus is placed in the rhynchonellide family Basiliolidae. The shell microstructure of the new taxon is characterized by a differentiated secondary layer of coarse fibrous type. The fibres are rhombic or subquadrate in cross-section, in the external sublayer they are 55–60 μm wide and 40–50 μm thick, internally other sublayers are thinner with fibres 35–40 μm wide and 20–25 μm thick. The main character that distinguishes the new genus is that the secondary layer is differentiated into several sublayers, while in externally homoeomorphic Soaresirhynchia it is built of a single layer. The new taxon was found in the brachiopod and crinoidal limestones from the periplatform facies of the Dinaric Carbonate Platform.

34

12

0891-2963 (print); 1029-2381 (web)

Brachiopods; Jurassic, Sepkoskirhynchia, Soaresirhynchia, shell microstructure, Dinaric Carbonate Platform

M20

М21

Затворени приступ

All rights reserved

.pdf