Szczegóły

Tytuł artykułu

Badenian (Middle Miocene) echinoids and starfish from western Ukraine, and their biogeographic and stratigraphic significance

Tytuł czasopisma

Acta Geologica Polonica

Rocznik

2014

Wolumin

vol. 64

Numer

No 2

Autorzy publikacji

Wydział PAN

Nauki o Ziemi

Abstrakt

Abstract Echinoderms from the Badenian (Middle Miocene) of the Fore-Carpathian Basin of western Ukraine are facies restricted. The Mykolaiv Beds, stratigraphically older, yielded the starfish Astropecten forbesi (complete skeletons), two genera of sand dollars (Parascutella, Parmulechinus), and numerous other echinoids of the genera Psammechinus , Echinocyamus, Spatangus, Hemipatagus, Echinocardium, Clypeaster, Echinolampas, and Conolampas. The stratigraphically younger, calcareous Ternopil Beds yielded Eucidaris (complete coronae, isolated spines), Arbacina , Brissus, and Rhabdobrissus. Sixteen species of echinoids are distinguished and/or commented. A new brissid, Rhabdobrissus tarnopolensis sp. nov., is established. A mass occurrence of some species (Psammechinus dubius and Hemipatagus ocellatus) contrasts with that of mass aggregations (sand dollars and Echinocardium leopolitanum) by dynamic events in selected layers of proximal tempestites. Of special note is the occurrence of very small specimens, interpreted as juveniles (‘babies’) having been swept out of their restricted biotopes (‘nurseries’). Some species hitherto regarded as of Early Miocene age, and the problem of their persistence beyond the Fore-Carpathian Basin and/or migration into that basin during the Middle Miocene transgression are discussed.

Wydawca

Komitet Nauk Geologicznych PAN ; Wydział Geologii UW

Data

2014

Identyfikator

ISSN 0001-5709

DOI

10.2478/agp-2014-0012

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