Lower Kimmeridgian echinoids of Poland

• Autorzy: Radwańska U.
• Języki publikacji: EN

Abstrakty

EN

A rich assemblage of echinoids, primarily regular ones, is reported from the Lower Kimmeridgian part of an over 1km thick Upper Jurassic carbonate sequence, developed over cratonic (epicontinental) areas of Poland (Holy Cross Mountains in Central Poland, and Western Pomerania in NW Poland). The echinoids, either underestimated or even overlooked in the former literature, appear to be significant components of ubiquitos organic assemblages contained in various deposits of the bahamite type of facies. The most diversified taxonomically are the echinoids from Ma?ogoszcz in the Holy Cross Mountains (22 species, of which 4 dominate: Rhabdocidaris orbignyana, Hemicidaris intermedia, Gymnocidaris agassizi, Holectypus corallinus). The richest numerrically is the collection from Czarnog?owy in Western Pomerania (13 species, of which only 2 dominate: Hemicidaris hoffmanni and Nucleolites letteroni). The systematically accounted forms, totalling over 2000 specimens, represent 31 species of 20 regular genera, and 10 species of 5 irregular genera. Of these, four species are new to science, viz. Pseudosalenia malogostiana sp.n., Pseudocidaris sanctacrucensis sp.n., Trochotiara kongieli sp. n., and T. suleiovense sp. n. The well preserved specimens, although usually devoid of spines and apical plates, display the SEM-recognizable features of the tests (i.a. pore-pairs morphology, tubercle arrangement) substantial for a functional analysis of 14 more commonly occurring species. This analysis stimulated a paleobiologic interpretation focused on the behavioral and environmental (very shallow up to subtidal) conditions under which the studied echinoids lived and were buried i.a. by such catastrophic events as storm-induced and mass-movent deposition. A separate, short section of the paper concerns the grazing traces of regular echinoids [classified in ichnology as Gnathichnus pentax BROMLEY, 1975], caused by browsing the epibionts, and preserved in the studied sequence on various organic (shelly) substrates, the other echinoid tests including.

Słowa kluczowe

EN

Echinoidea; paleoecology; Poland; taxonomy; Upper Jurassic

• Wydawca: Faculty of Geology of the University of Warsaw ; Komitet Nauk Geologicznych PAN
• Czasopismo: Acta Geologica Polonica
• Rocznik: 1999
• Tom: Vol. 49, no. 4
• Strony: 287--364
• Opis fizyczny: Bibliogr. 130 poz., tab., rys.

Twórcy

autor

Radwańska U.

• Institute of Geology, University of Warsaw, Al. Żwirki i Wigury 93, PL-02-089 Warszawa, Poland