Fosilne cevke iz brezstrope jame - verjetno najstarejši ostanki jamskega cevkarja Marifugia (Annelida: Polychaeta)

Abstract

Članek je poročilo o odkritju cevk jamskega cevkarja v brezstropi jami v kamnolomu nad Črnim kalom. Opisano je nahajališče ter oblika fosilnih cevk. Živali so živele pritrjene na fasetirano steno rova. Rov je nato zapolnila ilovica, nato pa še več metrov debela siga. Strop rova in njegov gornji del je kraška denudacija že odstranila, tako da sega siga že na površje. Na skalni steni so se ohranili prirasli deli cevk različno velikih živali, deli cevk, ki so rasli pravokotno na steno pa so se odlomili, vendar so se ohranili v sedimentu. Cevke so po dimenzijah in obliki podobne cevkam recentnega jamskega cevkarja Marifugia cavatica Absolon in Hrabe. Po legi ohranjenih cevk ter dataciji bližnjih sedimentov s paleomagnetno metodo sodimo, da so ostanki cevkarjev najmanj pliocenske starosti.

The paper is a report on the discovery of tubes of a fossilized cave serpulid in a roofless cave in the quarry above Črni Kal village. The site and shape of the fossilized tubes are described. The animals lived attached to the scallops in the wall of the passage. The passage was later filled with clay deposits, followed by a layer of flowstone several metres thick. The roof of the passage has been removed by karst denudation and flowstone now reaches to the surface. Fragments of tubes of animals of various sizes have been preserved, attached to the rock wall; those tubes which grew at a right angle to the wall have broken off but have been preserved in the sediment. In terms of their dimension and shape the tubes remind one of the tubes of the more recent cave serpulid Marifugia cavatica Absolon and Hrabe. The positions of the preserved tubes and the dating of the nearby sediments by palaeomagnetic method indicate that the remains of the serpulids are from the Pliocene epoch or older.