Paleoecology of microencrusters and encrusting “coralline” sponges in Cipit boulders from the Cassian formation (upper Ladinian-lower Carnian, Dolomites, Northern Italy)

Abstract

New occurrences of the encrusting “coralline” sponges Murania kazmierczaki Reitner, Murania megaspiculata Reitner, and Ceratoporella breviacanthostyla Reitner, often associated with microencrusters, are recorded from the Alpe di Specie (Seelandalpe) and Misurina near Cortina d′Ampezzo in the Dolomites in South Tyrol, Northern Italy. Some specimens with excellently preserved spicule pseudomorphs account for this finding. M. kazmierczaki and Ceratoporella breviacanthostyla normally appear to some extent associated with microencrusters and have strong framework-binding properties, while M. megaspiculata is seldom associated with any of them. The microencrusters involved in these associations include crusts similar to Pseudorothpletzella Schlagintweit and Gawlick, crusts similar to Wetheredella Wood, thalamid sponges, “Tubiphytes” Maslov, single- and multi-chambered foraminifera, and Koskinobullina cf. K. socialis Cherchi and Schroeder. While the associations between M. kazmierczaki and Ceratoporella breviacanthostyla are certainly similar, some microencrusters related to one of them are not related to the other.