Fossil holothurian ossicles from the lower Toarcian of the Balkan Mts, Bulgaria

Fossil holothurian ossicles from three localities of the lower Toarcian in the Balkan Mts (Bulgaria), assigned to the family Chiridotidae and the parafamilies Theeliidae, Priscopedatidae and Calclamnidae, were studied. Two types of ossicles and four morphogenera were described: 1) wheels, among which Palaeotrochodota (abundant) and Theelia (single specimens); and 2) perforated ossicles, including Priscopedatus and Cucumarites (both in single specimens). These fossils are well known in Europe but have not been recorded in Toarcian rocks from Bulgaria to date. The studied fauna remains of undetermined palaeoenvironmental significance, although the high morphological variability and abundance of Palaeotrochodota seem potentially informative.