Solutan echinoderms from the Lower Ordovician of the Montagne Noire (France): new data and palaeobiogeographic implications

Abstract

Solutans are relatively common members of echinoderm assemblages in the Saint-Chinian Formation (upper Tremadocian) of the Montagne Noire (France). The revision of all available material confirms that most specimens can be assigned to Minervaecystis vidali, which is here reconstructed for the first time. The occurrence of Plasiacystis mobilis is evidenced based on a single, well-preserved dististele. The interpretation of the small-sized individual as a putative dendrocystitid is rejected: it corresponds to a juvenile specimen of M. vidali. Early Ordovician solutans from the Montagne Noire partly fill the gap between Laurentian mid–late Cambrian syringocrinids and Avalonian-Gondwanan Early–Middle Ordovician taxa.

Keywords

• echinodermata
• montagne noire
• ordovician
• solutan
• tremadocian