Fig. 2From: Monoplacophorans and the Origin and Relationships of MollusksStratigraphic occurrence and generic diversity of Monoplacophora with paired muscle scars (Tryblidacea). Although living species have been allocated to numerous genera, they are represented here by a single lineage. Data from Sepkoski (2002) and The Paleobiology database (http://paleodb.org/)Back to article page