 "Cartorhynchus" can also be distinguished by its parapophyses, vertebral processes that articulated with the ribs; their front margins were confluent with those of the vertebrae.Both "Cartorhynchus" and "Sclerocormus" had heavily-built ribcages, which were deepest near the shoulder, with broad, flattened, and thick-walled ribs, as is commonly seen in early members of secondarily-aquatic reptile lineages.The Ichthyopterygia lost these flattened ribs with the exception of "Mollesaurus".