Anatomy and systematics of the Early Jurrasic neoselachian shark Synechodus smithwoodwardi (FRAAS, 1896) from southern Germany

Synechodus smithwoodwardi, a member of Early Jurassic synechodontiform sharks, is redescribed in detail from the unique adult male specimen from the Toarcian of Holzmaden. It consists of an articulated portion of the vertebral column, two dorsal fin spines, the parts of the pectoral and pelvic girdles, the clasper organs, and a shagreen of placoid scales. The densely calcified cyclospondylous vertebrae, the morphology of the fin spines, and presence of non-growing placoidscales support its assignment to neoselachian sharks. The clasper organs are well-preserved and allow a detailed account of copulation organs in Early Jurassic neoselachians for the first time. They have associated cartilages and an armament of two large spines on the spur cartilages. The character combination of Early Jurassic synechodontiforms indicate that they form a monophyletic group that differs from all others.