Ptyctodontida

#	Item
1	The first vertebrate sexual organs evolved as an extra pair of legs Add to Reading List Source URL: phys.org Language: English - Date: 2014-12-10 09:11:21 Placodermi Ptyctodontida Fish anatomy Shark Incisoscutum Ctenurella Clasper Gnathostomata Tetrapod Fish Placoderms Ichthyology
2	Devonian arthrodire embryos and the origin of internal fertilisation in vertebrates Add to Reading List Source URL: www.aussmc.org Language: English - Date: 2010-05-11 04:01:24 Incisoscutum Arthrodira Ptyctodontida Shark Ctenurella John A. Long Placoderms Fish Placodermi