Exceptional preservation of nerve and muscle tissues in Late Devonian placoderm fish and their evolutionary implications
http://rsbl.royalsocietypublishing.org/content/3/2/197.full.pdf
(Comment) Placoderm muscles and chordate interrelationships
http://www.ncbi.nlm.nih.gov/pmc....358.pdf Number and arrangement of extraocular muscles in primitive gnathostomes: evidence from extinct placoderm fishes
http://www.ncbi.nlm.nih.gov/pmc....545.pdf
Fusion, gene misexpression and homeotic transformations in vertebral development of the gnathostome stem group
(Placodermi) http://www.biosci.ohiou.edu/faculty....010.pdf