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Cephalic Muscle Evolution in Chordates
Author(s) -
Ziermann Janine,
Diogo Rui
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.345.4
Subject(s) - myology , biology , vertebrate , extant taxon , anatomy , most recent common ancestor , evolutionary biology , tetrapod (structure) , pectoral girdle , sister group , hagfish , zoology , phylogenetic tree , paleontology , clade , biochemistry , gene
The origin and early evolution of the vertebrate head has fascinated scientists for centuries. However, many studies still do not include an extensive analysis of soft tissues, such as muscles. Urochordates are the closest sister‐group of vertebrates and the recent finding that urochordates have a cardiopharyngeal field has a great impact in our understanding of the origin and evolution of vertebrates. We provide and updated overview of the cephalic muscles in cyclostomes and chondrichthyans and present and extensive comparative analyses that infers the plesiomorphic conditions for vertebrates and gnathostomes. Based on this homologies and important evolutionary patterns of the cephalic muscles in vertebrates will be presented. The last common ancestor of extant vertebrates probably had one intermandibularis and other mandibular muscles (labial muscles), some constrictores branchiales and hyoidei, and epibranchial and hypobranchial muscle sheets. The division of the cucullaris into levatores arcuum branchialium and protractor pectoralis is an osteichthyan synapomorphy and reflects an evolutionary trend towards a greater separation between the head and pectoral girdle that culminated in the formation of the tetrapod neck. Those results provide a basis for future evolutionary and developmental studies of vertebrates and their subgroups.