Skip to main content
Fig. 12 | Zoological Letters

Fig. 12

From: Comparative morphology and development of extra-ocular muscles in the lamprey and gnathostomes reveal the ancestral state and developmental patterns of the vertebrate head

Fig. 12

Hypothetical scenario for the evolution of the EOMs. In the common ancestor of the vertebrates had unsegmented head mesoderm but there were three mesodermal portions with distinct genetic patterning and motor nerve innervation. These had lamprey-type EOMs, which was conserved in Osteostracans and Placoderms (in hagfishes, EOMs are completely degenerated). In the common ancestor of the crown gnathostomes, the disposition of the EOMs changed to the extant-gnathostome-type

Back to article page

Zoological Letters

ISSN: 2056-306X

Contact us