Concept
Version 8
Created by Boundless
The Evolution of Craniata and Vertebrata
Vertebrates
Vertebrata are characterized by the presence of a backbone, such as the one that runs through the middle of this fish. All vertebrates are in the Craniata clade and have a cranium.
Source
Boundless vets and curates high-quality, openly licensed content from around the Internet. This particular resource used the following sources:
"OpenStax College, Chordates. October 17, 2013."
http://cnx.org/content/m44685/latest/Figure_29_01_06.jpg
OpenStax CNX
CC BY 3.0.