Image: Spindle diagram

Description: Evolution of Vertebrate from the Cambrium to the present at a class level as a traditional spindle diagram. The width of the spindle represents the number of families as a rough estimate of diversity. The diagram is based on Benton, M. J. (1998) The quality of the fossil record of vertebrates. P. 269–303, in Donovan, S. K. and Paul, C. R. C. (eds), The adequacy of the fossil record, Fig. 2. Wiley, New York, 312 p. The figures representing classes are (from left): Agnatha, Chondrichthyes, Osteichthyes, Amphibia, Reptilia, Aves and Mammalia. The two extinct classes are Placodermi and Acanthodii. All classes interpreted traditionally. Bentons notes to his own tree: Number of families is an imperfect measure of diversity. Reptilia in particular should probably have been shown as far more diverse in the Mesozoic.
Title: Spindle diagram
Credit: Own work
Author: Petter Bøckman
Usage Terms: Public domain
License: Public domain
Attribution Required?: No