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Category:Polydactyly in early tetrapods

Limb evolution: A. Eusthenopteron, B. Gogonasus, C. Panderichthys, D. Tiktaalik, E. Acanthostega, F. Ichthyostega ( hindleg ), and G. Tulerpeton.

Early groups like Acanthostega had eight digits, while the more derived Ichthyostega had seven digits, the yet-more derived Tulerpeton had six toes.Crassigyrinus from the fossil-poor Romer's gap in early Carboniferous is usually thought to have had five digits to each foot. The amphibian Anthracosaurs had a five-toe pattern still found in their Amniote descendants, while further reduction had taken place on other Labyrinthodont lines, leaving the forefoot with four toes and the hind foot with five, a pattern still found in modern amphibians. [1]


  1. Benton, M. (2005): Vertebrate Palaeontology 3rd edition. Blackwell Publishing

Media in category "Polydactyly in early tetrapods"

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