Fig. 16From: A new species of Palaeopython (Serpentes) and other extinct squamates from the Eocene of Dielsdorf (Zurich, Switzerland)Modification of the zygosphene shape throughout ontogeny of “booid” snakes: a the 139th vertebra of a young specimen of a Boa constrictor (SMF-PH 45); b the 139th vertebra of an adult specimen of Boa constrictor (SMF-PH 40). Both specimens in anterior view. Photographs by Krister Smith, courtesy of the Senckenberg Research Institute, Palaeoherpetology collectionBack to article page