The turtle shell (carapace) burst into the evolutionary record over an unusually brief period, and by a very dramatic route - the external repositioning and fusion of the dorsal ribcage. A new series of 3D animations produced by the Laboratory for Evolutionary Morphogenesis show how this occurred by developmental repatterning, and how it makes the turtle skeleton so distinct among vertebrates. (previous work)
The five brief animations depict the following aspects of this intriguing development in evolutionary morphology:
1. Evolutionary changes leading to
the turtle shell.
2. Developmental patterning of the
modern turtle shell.
3. Generalized developmental patterning
of the amniote trunk, showing theropod
(bird ancestor) as an example
4. Anatomy of the ribcage and scapula
in the chick
5. Anatomy of the turtle carapace (= ribs) encapsulating the scapula
These videos are released for non-commerical use under a Creative Commons attribution license. No permission is necessary for personal or educational re-use of the animations, but all users should acknowledge the RIKEN Center for Developmental Biology as the original source in all uses or derivative works.
