- spinal anatomy of amniotes
- ammonite aptychi(transformation of jaw to operculum)
- correlation between large carnivores, mammals and dinosaurs
- productid brachiopod Waagenoconcha abichi("snow-shoe" structure)
The "snow-shoe" structure prevents adult Waagenoconcha abichi from sinking into the soft mud on which it lives. Juveniles have "hooks" for hanging onto plants, until they develop "snow-shoes".