﻿Stephanoceras 



Lytoceras 



/Egoceras 



Mecho- 

 chirus 



Eryon 



Sponges 



(Cylindro- 



phyma) 



Crab 



(Palaeina- 

 chus) 



Aspidoceras 



Cardioceras 



JURASSIC PERIOD 



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