Related Links:
Ventral Morphology
Major Features

Special Terms

Hypostome Types
Internal Anatomy
Trilobite Eyes
Facial Sutures
Glossary of terms
I think you should visit the PROETIDA FACT SHEET...

Trilobite Dorsal Morphology
last revised 23 February 2009 by S. M. Gon III

english morphology chart 2006
This drawing ©2007 by S. M. Gon III
Many thanks to Denis Audo and Jim Cook! Many thanks to Manuel Francisco Valério Romão and  Armando Marques-Guedes fg fs
Clicez ici pour le diagramme en français Clique aqui para o diagrama em português Für deutsche version bitte hier klicken Tecleo aquí para el diagrama en español

The image above provides most of the dorsal morphological terms used to define trilobite species, genera, families, and orders. Ventral (underside) morphology can also be important. For example, there are hypostomal attachment terms describing the way the hypostome (a hard mouthpart on the underside of a trilobite) attaches to the rest of the cephalon. There are also broader categories (Major Trilobite Features), that refer to major body divisions such as cephalon, pygidium, cranidium, axis, etc. There are some terms that relate to the relative sizes of the cephalon and pygidium. Facial sutures (lines along which the exoskeleton split to allow molting) are also important in classifying trilobites. There was also significant variation of trilobite eyes. We don't know very much about a trilobite's internal anatomy, with some exceptions! Finally there are some special morphological terms that apply only to certain groups of trilobites. If you want more detailed definitions of the terms in the image above, I have provided a general alphabetical glossary of terms.

stroll with me among the topics below...
Walking Trilobite animation ©2000 by S. M. Gon III