Phacops or proteid help

[JohnB]

Hello everyone

I have two trilobites which I'm having problems with. One was sold to me by a French dealer as a phacops from Alnif, Morocco and the other I bought from eBay with several other fossils and was told it was a proteid. I'm aware of the difference in the eyes but these trilos eye lenses have gone leaving just smooth round eyes. Any other ways of distinguishing them?

Thanks

John

[Lugo]

Hi John

maybe this link

http://www.trilobites.info/trilokey.htm

can help you to understand the differences between the various Orders and Families of trilobites, included the Phacopida and Proetida.

best regards

Lugo

[Frederik]

Hi John,

Can you post a picture? Depending on the genera involved, it might be quite easy to give you some good rules of thumb to distinguish them. Usually the eyes are a giveaway, but the most common proetid on the Moroccan market (Gerastos) has 10 segments, while the phacopinae have 11.

[JohnB]

Thanks Lugo. I did find the site and had a brief look yesterday. I'll look again. It's s great resource.

John

[JohnB]

Hi Frederik

Are segments the horizontal parts in the thorax?

John