Iberian Trilobites Id request

[mediterranic]

This one is from Arouca, Portugal and it seems an Harpidae. Someone knows the correct ID, please?

 

Thanks in advance,

 

Miguel

[Pumpkinhead]

Another option would be Dionide sp, which is an Asaphid trilobite in the superfamily Trinucleoidea. It is known from Portugal.

 

Take this with a grain of salt, someone like @piranha will have a better idea of what that is.

Edited July 30, 2017 by Pumpkinhead
grammar

[Pumpkinhead]

If you search Dionide on the paleobiology database, the locality shown in Portugal is very close to Arouca. The occurrences are said to be from the Valongo formation, if that helps.

 

I've mistaken members of the Trinucleoidea for Harpetid trilobites before. The large genal spines as well as the sometimes brimmed cephalon that can give the appearance of the "Harpetid brim" can be confusing. Some information that may help tell the difference between the two is that trinucleoids typically have a convex, pear shaped glabella. Their cheeks are also prominent and arched, and are separated from the glabella by deep furrows (tri-nucleate). Trinucleoids are also blind, while Harpetid trilobites typically show small eye nodules. Primitive Trinucleoids will also have a ventral median suture present and some species have a preoccipital tubercle present as well. Thoracic segments in members of Trinucleoidea also have adaxial pleurae.

 

Trinucleus shows this tri-nucleate structure.

 

In Harpetid trilobites the glabella is also ususally convex, but instead of being pear shaped it typically tapers forward. 

[mediterranic]

Thanks a lot @Pumpkinhead

 

There is one Moroccan Trinucleoid: