Peculiar Trilobite

[Hollardops Bro]

Hello everyone,

 

Here I have a peculiar trilobite specimen that I discovered cracking shale from the Wheeler Formation. It comes from the House Range in Millard County, Utah, and I know it's mid Cambrian.

 

Thanks!

 

 

[Sagebrush Steve]

Looks like a typical Elrathia kingii molt with something else I can’t identify next to it.

[Kane]

Agreed. Elrathia.

[piranha]

This specimen is a late meraspid stage Elrathia kingii (approximately M9-M10).

A mature holaspid has 13 thoracic segments and 4 axial rings on the pygidium.

 

 

Hopkins, M.J. 2021

Ontogeny of the Trilobite Elrathia kingii (Meek) and Comparison of Growth Rates Between Elrathia kingii and Aulacopleura koninckii (Barrande).

Papers in Palaeontology, 7(2):985-1002  PDF LINK