{{Short description|Extinct genus of trilobites}} {{Automatic taxobox | fossil_range = {{fossilrange|461|466}} | image = TrinucleusFimbriatus_AAScaife.jpg | image_caption = ''Trinucleus fimbriatus'' | taxon = Trinucleus | authority = Murchison, 1839 | subdivision_ranks = Species | subdivision = }}
'''''Trinucleus''''' is a genus of trilobites of the order Asaphida. It is in the family Trinucleidae.<ref>{{Cite web|url=https://www.3d-fossils.ac.uk/fossilType.cfm?typSampleId=3244|title=Trinucleus UK Trinucleid Trilobite}}</ref>
Fossil specimens are found in the Ordovician rocks of Powys, Wales.
This trilobite was blind and although the exact function of the pits and bars surrounding the cephalon are unknown, anatomical evidence suggests this trilobite sifted organic matter on the seabed.
The specimen shown has the lower side of the rostral plate and genal spines displaced from the cephalon.
==References== {{Reflist}}
{{Taxonbar|from=Q4970089}}
Category:Trinucleidae Category:Asaphida genera Category:Fossils of Great Britain Category:Ordovician trilobites Category:Taxa named by Roderick Murchison
{{Asaphida-stub}}