D defs.my
Entry 1 sense Webster, 1913

Trinucleus

· Tri·nu·cle·us · IPA
01 n. A genus of Lower Silurian trilobites in which the glabella and cheeks form three rounded elevations on the head.
  1. 1.
    A genus of Lower Silurian trilobites in which the glabella and cheeks form three rounded elevations on the head.(Paleon.)