1892 H. M. Bernard xiii. 216 Strictly speaking the ridge and the shield were two independent developments of the primitive Trilobitan head-shield.
1958 33 42/1 The Merostomata lost the trilobitan antennae.
1993 E. N. K. Clarkson (ed. 3) xii. 400/1 It has..uniramous antennae and typically trilobitan appendages.