2 in notes

ikfiio fu'ivla

x₁ is a icthyosaur [member of order Ichthyosauria] of subtaxon/type/genus/species/variety/breed x₂.

See also: dinso, dinsauru, plesiio, disrmuzo, rexsa, ketslau.

• jbovlaste

In notes:

dinso

x₁ is a 'dinosaur' [very general: any ancient quasi-reptilian vertebrate or, possibly but probably not, modern bird] of type x₂ living in era x₃.

plesiio

x₁ is a plesiosaur [member of order Plesiosauria] of subtaxon/type/genus/species/variety/breed x₂.