The holotype (UBGD 30550) consists of the animal's posterior region preserved in ventral view, including the telson, uropods and last three segments of the pleon.

Archaeocaris vermiformis Archaeocaris graffhami †Bairdops elegans Perimecturus parki Perimecturus rapax †Bairdops beargulchensis †Daidal pattoni †Daidal schoellmanni †Daidal acanthocercus Gorgonophontes fraiponti Gorgonophontes peleron †Chabardella spinosa †Tyrannophontes theridion †Tyrannophontes gigantion †Triassosculda ahyongi †Tyrannosculda laurae †Pseudosculda laevis †Archaeosculda phoenicia †Sculda pennata †Sculda syriaca †Ursquilla yehoachi †Lysiosquilla nkporoensis †Nodosculda fisherorum Squilla mantis

Triassosculda was discovered in deposits of Paris Canyon, Idaho, dating back to the earliest Spathian age of the early Triassic period, around 250.6 million years ago.

It is part of a diverse fossil assemblage known as the Paris biota, which would have lived in a shallow inland sea on the western coast of Pangaea near the equator.

[3][4] Many other fossil animals are also parts of the Paris biota and would have lived alongside Triassosculda, including other crustaceans, thylacocephalans, ammonoids, nautiloids, bivalves and fish.