Observations on the Terataspis grandis, Hall, the largest known trilobite

The essay surveys reports of exceptionally large trilobites in Paleozoic faunas, comparing measurements and restorations of notable genera and species across Silurian and Devonian deposits. It compiles fragmentary and nearly complete specimens, evaluates reconstructed body proportions from cephalon, thorax, and pygidium elements, and discusses museum holdings and published illustrations. The author emphasizes the extraordinary size and ornamentation of the giant species, traces its occurrences in regional formations, and offers observations on available fragments to refine restorations and better understand the animal's original morphology.