The most recent studies date Dominican amber to the Miocene epoch (15 to 20 million years ago).

T. rex is broadly similar to modern-day hybosorids of genera Apalonychus and Coilodes, sharing their reddish-brown color and a rounded shape.

Manuel Iturralde-Vinent and Ross MacPhee propose that hybosorids may have colonized the islands by walking across a hypothetical land bridge from South America.

[4] Tyranna, which Ratcliffe and Ocampo describe as "the loosely formed stem" of the genus name, comes from the Latin tyrannus, meaning "master" or "tyrannical".

The resulting name, "tyrannical hump", refers to the "possible state of 'mind'" of the holotype specimen when she became fatally trapped in sticky tree sap.

Ratcliffe and Ocampo state that the generic name is similar and the specific epithet identical to those of "another famous, and much larger, species of extinct animal".

The clypeus, a hardened plate on the lower face, has a truncate front edge with curved sides.

The flap-like mouthpart called labrum extends beyond the clypeus, forming a trapezoidal shape and featuring a row of bristles at its center.

They are widest at the middle, with slightly raised bumps near the base of the elytra, called humeral umbones.

[3] Joseph B. Lambert, James S. Frye, and George Poinar, Jr. dated the Dominican amber to Oligocene or Eocene,[6] but later research by Iturralde-Vinent and MacPhee found this to be erroneous and dated all Dominican amber to 15 to 20 million years ago, which corresponds to Miocene.

Ratcliffe and Ocampo presume that it came from the mountain range north of Santiago de los Caballeros, an area where most of the amber mines were situated.