T. rothi is a Late Miocene thylacinid that was found at the Alcoota Scientific Reserve (Alcoota Local Fauna), Northern Territory.  Its specific name honors Karl Roth for his contributions to the natural history of central Australia.  The holotype specimen is a left maxillary fragment containing P2 and damaged M1-4.  It was reassembled from a concentration of small bone and tooth fragments which according to Murray and Megirian (2002) may represent the contents of a crocodilian coprolite (fossilized dropping).  Many of the fragments exhibit chemical erosion and bear a coating of calcite. Tyarrpecinus is considered to be more closely related to species of Thylacinus than to other thylacinid genera.  Possibly, T. rothi lived contemporarily in the same habitat as the much larger and more derived Thylacinus potens, which is also known from the Alcoota Local Fauna.

    An isolated premolar, discovered in 1971 at the Leaf Locality of the Wipijiri Formation, Lake Ngapakaldi, Etadunna Station, South Australia, would appear to represent a thylacinid.  The fauna of the Leaf Locality is called the Kutjamarpu Local Fauna (Stirton et al.1967) is of Miocene age, and is interpreted by Woodburne to be approximately 12 million years old.