Superficially similar to T. flavomarginata (q.v.) but thicker in form, with wider yellow margins on sides of pronotum and lacking the short yellow strip below the scutellum. Also, pronotum is shinier with finer puncturation and lacks the coarser sculpturing of T. flavomarginata.

The colouration of this species is variable. The forms with yellow margins, which seem to predominate in SA, were previously treated on these pages as T. cf. marginalis.

The individual with red margins shown here is somewhat atypical in its broader shape. In the original description by Carter 1929b based on material from WA, he states: 'the pronotum very nitid and glabrous, with an orange margin not extending to base; elytra dark brown, becoming reddish-brown towards apex, with an orange margin throughout'.

Individuals collected on upper Eyre Peninsula vary greatly in the extent of the pigmented vs pale/testaceous colouration of abdominal ventrites, even within a single site.

An unusual specimen (PL6345) collected in Barmera on the River Murray appears closest to this species and is provisionally included here. As well as its pale colouration, it is notable for having black tips on the elytral apices, a feature that is also seen on one specimen of T. marginalis from Round Hill in NSW.