Eucinepeltus was larger than other basal glyptodonts such as Propalaehoplophorus, with a skull reaching 20 centimeters in length, and wider than most of its relative species.

The cephalic shield was composed of 11-15 large welded bony plates, presenting a central convexity often perforated.

The genus Eucinepeltus was first described in 1891 by Florentino Ameghino, based on fossilized remains found in Early Miocene terrains from Argentina.

Eucinepeltus is the largest genus belonging to the Propalaehoplophorini, a tribe of basal glyptodonts, typical of the Early Miocene, and also including the genera Propalaehoplophorus, Parapropalaehoplophorus and Asterostemma.

Cladogram after Barasoain et al. 2022:[1]Boreostemma Glyptotherium Glyptodon Propalaehoplophorus Eucinepeltus Cochlops Palaehoplophorus Kelenkura Eosclerocalyptus Plohophorus Pseudohoplophorus Doedicurus Eleutherocercus Neosclerocalyptus Hoplophorus Propanochthus Panochthus