"Agustinia ligabuei" was well known for its distinctive supposed armor plates (osteoderms), initially interpreted as a series of wide, vertical spikes and plates down the center of its back, somewhat like the unrelated "Stegosaurus". However, subsequent research has challenged the nature of these osteoderms. Further study of the poorly preserved fossil material showed that these "plates" were in fact more likely to be fragments of ribs and hip bones. This reassessment was reaffirmed subsequently by histology of the purported osteoderms, which do not match the internal structure of other titanosaurian osteoderms. The fragmentary hip bone was tentatively identified as part of the ilium.