This Amargasaurus fossil is really fascinating. Known from only one skeleton that was mostly complete, it has a unique feature of two parallel rows of tall spines down its body.

A long time ago people thought that these spines supported a sail, but now it is thought they were defensive structures that jutted out of the body.

One part that was missing was most of the skull, so this is an assumption of what it looked like.

Museum Monday is an every other week series about museum news, objects, and reviews.