An Italian "Dragon Bone"?

I first heard about this story from the currently-retired Swedish cryptozoological organisation known as GUST (Global Underwater Search Team), where their founder and leader Jan-Ove Sundberg reported in 2005 that a "dragon bone" hangs in the ceiling of the Medieval church St. George close to the city of Bergamo in northern Italy. The bone is almost two meters (or 170 cm) in length, and according to a local legend it supposedly came from a dragon that was killed by a saint.[1]

Ever since I first got my eyes on it I've kept wondering which animal it might actually belong to. It's very clear that we're looking at one of the animal's ribs, and I remember someone once suggested it came from a bull, but to my knowledge there certainly are no bulls with ribs the size and shape of this one. ​Another individual suggested it came from an elephant, and while elephant ribs are certainly much larger than those of bulls, there are (again) to my knowledge no elephants with ribs the size and shape of this one.

I must also note that we do have examples of old bones from known modern animals such as whales having been falsely claimed as belonging to dragons and so it is entirely possible that the bone could belong to an animal other than a mighty saurian, and I would personally consider whales and dinosaurs to be of appropriate size to own ribs such as this one (it is about as long as a human being after all), and both whales and dinosaurs share a dragon-like appearance (especially in regards to their skeletons). But until it is taken down and properly examined we might never know what animal it actually belongs to (if ever allowed by whatever authorities are in charge of the church).

References:
1. GUST - Global Underwater Search Team "Välkommen till KRYPTOLAND nummer 6, Italien: DRAKBEN HÄNGER I MEDELTIDSKYRKA", Jan-Ove Sundberg, 2005 (link)