Many long-necked dinosaurs, or sauropods, had pretty bizarre features: The armor-plating on Saltasaurus, the club-tail on Shunosaurus, and the weird, vacuum-like mouth on Africa’s Nigersaurus. And then you’ve got Amagarasaurus, whose neck has been baffling scientists for decades.

1. Amargasaurus’ Neck Spines Might Have Supported a Pair of Sails.  

Strange, rod-like structures projected upwards from its vertebrae, with the tallest being nearly 2 feet. One formerly-popular idea posited that they were covered by a thin layer of skin, forming two parallel fans. However, if such accessories existed, they would probably have stiffened Amargasaurus’ neck.

2. … Or, Maybe They Were Used for Protection.

It’s also possible that, in lieu of webbing, each spine boasted a long, horny sheath with a pointed tip. By bending its head downward, some theorize, Amargasaurus could aim them at oncoming predators and hope that the display proved sufficiently scary-looking.

3. Another Idea is that Amargasaurus Banged Them Together Like a Percussion Instrument.  

Paleo-artist Gregory S. Paul speculates that when Amargasaurus shook its neck, those spikes smacked into each other, producing a loud, threatening noise.  

4. It Was Denied an Appearance in Disney’s Dinosaur (2000).

To this movie’s credit, it cast some rather obscure animals—instead of, say, T. rex, the villain was a devil-horned meat-eater named Carnotaurus. But a number of other dinosaurs were cut during pre-production. Concept artist Ricardo Delgado submitted an Amargasaurus design complete with giraffe-style spots, but the sauropod never made it on screen.

5. Amargasaurus is Named After Argentina’s La Amarga Rock Formation.

Located in the oil-rich Neuquen Basin, the outcropping is approximately 120 million years old. Amargasaurus was first unearthed there (near La Amarga, a namesake town) in 1991 by accomplished paleontologist José Bonaparte.

6. By Sauropod Standards, its Neck Was Pretty Short.

Some, like Mamenchisaurus, had huge necks that were about as long as the rest of their bodies. Amargasaurus wasn’t nearly so well-endowed. This South American critter belonged to the dicraeosauridae family, whose members were noted for their comparatively-diminutive necks.

7. It’s Related to Some of the World’s Most Famous Dinosaurs.

Dicraeosaurids are classified as diplodocoids, a large group that also includes Diplodocus (whose replicated bones are on display in museums all over the world) and the ever-popular Brontosaurus.

8. Amargasaurus Had Unusual Backbones.

Its neck gets all the attention, but Amargasaurus also rocked tall, paddle-shaped spines on its back vertebrae. Again, nobody knows what these did (or if, indeed, they served any function at all).

9. The Melbourne Museum has an Amargasaurus Replica Named Margie.

This full-sized skeletal cast used to spend her free time “writing” for the museum’s official blog (check out this adorable post about Margie’s Christmas attire).

10. According to a Recent Skull Analysis, Amargasaurus Was Well-Suited for Browsing.

Last year, paleontologists Ariana Carabajal, José Carballido, and Philip J. Currie published a report on Amargasaurus’ brain cavity. Their study concluded that, in general, this sauropod mostly pointed its muzzle towards the ground. Given this habit and its modest neck, Amargasaurus was seemingly built for nibbling on mid-level vegetation like tall shrubs.