Bajadasaurus

Size and Looks

The Bajadasaurus was a crazy looking dinosaur, it had large spines on its neck that pointed forward. The dinosaur was only found with its skull and a few neck vertebrae so we don’t know exactly what it would have looked like, but we can guess using its relatives like the Amargasaurus. The animal was probably 30-40 ft (6-7 m) and 2-4 tons. The eyes of the Bajadasaurus are very unusual, when the dinosaur leans its neck to feed it would be able to look forward at any potential predators.

Discovery

The Bajadasaurus was found by Dr. Pablo Gallina in Argentina. Specifically in the southern part of the Neuquén province and in the Bajada Colorada Formation. Dr. Gallina was prospecting in the Formation and found some teeth attached to a jaw. Fossils in the Bajada Colorada Formation are very fragile so when the fossil was found Dr. Gallina and others decided to just excavate around the fossils so that they could more carefully uncover the fossils later. After a while of patiently excavating the fossil was uncovered. There was an almost complete skull and a few neck vertebrae. One of these neck vertebrae had a long neural spine on it. Some of the rarest sauropod bones are the skulls, so it is surprising that only the skull and a few neck vertebrae were fossilized because the skulls are one the most fragile bones in sauropods.

Neural Spines

Bajadasaurus had weird spines that were on its neck. The appearance of the neural spines' and their purpose is unknown but there are a few hypotheses that may potentially explain the spines. One hypothesis is that it could have been used as a thermoregulatory sail to keep the dinosaurs' temperatures stable. Another hypothesis is that it may have been just a dorsal hump on its neck. The most supported hypothesis is that the Bajadasaurus spines were long bony horns that stuck out with long keratinous sheaths that extended the length of the spins. This may have just been used as passive defense to keep predators from biting the neck of the dinosaur. The bones have lines on the long neural spine which is a feature that other bones have when covered with keratin. As in the Bajadasaurus when horns are curved the horns are stronger. If the spines ever broke it could potentially kill the animal. The whole neck would have been 6-7 ft long (2 m). These Spines could have been used as sexual display for females. The larger the spines the more females may want to breed with that dinosaur. This would have to be supported by more evidence. When the Bajadasaurus bent down to feed on a plant the spines would have curved down to protect the dinosaur's head.

Environment

The Bajada Colorada Formation is a Formation of red brown sandstone, and it looks pretty much like a desert. But if you go back to the early Cretaceous it would look a little bit like Medano Creek National Park with some more plants. It would have been an environment with many sand dunes. The Bajada Colorada Formation produces markings of sediment that was layered down by water. Their markings are called crossbreeding layers. From these markings we know there were creeks and rivers scattered around the land. The Bajadasaurus would have lived alongside the sauropod Leinkupal, another diplodocid. There have been remains of abelisaurids and possibly dromaeosaurids.

Diet

As you could have guessed the Bajadasaurus was a herbivore and only ate plants. Unlike many sauropods the Bajadasaurus was a low grazer, it would have eaten plants that were low like ferns and horsetails. This adaptation to eating low plants is because of the dicraeosaurs' relatively short necks for sauropods. The Bajadasaurus had small, long, straight or slightly curved teeth for eating these plants and they would have to be pretty efficient for the Bajadasaurus so that it could get the nutrients the dinosaur needed to survive.

Dricraeosauride

The Bajadasaurus belongs to the sauropods. A group of dinosaurs that grew to be one of the largest animals that ever walked the earth. In this group there are tons of smaller groups that branch into smaller groups. Bajadasaurus belongs to the smaller group, the diplodocids, but then they branch off into an even smaller group called the Dicraeosauridea. This group includes sauropods like Amargasaurus, Suuwassea, Lingwulong, Brachytrachelopan, and Dicraeosaurus to name a few. This group is known from South America, North America, Africa, and Asia. This group is characterized by a couple of different features. They have tall forked neural spines on the vertebrae from the neck to the back, they also have short necks for a sauropod.

Sources

Gallina, Pablo A., et al. “A New Long-Spined Dinosaur from Patagonia Sheds Light on Sauropod Defense System.” Nature News, Nature Publishing Group, 4 Feb. 2019,

Bajadasaurus | What Did This Dinosaur Use Its ... - Youtube. https://www.youtube.com/watch?v=_aKrWw79FZI.

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