Bajadasaurus

Family

Sauropods

Era

Early Cretaceous, between 145 and 132.9 million years ago

Where he lived?

Patagonia, Argentina

Weight

8.000Kg

Height

Length

12m

Bajadasaurus pronuspinax is one of the most distinctive sauropods discovered in recent years. It belonged to the dicraeosaurid group — a family of herbivorous dinosaurs with relatively short necks, related to genera such as Amargasaurus. It lived during the Early Cretaceous, about 140 million years ago, in what is now Patagonia, Argentina.

A short neck… yet extraordinary

Unlike the classic image of long‑necked sauropods, Bajadasaurus had a shorter, more robust neck, typical of dicraeosaurids. What made it truly remarkable was the presence of elongated neural spines projecting from the cervical vertebrae, clearly inclined forward.

These spines, which could exceed 1.30 m in length, were likely covered by soft tissue in life. Still, they are considered relatively fragile, making them unsuitable as direct weapons against predators.

What were its spines for?

The function of these spectacular spines remains debated. Main hypotheses include:

Visual display: they may have helped individuals recognize one another or intimidate rivals.
Passive defense: their forward orientation could have made it harder for a predator to bite the neck.
Sexual selection: they may have played a role in mate attraction, similar to extravagant displays in some modern animals.

Paleontological evidence suggests they were not designed to withstand strong impacts and were unlikely defensive weapons.

Size and general appearance

Bajadasaurus was a medium‑sized sauropod, estimated to reach between 8 and 10 meters in length. It had a robust body, thick weight‑bearing limbs and a long tail that helped with balance. As a herbivore, it fed on low to mid‑level vegetation, such as ferns and conifers.

Discovery and scientific context

Fossils of Bajadasaurus were found at Bajada Colorada in the province of Neuquén, Argentina, and were formally described in 2019. The well‑preserved cervical vertebrae allowed precise identification of spine orientation, a topic previously debated in other dicraeosaurids.

This discovery has helped reinterpret the posture and function of spines in similar dinosaurs, providing fresh insight into sauropod anatomical diversity.

An example of sauropod diversity

Bajadasaurus shows that sauropods were not all the same: some evolved extreme and highly specialized adaptations, reflecting remarkable evolutionary diversity.

Interesting facts about Bajadasaurus

Its spines are among the longest relative to body size of any known sauropod.
It belongs to a poorly represented family in the fossil record.
Its discovery is relatively recent, and research continues to reveal new anatomical insights.
It has changed how scientists interpret the spines of other dicraeosaurids.

A unique crested sauropod of the Cretaceous

Bajadasaurus is an excellent example of how paleontology continues to surprise us. With its unmistakable look and enigmatic spines, it reminds us that there is still much to learn about dinosaurs.

At Dinosaurland, dinosaurs like this help show visitors that prehistory was even more diverse and fascinating than we imagined.