How Massive Long-Necked Dinosaurs Dominated the Middle & Late Jurassic

Dinosaurs have marveled us since archeologists first began studying their fossils. The long-necked sauropods were the largest animals to ever walk on Earth. A new study suggests that they rose to rule the Jurassic herbivores during the Jurassic period due to a period of significant volcanic activity.

An illustration of the newly discovered Bagualia alba, one of the oldest true sauropod fossils ever discovered, dating to 179 million years ago. B. alba had powerful jaws, long neck, and an oversized gut.
How Massive Long-Necked Dinosaurs Dominated the Middle & Late Jurassic

How The Long-Necked Sauropods Rose to Dominance

New archeological findings in Argentinian Patagonia carried out by paleontologist Diego Pol and his colleagues from the Paleontological Museum Egidio Feruglio in Trelew, Argentina, uncovered a new type of dinosaur called Bagualia alba. The fossils are dated back to precisely 179 million years ago, which is roughly the beginning of the Middle Jurassic period. Researchers found that B. alba had the prominent characteristics of true sauropods: massive size, column-like legs, incredibly long necks, spoon-shaped teeth, and broad and strong jaws. These characteristics helped them adapt to the changing flora of the time, which many other dinosaurs couldn’t do and therefore went extinct.

The B. Alba Dinosaurs Were Better Equipped for Life in Middle Jurassic

The tooth of Bagualia alba, discovered in Argentinian Patagonia, bears the typical thick enamel and spoon shape of sauropods.
How Massive Long-Necked Dinosaurs Dominated the Middle & Late Jurassic

During the Early Jurassic, plant-based sauropods competed for the same food with many other herbivores that had much smaller jaws and shorter necks. However, a possible explanation as to why many species disappear from fossil records after that period is an environmental crisis that occurred toward the end of the Early Jurassic. There was an episode of global warming and large volcanic eruptions in the Southern Hemisphere that might explain what happened.

Scientists speculate that this abnormal volcanic activity may have led not only to multiple extinctions but also to a major change in plant life in the region. As a result, conifers began to flourish, and since B. alba sauropods were well-equipped, they could chomp on the very tough leaves of the conifers, and their oversized gut could digest the otherwise tough plant matter, allowing them to continue to feed. Something that was practically impossible for smaller herbivores.