Oxalaia quilombensis

Oxalaia was a relatively recently discovered genus of spinosaurid dinosaur, named in 2011 from fossils found in the Alcântara Formation of northeastern Brazil. The partial remains, including parts of the skull, suggest that Oxalaia was a massive predator, with an estimated length of up to 12-14 meters, making it one of the largest known spinosaurids, possibly rivaling or exceeding Spinosaurus in size. Like other members of the Spinosauridae family, it likely had a long, narrow skull with conical teeth, ideal for catching fish, which indicates that it might have had a semi-aquatic lifestyle, feeding in rivers, lakes, or coastal environments.

The spinosaurid family, including Oxalaia, is distinguished by their elongated, sail-like structures on their backs, though it is unclear if Oxalaia had such a sail, as the fossil evidence does not preserve this feature. However, it’s possible that it had a similar structure, used either for thermoregulation or display. Oxalaia likely coexisted with other large predators in the region, including theropods and crocodile-like reptiles, and would have been a top predator in its ecosystem, hunting both large terrestrial prey and aquatic animals.

Despite its impressive size and specialized features, much about its behavior, ecology, and exact place in the evolutionary tree of spinosaurids remains speculative, as the fossil record for this particular dinosaur is still limited. Nonetheless, Oxalaia offers a fascinating glimpse into the diverse and unique predatory strategies of Cretaceous theropods.