A fossilized spinosaur tooth, estimated to be 66 million years old, has been discovered in Peru, marking the first physical evidence of these ancient predators in the region. The find, cataloged as MUSM 5121, is a significant contribution to understanding the distribution of spinosaurids.
The tooth's distinctive features—a thin crown with two keels, a circular cross-section, rough enamel, and longitudinal striations—were confirmed by Rodolfo Salas-Gismondi, head of the Vertebrate Paleontology Department at the Natural History Museum of the National University of San Marcos. These characteristics are hallmarks of the Spinosauridae family, aligning the fossil with known spinosaurs like Spinosaurus aegyptiacus from Africa.
The presence of spinosaurids in Peru suggests ancient sea connections between Africa and western South America, likely facilitated through the Peruvian Amazon. Spinosaurids were semi-aquatic hunters, recognizable by their long, crocodile-like snouts and conical teeth adapted for grasping fish. While the exact genus of the Peruvian fossil is yet to be determined, spinosaurs are primarily known from Africa, eastern Brazil, and Europe, making this discovery a key piece in understanding their South American presence.
These formidable predators inhabited the Earth during the Late Cretaceous period, a time of significant dinosaur evolution approximately 80 to 66 million years ago. This timeframe is notable, as most spinosaur remains globally date to earlier parts of the Cretaceous. The find highlights the paleontological potential of Peru's Bagua Grande region for uncovering fossils from the end of the dinosaur era.
Historically, Peru's incomplete fossil record for dinosaurs has been attributed to geological factors, including extensive periods of the landmass being submerged under the sea during the Cretaceous, limiting terrestrial habitats. Additionally, a lack of widespread exploration in Cretaceous rock formations has contributed to this scarcity. While fossil footprints are more common in Peru, they are preserved in different geological environments than skeletal remains, which require higher-energy conditions for better preservation.
This discovery not only enriches the understanding of prehistoric fauna in South America but also underscores the growing importance of the Amazon region in paleontological research. The presence of spinosaurids in Peru adds a new dimension to their known distribution, suggesting a broader ancient ecosystem than previously understood.