New dinosaur discovery in Argentina reveals the wondrous world of the Late Cretaceous

In Patagonia, scientists have recently discovered a new species of dinosaur named Koleken inakayali, a member of the Abelisauridae group, carnivores known for their characteristic short forelimbs. The name Koleken inakayali comes from the language of the Tehuelche people from central Patagonia, inspired by the site of discovery in clay layers and the name of the leader of the Tehuelche people, Inakayal. This discovery represents only the second known species of Abelisauridae that lived in the La Colonia formation during the Late Cretaceous, approximately 70 million years ago. Surprisingly, Koleken coexisted with other dinosaurs like Titanomachya gimenezi, suggesting that the La Colonia formation was a key point for studying the last years of dinosaurs.

Koleken inakayali shows a relationship with the well-known "meat bull" Carnotaurus sastrei, but unlike this more famous relative, Koleken is smaller and lacks massive frontal horns. Its skull and anatomical features reveal new insights into the diversity of Abelisauridae, making this discovery extremely important for understanding the predators that lived in South America before the mass extinction at the end of the Cretaceous.

The research team, led by National Geographic Explorer Diego Pol, found a partial skeleton of Koleken, which includes several skull bones, nearly a complete series of vertebrae, a complete hip, several tail bones, and nearly completely preserved legs. These findings provide a rich source of information about the biological diversity and evolution of predators during the Late Cretaceous. Interestingly, Koleken's skull shows accelerated rates of evolution in the early Cretaceous, further explaining how they adapted to changing environmental conditions.

Patagonia as a hotspot for Abelisauridae diversity

Patagonia has long been considered a key area for discovering Abelisauridae fossils, and the discovery of Koleken confirms its importance. Most Abelisauridae fossils have been found in southern Argentina, while the northern part of this region remains relatively unexplored. The discovery of this new species, particularly in the Los Blanquitos formation in northern Argentina, opens doors for further research on how this group of predators adapted to life in various areas. The skull of Guemesia ochoai, found in the same area, provides important information about the evolutionary characteristics of these dinosaurs, even in the absence of the characteristic horns found in other Abelisauridae. This unique feature suggests a possible closeness to the ancestors of the entire group or its position at the base of the Abelisauridae family tree.

Despite certain ambiguities, such as brain size and physical characteristics that differentiate Guemesia ochoai from other Abelisauridae, researchers believe these characteristics indicate the existence of a new genus and species. Guemesia ochoai was named after the Argentine folk hero Martín Miguel de Güemes and museum technician Javier Ochoai, who discovered the fossil. Researchers now hope to find additional specimens to learn more about life in ancient Argentina, especially during the period preceding the mass extinction at the end of the Cretaceous.

Diversity of fauna in the La Colonia formation

The La Colonia formation, located in central Patagonia, has become known as one of the most important fossil sites from the Late Cretaceous. Here, in addition to Koleken, remains of other dinosaur species have been found, such as titanosaurs that coexisted with Abelisauridae. Scientists believe these sites are crucial for understanding the ecosystems that existed just before the great mass extinction. Along with dinosaurs, remains of animals such as podocnemid turtles have been found, indicating a diverse community of terrestrial and aquatic species that lived here.

The diversity of Abelisauridae in the La Colonia formation reflects not only the richness of the ecosystem but also the speed of evolutionary changes that led to adaptations necessary for survival in the unpredictable conditions of the Late Cretaceous. Researchers have focused particular attention on studying the evolution of skull structures that indicated various adaptations to predation. Koleken's evolutionary adaptations, such as the robust skull structure and strong jaws, demonstrate how these dinosaurs were ready to adapt to their ecosystem, despite the lack of typical forelimbs.

Scientists now plan further research to learn more about the life and death of dinosaurs like Koleken and to better understand extinction patterns in South America and compare them with the rest of the world. Diego Pol and his team of global experts continue to work on gathering new fossil evidence that will allow them to gain a more detailed understanding of the last moments of dinosaurs.

The discovery of Koleken and other related species not only enriches our knowledge of the diversity of animal life in Patagonia but also allows us to better understand the global changes that shaped our planet. The investigation of these fossils is something that transcends national boundaries; it contributes to the global scientific community and gives us insight into how dinosaurs lived, died, and ultimately disappeared from the face of the Earth during one of the most dramatic chapters of our planetary history.