For decades, paleontologists have believed that the very first dinosaurs evolved in the southern parts of the ancient supercontinent Gondwana, specifically in what is now Argentina. This theory was largely based on fossil discoveries in the region, where species like Eoraptor and Herrerasaurus were uncovered.
These findings shaped the conventional wisdom about dinosaur origins. However, a recent study challenges this long-held assumption, proposing that the true birthplace of dinosaurs might lie in a different region.
Reassessing Dinosaur Origins
The study, conducted by a team of scientists from University College London (UCL), published in the journal Current Biology, casts doubt on the prevailing view of dinosaur evolution. Researchers employed a novel approach using a computer model to analyze the gaps in the fossil record and explore how early dinosaur species were related to one another.
The results pointed to a new region as the likely birthplace of dinosaurs. According to the study, the first dinosaurs could have emerged in the northern sections of Gondwana, which would correspond to regions in modern-day Africa and South America.
These findings stand in contrast to the traditional belief that southern Gondwana, which is now part of Argentina, was the primary area where dinosaurs first evolved. The shift in perspective suggests that paleontologists may need to direct future fossil searches toward these northern parts of Gondwana.
However, these areas, such as the Sahara Desert and the Amazon Rainforest, are not only remote but also present challenging environments for paleontologists to explore.
New Discoveries That Challenge Established Views
Recent fossil discoveries are fueling the debate about where dinosaurs originated. One such find is Nyasasaurus, a potential dinosauriform species unearthed in Tanzania. Described in a 2013 scientific paper, Nyasasaurus was found in rock layers from the Anisian stage of the Middle Triassic period, roughly 247 to 241 million years ago.
If Nyasasaurus is indeed a true dinosaur, it would be the oldest known dinosaur species discovered to date, pushing back the timeline for dinosaur evolution even further than previously thought.
Another important find is Ahvaytum, a sauropodomorph species discovered in Wyoming. Dating back to the Carnian stage of the Triassic period, Ahvaytum provides new insights into the early stages of dinosaur evolution. This species is particularly significant because it represents one of the earliest dinosaurs found in North America.
These recent discoveries, including Nyasasaurus and Ahvaytum, challenge the idea that dinosaurs first evolved exclusively in the southern regions of Gondwana.
A New Focus for Future Expeditions
The results of this study suggest that paleontologists need to reconsider where they focus their research efforts. The team at UCL has emphasized that the northern parts of Gondwana, specifically areas that now make up parts of Africa and South America, may hold the key to uncovering the earliest dinosaur fossils.
These regions, while rich in potential for important discoveries, are less explored due to their harsh environments. The Sahara Desert and the dense Amazon Rainforest are notoriously difficult to access, which could explain why fewer expeditions have been carried out there.
According to Joel Heath, the lead author of the study, “Today, this region constitutes the northern parts of Africa and South America. Paleontological expeditions to these regions may be less common as a result of the harsh environment of the Sahara and inaccessibility of many areas of the Amazon.”
These challenges, however, should not deter paleontologists from focusing on these areas in future research. If successful, these expeditions could yield fossil evidence that will rewrite the history of dinosaur evolution.
