Ancient "Great Indo-Australian Miocene Reef System" Dwarfs Modern Coral Reefs
A study led by Dr. Alexandre Siqueira from Edith Cowan University (ECU) has identified a period of extensive coral reef growth that occurred between 20 and 10 million years ago in the region now known as the Indo-Australian Archipelago.
The research, published in Science Advances, describes this as the largest expansion of coral reefs in the past 100 million years.
Key Findings
The study identifies a massive reef system that existed during the Miocene epoch (20-10 million years ago) off Australia's northwest coast. Researchers have termed this ancient structure the "Great Indo-Australian Miocene Reef System."
According to the study, individual reefs within this system may have been larger than any modern reef.
Methodology and Evidence
The research combined three independent data sources:
- Geological records and maps of ancient reefs
- Fossil evidence
- Genetic data from modern reef species
The study states that changes in environmental, biological, and tectonic conditions approximately 20 million years ago promoted the expansion of coral reefs. This period coincides with tectonic plate movements that opened shallow, warm seas. Genetic studies on parrotfish and wrasses indicate rapid diversification of reef lineages during the same period.
Modern Remnants
According to the study, remnants of this ancient system may exist off northwestern Australia, including Ashmore Reef, Scott Reef, and the Rowley Shoals.
The research suggests these modern reefs may have been part of a barrier reef system that rivaled the present-day Great Barrier Reef in extent.
Statements from Researchers
Dr. Siqueira stated that the research shows a turning point in Earth's history when reefs grew on a scale beyond what is seen today. He added that the findings suggest the roots of modern marine fish and coral biodiversity lie off Australia's west coast, with biodiversity spreading over millions of years.
Dr. Siqueira described the findings as "one more piece of evidence to the puzzle on how coral reef systems as a whole evolved."
Publication
The study, titled "The rise and fall of the world’s greatest marine biodiversity hotspot," was published in Science Advances.