Fossils and Extinction: The Role of Coastline Orientation (2026)

Fossil Evidence Reveals Latitudinal Traps Heightening Extinction Risk

A groundbreaking study led by researchers at the University of Oxford has uncovered a fascinating connection between coastline geometry and extinction patterns over the past 540 million years. The research, published in the prestigious journal Science, reveals that the shape and orientation of coastlines significantly impact the survival chances of marine animals. Specifically, animals living on convoluted or east-west-oriented coastlines are more susceptible to extinction compared to those dwelling on north-south-oriented coastlines.

The study's lead author, Dr. Cooper Malanoski, emphasizes the importance of palaeogeography in understanding mass extinctions. He explains that certain continental configurations may hinder species' ability to escape extreme climate changes, leading to more severe extinctions. Co-author Professor Erin Saupe adds that north-south-oriented coastlines provide a crucial advantage during climate change, allowing species to migrate and maintain their ideal temperature tolerance range, thus reducing extinction risk.

The research team analyzed over 300,000 fossils of marine invertebrates, spanning 12,000 genera, and combined this with historical continental reconstructions. Their statistical model confirmed the hypothesis that coastline orientation and shape influence extinction likelihood. Invertebrates in environments like east-west coastlines, islands, or inland seas, where latitude migration is challenging or impossible, are consistently more vulnerable to extinction.

This discovery has significant implications for modern conservation efforts. Species in isolated habitats that cannot easily migrate to different latitudes may be at higher risk due to anthropogenic climate change. The findings highlight the need to consider palaeogeographic context when prioritizing conservation and identifying vulnerable marine populations, especially those crucial for ecosystem services.

The study, conducted in collaboration with various institutions, including the University of California, Berkeley, Stanford University, the University of Leeds, and the Smithsonian Tropical Research Institute, has been published in Science. It underscores the critical role of latitude migration in species survival and the potential long-term consequences of climate change on marine ecosystems.