97-million-year-old fossils reveal the earliest known animal “GPS”

Researchers have identified what may be the earliest known evidence of an internal animal "GPS" system, offering a possible glimpse into how modern birds, fish, and other creatures evolved the ability to navigate using Earth's magnetic field.

The evidence comes from tiny magnetic fossils dating back 97 million years. They were preserved in ancient seafloor sediments and appear to have been produced by an organism whose identity remains unknown.

Known as magnetofossils, the microscopic structures come in shapes resembling spearheads, spindles, bullets, and needles. Each is no larger than a bacterial cell. Scientists believe they have a biological origin, although exactly what organism created them and what purpose they served has long remained uncertain.

Now, researchers have uncovered evidence that the structures may have functioned as a sophisticated navigation system, allowing an ancient animal to interpret Earth's magnetic field much like a map.