New research from Cambridge and the Helmholtz-Zentrum Berlin has decoded the mystery of magnetic fossils left by an ancient organism.<\/p>\n
These microscopic, spearhead- or needle-shaped magnetic fragments were found in ancient seafloor sediments dating back up to 97 million years.<\/p>\n
It turns out, these ancient remnants were the biological \u201cGPS system\u201d left behind, likely by an ancient eel-like creature. This internal compass allowed the unidentified creature to navigate using Earth\u2019s magnetic field precisely.<\/p>\n
\u201cWhatever creature made these magnetofossils, we now know it was most likely capable of accurate navigation,\u201d said Rich Harrison from Cambridge\u2019s Department of Earth Sciences, who co-led the research.<\/p>\n
\u201cIt looks like this creature was carefully controlling the shape and structure of these fossils, and we wanted to know why,\u201d Harrison stated.<\/p>\n
3D imaging of the tiny fossils <\/p>\n
Magnetoreception<\/a> \u2014 the ability to sense and utilize the Earth\u2019s magnetic field \u2014 is a well-documented but still partly enigmatic sense found in the animal kingdom today.<\/p>\n Many species, like migratory birds<\/a>, sea turtles, rely on this invisible global grid for long-distance navigation, orientation, and even hunting.<\/p>\n It has been proposed that tiny, internal magnetite crystals act as microscopic compass needles, aligning themselves with the Earth\u2019s magnetic field<\/a>.<\/p>\n However, little is known about how ancient organisms used this internal compass, or whether it was even present millions of years ago.\u00a0<\/p>\n These new magnetofossils, which are \u201cno larger than a bacterial cell\u201d, offer the first direct evidence of ancient animals using the geomagnetic field for navigation.<\/p>\n It showcases that animals have been using the magnetic field as a map for nearly 100 million years.<\/p>\n For this study, the team used a new 3D magnetic imaging technique to peer inside these minuscule fossils for the first time.<\/p>\n Interestingly, the 3D images of the fossil\u2019s magnetic structure revealed features optimized to guide long-distance migration by detecting the direction and strength of the planet\u2019s magnetic field.<\/p>\n Search for fossils\u2019 real creator <\/p>\n The technique enabled visualization of the fossil\u2019s internal structure. It showcased the arrangement of its \u201cmagnetic moments\u201d \u2014 tiny magnetic fields generated by spinning electrons \u2014 swirled in a vortex pattern, much like a miniature tornado.\u00a0<\/p>\n This unique configuration, dubbed \u201cvortex magnetism,\u201d is the key to its navigational prowess.<\/p>\n \u201cThis magnetic particle not only detects latitude by sensing the tilt of Earth\u2019s magnetic field but also measures its strength, which can change with longitude,\u201d said<\/a> Harrison.<\/p>\n He likened the process to a subtle \u201cwobble\u201d in the magnetic field, providing the organism with detailed map information. The stability of this vortex structure also meant it could resist environmental disturbances, making it a highly reliable guidance system.<\/p>\n \u201cIf nature developed a GPS, a particle that can be relied upon to navigate thousands of kilometres across the ocean, then it would be something like this,\u201d the author added.\u00a0<\/p>\n Solving the mystery of the fossils\u2019 function allows the research to focus the search for their creator.\u00a0<\/p>\n Earlier, it was assumed that an ancient bacteria<\/a>-like creature likely left behind these magnetic remnants. However, it was not proven.\u00a0<\/p>\n Researchers are now seeking a migratory marine animal, abundant in ancient oceans, that may have possessed such sophisticated internal navigation. One compelling candidate? Eels.<\/p>\n These enigmatic creatures evolved around the same time and are known for epic transoceanic migrations. Experts have long suspected that eels use the\u00a0Earth<\/a>\u2018s magnetic field, though the precise mechanism has\u00a0remained elusive.<\/p>\n The findings could advance our understanding of how life evolved its most elusive sense of magnetoreception.<\/p>\n