LONDON, May 10 (Xinhua) -- An international team of scientists from England, Germany and Spain, uncovered Wednesday the amazing story of a 150 million year old fossil "squid."
The team, led by palaeontologist Dean Lomax, from the University of Manchester, have digitally recreated the fossil using 3D modelling technology.
The fossil is an ammonite, a type of prehistoric cephalopod related to squid and octopuses, found across the globe.
What makes this ammonite stand out is the 8.5 meter long drag mark it has left behind. The ammonite was already dead when the drag mark was made, making it an extremely rare find, according to the researchers.
The study specimen is a species called Subplanites rueppellianus, which was collected from the historically important Late Jurassic Solnhofen Limestones of Germany, famous for its fossil preservation.
Lead researcher Lomax explained: "With fossils, we usually find body fossils, such as bones, teeth or shells, or trace fossils, such as tracks and burrows. However, the drag mark has not been made by the ammonite in life and does not reflect behavior. Instead, the drag mark was created by the lake's current moving the ammonite shell. It is easy to understand why such fossils have been misinterpreted as the traces of living organisms."
"A trace and its maker preserved together in the fossil record are rare. Rarer still are marks created by dead animals together with the animal that made the mark. So, how exactly did the fossil move after it had already died? Ammonites had gas chambers, which they used to control their buoyancy and movement, similar to a submarine," Lomax said.
The scientists believe some of the gas remained present in the shell, which meant it was dragged along the bottom of a tropical lagoon by what must have been a calm and steady current. The mark was created by contact of the ammonites' ribs with the lagoon floor.
Using digital and 3D modelling technologies Lomax and his team have digitally pieced the entire drag mark together to show a close-up of the incredible fossil.
Peter Falkingham, a palaeontologist at Liverpool's John Moores University, and one of the co-authors of this study said: "We created a virtual model of the fossil by compiling over 600 photographs of the specimen. We then created a video, which shows the drag mark and the preserved ammonite. Such modern digitization techniques, like the photogrammetry method we used, have really revolutionized the way palaeontologists can study fossils".
The research has been published in the scientific journal PLOS ONE.
