AsianScientist (Jun. 19, 2018) – In a study published in Science Advances, researchers in China and the US have found evidence of the earliest animal footprints on Earth.
On July 20, 1969, Neil Armstrong put the first footprint on the moon. But when did animals leave the first footprint on Earth? An international research team consisting of researchers from China and US may have found answers to this question.
Bilaterian animals such as arthropods and annelids have paired appendages and are among the most diverse animals today and in the geological past. They are often assumed to have appeared suddenly during the Cambrian explosion, which occurred about 541-510 million years ago, although it has long been suspected that their evolutionary ancestry was rooted in the Ediacaran Period.
In this study, the scientists reported their discovery of fossil footprints made by the appendages of animals that lived during the Ediacaran Period (about 635-541 million years ago) in China.
Researchers from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences and Virginia Polytechnic Institute and State University in the US studied trackways and burrows discovered in the Ediacaran Shibantan Member of the Dengying Formation (551-541 million years ago) in the Yangtze Gorges area of South China. The trackways are somewhat irregular, consisting of two rows of imprints that are arranged in series or repeated groups.
The characteristics of the trackways indicate that they were produced by bilaterian animals with paired appendages that raised the animal body above the water-sediment interface. The trackways appear to be connected to burrows, suggesting that the animals may have periodically dug into sediments and microbial mats, perhaps to mine oxygen and food.
This is considered the earliest animal fossil footprint record. The body fossils of the animals that made these traces, however, have not yet been found.
The article can be found at: Chen et al. (2018) Late Ediacaran Trackways Produced by Bilaterian Animals With Paired Appendages.
Source: Chinese Academy of Sciences; Photo: Nanjing Institute of Geology and Paleontology.
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