Evolution of the oldest segmented animal revealed in fossilized death march. A team of international researchers have discovered a fossil that may be one of the oldest mobile and segmented animals ever to exist on Earth.
The fossilized death march of the bilaterally symmetrical animal (dubbed “bilaterian”) was found in a 550-million-year-old rock in China, placing its existence in the Ediacaran Period (635-539 million years ago).
The research was performed by scientists from the Nanjing Institute of Geology and Paleontology of the Chinese Academy of Sciences and Virginia Tech
The evolution of bilaterians with segmented body parts is a huge event in early animal evolution, and this discovery, called Yilingia spiciformis, is the first piece of evidence to show that this evolution occurred during the Ediacaran Period, as previously estimated.
This fossil is especially unusual because of the connected and preserved trail it made while it moved across the earth. This animal-and-trail connection helps scientists understand the producers of other Ediacaran trace fossils. Evolution of the oldest segmented animal revealed in fossilized death march
Yilingia spiciformis is believed to have been capable of locomotion, and evidence of body segmentation, polarity, and directional locomotion points to Yilingia spiciformis being a bilaterian animal, despite scientists being unable to place it within the bilaterian family tree.
This discovery, published in Nature, will help scientists better understand the origin of segmentation and animal motility, which led to the Cambrian substrate and agronomic revolutions.
By Olivia Harvey, Earth.com Staff Writer
Image Credit: NIGPAS