Scientists Find 530 Million-Year-Old Fossil of Ancient Microscopic Worm

Posted on December 10, 2015

Eokinorhynchus rarus mud dragon

Scientists from Virginia Tech have discovered the 530 million-year-old fossil of an ancient microscopic worm known as a mud dragon. The kinorhynch worm fossil discovery was made in South China. The researchers say it fills a gap in the kinorhynch fossil record.

Kinorhynch worms are related to arthopods. The tiny creatures have armored exoskeletons and segmented bodies. However, they lack jointed legs. The first fossil specimens of the new species was discovered in 2013. The species has been named Eokinorhynchus rarus, which means rare ancient mud dragon.

The ancient creature had five pairs of large bilaterally placed spines on its trunks. The fossilized specimen is about half the size of a grain of rice. The researchers believe it is related to modern kinorhynchs.

Shuhai Xiao, a professor of geobiology in the Department of Geosciences at Virginia Tech, led the research team. Xiao says, "Kinos represent an animal group that is related to arthropods -- insects, shrimps, spiders, etc. -- which are the most diverse group of animals on the planet. Although arthropod fossils date back to more than 530 million years ago, no kino fossils have ever been reported. This is a huge gap in the fossil record, with more than 540 million years of evolutionary history undocumented. Our discovery is the first report of kino fossils."

A research paper on the ancient kino discovery was published here in the journal, Scientific Reports.

Photo: Virginia Tech