A team of researchers said that they have discovered the first ever remains of microscopic kinorhynch worms which are commonly known as mud dragons. The fossils were found in China and are almost 530 million years old.

According to the researchers, the very first fossil belonging to the species was excavated in 2013 in rocks in Nanjiang, China, and later they found some more fossils in 2014.

The researchers strongly hope this historic find will help to fill a huge gap in the known fossil record of kinorhynchs, small invertebrate animals that are related to arthropods, featuring exoskeletons and segmented bodies, but not jointed legs.

The newly discovered animal dates back to the Cambrian period and contains five pairs of large bilaterally placed spines on its trunk and is believed to be related to modern kinorhynchs.

Shuhai Xiao, a professor at the College of Science at Virginia Tech in US, said, “Kinos represent animal group that is related to arthropods - insects, shrimps, spiders, - which are most diverse group of animals on planet. Although arthropod fossils date back to more than 530 million years ago, no kino fossils have ever been reported”.

Xiao further said that the new fossil can help scientists know more on how and why body segmentation evolved many times among arthropods, and several other groups of animals.

There are approximately 240 living kinorhynch species, all found in marine environments. The body of kinorhynchs is divided into three sections i.e. a head, which includes a mouth cone with teeth; a neck; and a trunk with 11 segments, said researchers.