NANJING, April 28 (Xinhua) -- A team of Chinese and British researchers has found the fossil of a spiky freshwater arthropod named Maldybulakia saierensis in northwest China's Xinjiang Uygur Autonomous Region, pushing back the earliest appearance of the species to about 420 million years ago.
It is the oldest body fossil record of a freshwater arthropod found in China, said researchers from Nanjing Institute of Geology and Palaeontology under the Chinese Academy of Sciences. The results were published in Papers in Palaeontology.
The Maldybulakia saierensis looks like a strange insect with thorns all over it. Its body has multiple segments which extend symmetrical spikes to both sides, and the tail part trails a slender tail spike.
After analyzing the paleosalinity and other data on the fossil site, the researchers concluded that the arthropod had been living in a freshwater environment such as mountainous rivers or lakes.
Arthropod is the largest phylum in the animal kingdom, ranging from shrimps and crabs living in seawater and freshwater to mosquitoes, flies and spiders on the land, said Xu Honghe, lead author of the research from the institute.
Xu noted that the emergence of freshwater arthropods is a crucial transitional link in the "landing" of marine animals. The discovery of the fossil provides important evidence to understand how animals move from the ocean to land. ■
