Diania

Diania is an extinct genus of animal found in the Lower Cambrian Maotianshan shale of China, represented by a single species D. cactiformis. Known during its investigation by the nickname "walking cactus", this organism belongs to a group known as the armoured lobopodians and has a simple worm-like body with robust, spiny, and apparently jointed legs. Its significance is that jointed legs are the defining character of the arthropods and Diania may thus be very close to the origins of the most diverse group of animals on the planet.

Discovery
Fossil of these animals were discovered independently by Jianni Liu from the Northwest University (China) in Xi’an, Qiang Ou from the China University of Geosciences in Beijing and Michael Steiner of the Free University Berlin. The fossils come from the famous Chengjiang deposit – or Maotianshan shale – of south-west China and are about 520 million years old. Specifically, they come from the Yu'anshan Formation, dated to the Cambrian Stage 3.

Name
The name Diania comes from "Dian", which is an abbreviation in the Chinese language for Yunnan; the province where the fossils were discovered. The specific epithet cactiformis is based on its cactus-like appearance, which led to it being informally called the "walking cactus" by the research team working on the fossils.