(Photo credit Jianni Liu “Walking Cactus from Early Cambrian, China”)
Name: Diania cactiformis
Common Name: Walking Cactus
Family: belongs to the extinct class Xenusia
How it made the Top 10: Although this new species looks more like a cactus than an animal at first glance, Diania cactiformis belongs to an extinct group called the armoured Lobopodia. Like the only living lobopodians (the Onychophora or velvet worms), the armoured lobopodians had wormlike bodies and multiple pairs of legs. D. cactiformis is significant because it has segmented legs adding weight to the theory that arthropods (the largest group of living animals including insects, spiders, and crustacea) evolved from lobopodian ancestors. Stated another way, it looks as if D. cactiformis may share a more recent common ancestor with arthropods than with other lobopodians and that is big news. D. cactiformis is about 6 cm long (2.4 inches) and was discovered in the famous Chengjiang deposit in southwest China in Cambrian deposits about 520 million years old.
Etymology: Diania is named for Dian, a Chinese linguistic abbreviation of Yunnan where the species was found; cactiformis refers to the animal’s cactus-like form.
Type Material: Holotype – Early Life Institute, Northwest University, Xi’an, China.
Type Locality: Yunnan, southwestern China
Reference: Liu, J., Steiner, M., Dunlop, J.A., Keupp, H., Shu, D., Ou, Q., Han, J., Zhang, Z. & Zhang, X. (2011). An armoured Cambrian lobopodian from China with arthropod-like appendages. Nature 470: 526 – 530.