Diania

Live reconstruction

• Maotianshan Slate, China

• Diania cactiformis Liu et al., 2011

Diania is an extinct genus of multicellular animals ( Metazoa ) from the early Cambrian. Fossils of the only known species D. cactiformis, were found in Maotianshan shale in China's Yunnan province and described in 2011 for the first time scientifically. Its scientific name comes from the type species for a Chinese abbreviation Dian for the Yunnan province and on the other his appearance, which resembles a cactus.

Fossil finds

The first description of Diania based on three complete and more than 30 other partially preserved fossils of D. cactiformis from the Maotianshan slate. These members of the Chengjiang fossils were Faunengemeinschaft each other independently discovered by Jianni Liu of the University of Northwest China, Xi'an, Ou Qiang of China University of Geosciences in Beijing and Michael Steiner of the Freie Universität Berlin.

Features

Diania cactiformis was about six inches long and had an elongated, consisting of nine segments of the body. At the forward end of the body there was a trunk. A mouth could not be identified from the fossils, however, there is evidence of a body cavity or intestine. At the little robust body Diania cactiformis was probably ten pairs of armored extremities. These extremities were also segmented and articulated to each other. This reinforced with extensions sclerotized limb segments gave the animal his eponymous cactus -like appearance.

System

Diania is assigned to the Lobopoden, an extinct group meeresbewohnender molting animals ( Ecdysozoa ), the possible ancestors of today's velvet worms ( Onychophora ). At the same time Lobopoden considered as a group of animals in which took place the evolutionary transition from the surrounded by a comparatively soft cuticular integument molting animals armored with a hard exoskeleton arthropods ( Arthropoda ). A cladistic analysis suggests Diania is the sister group of a clade of Schinderhannes and Euarthropoda and thus closely related to the arthropods. His hard-shelled extremities suggest that in the evolution of arthropods was the sclerotization of the extremities ( Arthropodisierung ) before the sclerotization of the body ( Arthrodisierung ).

The systematic position illustrated by the following simplified cladogram:

Cycloneuralia

† Aysheaia

Water bears ( tardigrades )

† Xenusion

† Hallucigenia

Velvet worms ( Onychophora )

† Kerygmachela

† Opabinia

† Anomalocarididae

† Diania

† Schinderhannes

Euarthropoda