Marrella

Fossil of Marrella

• North America ( Burgess Shale )
• Asia ( Kaili Formation)

Marrella is an extinct arthropod that was known as Fossil initially of a single layer of mittelkambrischen Burgess Shale ( Burgess Shale ) from British Columbia. Further findings showed that Marella is one of the most common fossils of the Burgess Shale. It is splendens described scientifically only the type species M..

Physique

Marrella was a small animal of up to 2 cm in length. The head shield had two backward long thorns. On the underside of the head were two pair of antennae, a long and flexible, the other short and rigid. The body consisted of 24-26 sections, each with a pair of branched attachments. As with trilobites consisted of the lower part of each annex of a walking leg and the top of a feathery gills leg. At the end of the thorax there was a small, button-like telson, and on the underside of the head were the eyes. The hard, shell-like head was hollow, resembling the shell of a crab. Head and thorns were not mineralized, and it is not clear how these body parts were stiffened. In well-preserved specimens structures were detected, corresponding to an optical lattice. The animals could therefore have provided a colorful shimmering sight.

Ethnicity and lifestyle

Marrella is today expected to an original group that shared a common ancestor with the early arthropods. The animal probably lived as benthic scavengers and fed on the remains of other animals and other organic material.

Along with other unique fossils such Opabinia and Yohoia Marrella shows the diversity of the Burgess Shale.

History of Research

Marrella was the first fossil, the best known of the early editors of the now-famous reference, the geologist Charles Walcott (1850-1927), found in the Burgess Shale. Walcott took Marrella informally as a kind of crab on, and described it formally as a strange trilobite species. Later she was assigned in the Treatise on Invertebrate Paleontology of today discontinued the class Trilobitoidea. 1971 edited Harry Whittington the genus fundamentally new and decided on the basis of training and number of legs, the type of gills and head attachments that the animal neither to the trilobites, the chelicerates still belonged to the Crustacea.