Siphusauctum

Holotype of Siphusauctum gregarium

• Canada ( Burgess Shale )

• Siphusauctum gregarium

Siphusauctum gregarium is an extinct, sessile, pedunculated animal whose fossil remains have been found in Cambrian Burgess Shale in the Canadian Rockies. With a total of 1133 copies Siphusauctum is one of the more common creatures of the Burgess Shale.

The name comes from the Latin Siphusauctum ( " Siphus " means Cup, " AUCTUS " means big) and was awarded because of the shape and size of the animal.

Features

The Siphusauctum gregarium specimens were 1.9 to 22.3 cm high, its shape is described as " tulip-shaped ".

The soft body of the animal consisted of a cup-shaped, bulbous top, a narrow stem and a small, round or pear-shaped holdfast. Calyx and stalk each accounted for about half of the body height. The cup had a flexible, radially symmetrically structured by six segments of shell and was closed at the six small apertures at the bottom and at the top a central anus.

Siphusauctum gregarium was probably an active filter feeders, the food particles that einströmten through the openings at the bottom with the water, covered with comb-like screening devices. It lived in individual- rich colonies on the sea floor. On some Fossil plates individuals have been found up to 65.

Stratigraphy

Siphusauctum was found in the deposit known as the " Tulip Beds" according to this way of life gregarium, which was discovered in 1983 on Mount Stephen, British Columbia. The Tulip Beds in addition Siphusauctum fossils of sponges, Lobopoden, Priapswürmern, arthropods. A well Siphusauctum zuzuordnendes fossil is otherwise known only from a deposit in Utah.

System

Among the extant living organisms have a number of tribes and classes matches Siphusauctum gregarium, such as the cup worms ( Entoprocta ) and sea squirts ( Ascidiae ). Since convincing homologies were not found Siphusauctum is currently not assigned to any tribe and any class.