Siphusauctum

Siphusauctum
	Holotype of Siphusauctum gregarium
Temporal occurrence
	Cambrian
Locations
	Canada ( Burgess Slate );
Systematics
without rank:	Multicellular animals (Metazoa)
without rank:	Tissue animals (Eumetazoa)
without rank:	Bilateria
Trunk :	not determined
Family :	Siphusauctidae
Genre :	Siphusauctum
Scientific name of the family
	Siphusauctidae
	O'Brien , Caron , 2012
Scientific name of the genus
	Siphusauctum
	O'Brien, Caron, 2012
species
	Siphusauctum gregarium; Siphusauctum lloydguntheri;

Siphusauctum gregarium is an extinct, sessile , stalked animal whose fossil remains were found in the Cambrian Burgess Shale in the Canadian Rockies . With a total of 1133 specimens, Siphusauctum is one of the more common creatures of the Burgess slate.

The name Siphusauctum comes from Latin ("Siphus" means cup or mug, "auctus" means large) and was given because of the shape and size of the animal.

features

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

Scheme of the internal anatomy of Siphusauctum gregarium.
A, longitudinal section,
B, cross section through the calyx,
C, longitudinal section through the calyx.
A = anus,
CS = filter comb,
IS & OS = stem,
H = adhesive organ.

The soft body of the animal consisted of a cup-shaped, bulbous upper part, a narrow stem and a small, round or pear-shaped adhesive organ. The calyx and stem each made up about half the height of the body. The chalice had a flexible shell, divided by six segments in a radially symmetrical manner, and was closed except for six small openings on the underside and a central anus on the top.

Siphusauctum gregarium was probably an active filter feeder using comb-like sieve devices to collect food particles that flowed in with the water through the openings on the underside. It lived in colonies rich in individuals on the sea floor. Up to 65 individuals have been found on individual fossil plates.

stratigraphy

Siphusauctum gregarium was found in the deposit known as " tulip beds " after this form of life , which was only discovered in 1983 on Mount Stephen in British Columbia . In addition to Siphusauctum, the Tulip Beds contain fossils of sponges , lobopods , priapus worms and arthropods .

A fossil that can probably be assigned to Siphusauctum is otherwise only known from the " Spence Shale " deposit in Utah . The fossil from the Central Cambrian was assigned to a new species Siphusauctum lloydguntheri in 2017 .

Systematics

Among the most recent living beings, a number of phyla and classes show similarities with Siphusauctum gregarium , e.g. B. the cupworms (Entoprocta) and the sea squirts (Ascidiae). However, since convincing homologies have not been established, Siphusauctum is currently not assigned to any strain or class.

literature

O'Brien LJ, Caron J.-B. (2012): A New Stalked Filter-Feeder from the Middle Cambrian Burgess Shale, British Columbia, Canada. PLoS ONE 7 (1): e29233. doi : 10.1371 / journal.pone.0029233

Web links

Commons : Siphusauctum - collection of images, videos and audio files

University of Toronto: Unusual 'tulip' creature discovered: Lived in the ocean more than 500 million years ago. ScienceDaily, Jan. 18, 2012

Individual evidence

↑ Julien Kimmig, Luke C. Strotz & Bruce S. Lieberman: The stalked filter feeder Siphusauctum lloydguntheri n. Sp. from the middle Cambrian (Series 3, Stage 5) Spence Shale of Utah: its biological affinities and taphonomy . In: Journal of Paleontology . 2017. doi : 10.1017 / jpa.2017.57 .

[kimmig-1] Julien Kimmig, Luke C. Strotz & Bruce S. Lieberman: The stalked filter feeder Siphusauctum lloydguntheri n. Sp. from the middle Cambrian (Series 3, Stage 5) Spence Shale of Utah: its biological affinities and taphonomy . In: Journal of Paleontology . 2017. doi : 10.1017 / jpa.2017.57 .