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Friday, July 5, 2013

Another - Thing - From the Burgess Shale


(Marianne Collins, via University of Toronto, used w/o permission)

"University of Toronto/Royal Ontario Museum scientists discover unusual 'tulip' creature"
Kim Luke, U of T News, University of Toronto (January 18, 2012)
"Lived in the ocean more than 500-million years ago

"A bizarre creature that lived in the ocean more than 500-million years ago has emerged from the famous Middle Cambrian Burgess Shale in the Canadian Rockies.

"Officially named Siphusauctum gregarium, fossils reveal a tulip-shaped creature that is about the length of a dinner knife (approximately 20 centimetres) and has a unique filter feeding system.

"Siphusauctum has a long stem, with a calyx - a bulbous cup-like structure - near the top that encloses an unusual filter feeding system and a gut. The animal is thought to have fed by filtering particles from water actively pumped into its calyx through small holes. The stem ends with a small disc which anchored the animal to the seafloor. Siphusauctum lived in large clusters, as indicated by slabs containing over 65 individual specimens...."

These submerged tulip-animal-things were about as long as a butter knife: 8 inches, 20 centimeters.

If the Lemming's going to discuss Siphusauctum gregarium, those critters need a simpler name. How about siphon-sack? Sounds disgusting, maybe greggies? Siphums?

Siphums it is.

More than 1,100 siphums died in a mudslide somewhere between 505,000,000 and 510,000,000 years back. A half-billion years later, they're related to - nothing we know about.

Like other critters caught in the Burgess Shale, siphums were very well preserved: so scientists have a very good picture of how their innards fit together. They may not have had the colors we see in that picture, or maybe they did.

That article says the siphums are tulip-shaped. To the Lemming they look more like bell peppers, not that it really matters.

More Than You Need to Know About an Extinct Animal

"A New Stalked Filter-Feeder from the Middle Cambrian Burgess Shale, British Columbia, Canada"
Lorna J. O'Brien, Jean-Bernard Caron PLOS ONE (January 18, 2012)


(Lorna J. O'Brien, Jean-Bernard Caron, via PLOS ONE, used w/o permission)
"Figure 14. Schematics of the internal anatomy of Siphusauctum gregarium n. gen. and n. sp.

"A, longitudinal-section of the entire animal, with the major features labeled. B, cross-section of the calyx showing hexaradial symmetry. C, longitudinal-section of the calyx, showing raised comb segments above the level of the anus. Abbreviations: A - Anus, BC - Body Cavity, Con - Conical structure, CS - Comb Segments, ES - External Sheath, H - Holdfast, IC - Inner Conical structure with central tube, IS - Inner Stem, LD - Lower Digestive tract, MD - Middle Digestive tract, OS - Outer Stem, SP - Sheath Protrusion, TG - Transverse Groove, UD - Upper Digestive tract...."

If you still need to know more about Burgess Shale and the critters caught in it, the Lemming recommends www.burgess-shale.rom.on.ca.

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