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.

Vaguely-related posts:

• "Another 17,000,000 Years on the Coelacanth Timeline"
  (April 16, 2012)
• "Eight-Foot Sea Scorpion: Big Claws; Sharp Spines; Weak; Clumsy"
  (January 4, 2011)
• "Ecological Disaster - a Quarter of a Billion Years Ago"
  (December 14, 2010)
• "Cambrian Explosion Evidence: Burgess Shale Fossils aren't Alone"
  (September 12, 2010)
• "Hurdia Victoria: Cambrian Supercritter of the Burgess Shale"
  (March 20, 2009)

Cambrian Explosion Evidence: Burgess Shale Fossils aren't Alone

"Ancient Animal Explosion Gets Bigger With New Finds"
Animal News, Discovery News (September 9, 2010)

"Eight new kinds of the earliest animals from the Cambrian Explosion have been found in a newly explored section of ancient rock in Canada.

"At least eight new kinds of Earth's earliest animals from the mysterious and controversial Cambrian Explosion have been discovered in a unexpected section of ancient rock 30 miles from the famous Burgess Shale of Canada. The discovery suggests such old, rare fossils are more common than previously thought.

"Like the fossils of the original Burgess Shale, the new discoveries are remarkable because they preserve features of animals which had only soft parts -- like gills and eyes -- and remained intact for more than half a billion years.

"That's a time when animals evolved from being very small, simple organisms into a wildly creative, explosive variety of sometimes bizarre creatures. These were culled by natural selection over time, leaving the more familiar main animal groups we see today.

"Among the more dramatic discoveries is a new kind of 'anomalocaridid' -- the monster shrimp-like top predator a half-billion years ago. Some of these sorts of beasts have been found up to two meters long in shale from Chengjiang, China...."

We've known about the Burgess Shale fossils for a long time - but it looked like that treasure-trove of detailed soft-bodied fossils was a fluke. The Burgess Shale formation happened when fine silt fell off an underwater cliff, burying critters swept up in the avalanche.

The new find is from shale that formed from fine mud that was on a gently sloping surface - and preserved tracks of the buried critters. That strongly suggests that the creatures lived near where they were found. And that the sequence of events needed to preserve the fossils isn't as rare as we thought.

Besides the new Canadian discovery, similar fossils have been found in China, Greenland and Australia.

Looks like paleontologists will have a great deal more data to work with.

Related posts:

• "Two Thirds of a Billion Years Ago: Earth's First Animals?"
  (August 18, 2010)
• "Four Legs, a Tail, and Tracks a Third of a Billion Years Old"
  (July 26, 2010)
• "Clockwork Mass Extinctions, Cosmic Rays, and Cycles"
  (July 14, 2010)
• "Lemming Tracks: Observations by an Opportunistic Omnivore"
  (April 20, 2010)
• "Animals That Don't Need Oxygen - It Gets Weirder"
  (April 9, 2010)

Hurdia Victoria: Cambrian Supercritter of the Burgess Shale

"Ancient Creature Was a Miniature Monster"
LiveScience (March 19, 2009)

"A fossil from famous shale deposits in Canada was thought to be unremarkable, but a new study finds that it's actually the remains of a 500-million-year-old monster-looking predator.

"The Burgess Shale (a UNESCO World Heritage Site in the Canadian Rockies of British Columbia) has yielded exceptionally well-preserved fossils that present a remarkable snapshot of Cambrian marine life from 505 million years ago.

"The first fragments of the monster fossil (a species called Hurdia victoria) were described nearly 100 years ago, and at the time, they were thought to be part of a crustacean-like animal, and other parts were subsequently described as multiple organisms including jellyfish, sea cucumbers and other arthropods...."

Calling this critter "miniature" is all in your point of view. It was about a foot and a half long, which is very roughly the size of a cat. Today, not all that big. Half a billion years ago, there weren't too many things around bigger than that. That we know of.

Mistaking Parts for Other Critters - How Stupid is That?

Not very, actually. When creatures die, the parts don't all stay connected. And, when you're looking at a creature that's not much like anything around today, it's nowhere near as easy as "The toe bone's connected to the foot bone...."

Burgess Shale: A Century of Weirdness

Over a half-billion years ago, what's now Canada's Yoho National Park in the Rocky Mountains was under water, near the equator. The Rocky Mountains wouldn't be there for a very long time, but there was a limestone cliff with a nearly-vertical drop of 100 meters (around 300 feet). Fine mud flowed, and fell, off the top of the cliff, washing whatever creatures were in or near it along. The mud and creatures piled up at the base of the cliff.

That mud got buried under more debris, and turned to shale. Continents moved, collided, and moved again. Somewhat later, what had been a shallow sea floor was about two miles above the current sea level.

Around that time, Charles D. Walcott became Secretary of the Smithsonian Institution and found fossils in the shale.

Lots of fossils.

Walcott noticed the ancient animals in 1909. By now, there are about 65,000 in the Smithsonian National Museum of Natural History collection.

The Burgess Shale deposits are particularly valuable because the fine mud preserved very small details in the creatures buried there. And, since what put the mud and the animals there happened very quickly, paleontologists get to study a fairly complete selection of creatures that lived in one place at one time - a sort of ecological snapshot.

Fine Mud, Rare Event

And, as the Smithsonian Museum wrote, "The hard parts of all these animals caught in the mudslide were preserved as fossils, like the process at any other Cambrian site. However, here the fine mud also penetrated and filled all available spaces within the animals, thus preserving the shapes and locations of all the soft parts. This is a rare event and has made these fossils extremely valuable to the paleontologist."

That was the good news. The even-better news was that quite a few of the specimens were not just strange: they were downright weird. There were animals that didn't seem related to any creatures alive today.

Back to Hurdia victoria, the critter to in that picture to the left. The front part of the animal, on the right, has an over-size, three-part carapace out in front of it's head. What it's there for is anyone's guess at this point.

Which is what makes Hurdia victoria and the other Burgess Shale creatures so fascinating.

There's a lot that we don't know about them. Yet.

Some of the organisms seem to be ancestors of forms of life we are familiar with: algae, chordates (animals with notochord or spinal column - like us) and arthropods (animals with jointed limbs, a segmented body and an exoskeleton made of chitin - like spiders). Others are sort of like forms of life we're familiar with: but don't seem related to anything we've seen before.

There are creatures from familiar phyla:

• Porifera (sponges)
• Annelida (segmented worms)
• Priapulida (cactus worms)
• Onychophora (velvet worms)
• Arthropoda (insects, crustaceans, and the like)
• Echinodermata (sea urchins, starfish)
• Chordata (fish, birds, us)

Okay: some of those aren't that familiar to most people. But, they're kinds of critters that scientists have run into before.

Then, there's "Unknown Phyla" - creatures that existed, but don't have any (known) living counterparts. Some of them aren't like anything that's been found since the Cambrian period.

Like opabinia regalis, there. Five eyes, a long and flexible proboscis with grasping spines at the end, and rows of lobes that probably helped it swim: this isn't quite like anything that's alive today.

Scientists thought their colleague's reconstruction of the creature was a pretty good joke when they first saw it, at a meeting back in 1972. Then, they found out that the presenter was

1. Serious
2. Right

That five-eyed whatsit is a pretty good example of what we've got in the Burgess Shale: a huge amount of detailed evidence, most of which we still don't understand.

A century after Walcott noticed that first fossil in the Burgess Shale, paleontologists are still putting the puzzle together. Literally, in the case of Hurdia victoria.

There's exciting work still to be done. And, for people like me, the prospect of watching as paleontologists learn more about how life has developed.

Slightly related posts:

• "Faith and Reason, Religion and Science"
  A Catholic Citizen in America (March 20, 2009)
• "Catholic Church, Creationism, Evolution, Facts and Faith"
  A Catholic Citizen in America (March 5, 2009)

More:

• "Prehistoric puzzle reveals fearsome predator"
  Cordis News (March 20, 2009)
• "The nature and significance of the appendages of Opabinia from the Middle Cambrian Burgess Shale"
  Lethaia, via Wiley interScience (April 8, 2007)
• "Fossils of the Burgess Shale - Middle Cambrian"
  Georgia Perimeter College Faculty and Staff (November 12, 1996)
• "The Burgess Shale Geoscience Foundation"
• "Burgess Shale fossils"
  Department of Geoscience, University of Calgary
• "Localities of the Cambrian:
  The Burgess Shale"
  UCMP Berkeley
• "The Burgess Shale : A Hidden Treasure In The Canadian Rockies"
  Dr. Ken Hooper Virtual Natural History Museum, Ottawa-Carleton Geoscience Centre
• "The Burgess Shale"
  Smithsonian Institution