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Wednesday, June 20, 2018

Precambrian Fossil Obama coronatus: Sessile Be De Millions?

     Earth's first complex animals were an eclectic group that lived in the shallow seas between 580-540 million years ago. 




     In great geologic irony, these more complex creatures are now classified as part of the very late Precambian ("Precambrian" means "before life.").




     The iconic Dickinsonia -- large, flat animals with a quilt-like appearance -- were joined by tube-shaped organisms, frond-like organisms that looked more like plants, and several dozen other varieties already characterized by geologists and biologists.




     We can add to that list two new animals discovered by a team of researchers:

     1) Obamus coronatus, a name that honors President Barack Obama's passion for science. This disc-shaped creature was between 0.5-2 centimeters. Obama coronatus is preserved in negative hyporelief and is defined by an overall torus shape produced by a series of arch-shaped spiral grooves. 



      Obamus coronatus (see below, left) was sessile or fixed, embedded to the ocean mat, a thick layer of organic benthic material that covered the early ocean floor. 




     2) Attenborites janeae, named after the English naturalist Sir David Attenborough for his science advocacy and support of paleontology (see above, right.) This tiny ovoid, less than a centimeter across, was adorned with internal grooves and ridges giving it a raisin-like appearance.




     The discovery of Obamus coronatus was published online on June 14, 2018, in the Australian Journal of Earth Sciences, or AJES, and the Attenborites janeae paper is forthcoming in the same journal. The studies were led by Dr. Mary Droser, a professor of paleontology at UC-Riverside.



     Both papers will be included in a 2019 AJES issue focusing on South Australia's Flinders Ranges region, where the discoveries were made.




     Part of the Ediacara biota, the soft-bodied animals are visible as fossils cast in fine-grained sandstone that have been preserved for hundreds of millions of years. These Precambrian lifeforms represent the dawn of animal life and are named after the Ediacara Hills in the Flinders Ranges, the first of several areas in the world where they have been found. Another suite of similar-age fossils was discovered in Sonora, Mexico, in 1995. (an area I worked in and described here).



     In the hierarchical taxonomic classification system, the Ediacara biota are not yet organized into families, and little is known about how they relate to modern animals. About 50 genera have been described, which often have only one species.




     "The two genera that we identified are a new body plan, unlike anything else that has been described," Droser said. "We have been seeing evidence for these animals for quite a long time, but it took us a while to verify that they are animals within their own rights and not part of another animal."

     The animals were seen in a particularly well-preserved fossil bed described in another paper published by Dr. Droser's group that will be included in the Flinders Ranges issue of AJES. The researchers dubbed this fossil bed "Alice's Restaurant Bed," a tribute to the Arlo Guthrie song and its lyric, "You can get anything you want at Alice's Restaurant."




     "I've been working in this region for 30 years, and I've never seen such a beautifully preserved bed with so many high quality and rare specimens, including Obamus and Attenborites," Dr. Droser said. "The AJES issue on the Flinders Ranges will support South Australia's effort to obtain World Heritage Site status for this area, and this new bed demonstrates the importance of protecting it."



You might say Ediacaran preservation is Flinders Keepers (for all).
Steph

34 comments:

  1. So, now we need a latter-day Stephen Jay Gould to write a prequel to Wonderful Life, which, for all its faults, was a Wonderful Book.

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    1. jan, I agree. It is a wonderful book and a prequel is a wonderful idea.

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    1. Blue dunes? Well, this leads to a whole melange of Dune references. In Dune, Spice turns your eyes blue. Too bad Lyot Crater is nowhere near Gale Crater (site of Bradbury Landing). Didn't Crystal Gale sing "Don't It Make My Brown Eyes Blue"?

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  3. This hits close to home. I was working in one of those buildings when Loma Prieta hit in 1991.

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    1. And I should have written 1989. 1991 was the Oakland Wildfire - hard to keep our disasters straight in the land of shake and bake.

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    2. eco, it's scary stuff. Yeah, I recall 1989 as it was the year the Berlin Wall came down, the Loma Prieta earthquakes, and also the year my son was born.

      Sadly, wildfires are raging all over our state now. Although, if it is blatantly human-caused, is that truly a wildfire?

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    3. I hope you aren't recalling those events in order of importance.

      Does "wild" describe the origin or the result? Or an over the top schmaltzy song?

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    4. No, of course not, just reverse chronological order ;-).

      This seems to indicate that conflagrations (https://en.m.wikipedia.org/wiki/Conflagration) are considered wildfires when started by nature. But, nature leaving all that fuel around is a contributory cause, of course. Hard to assign exact percentage blame, though, as in an insurance case.

      Darn you, eco, now I have that schmaltzy song stuck in my head.

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    5. Interesting, other dictionaries only address the process of the fire, not the source. Today everything here has a light dusting of gray ash from a fire near Sacramento.

      And I am chortling with regret that I planted that ear-worm.

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    6. We are hazy here but not too bad on our walk.

      Had a nice chat with my neighbors about politics, travel, and Japanese beetles. The best part? I was able to pass along the "Wildfire" ear-worm to them!

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  4. The Geologists are Coming to the U of Arizona field camp. The beginning of this video is a hoot.

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    1. That link does not work. Try this: https://youtu.be/MEpUjnKV8Ps

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    2. I like the opening rap, but gave up when the voiceover started voicing over what sounded like Tuvan throat singing. (Couldn't decide which was more annoying.)

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    3. Thankfully the throat singing in the beginning was short-lived. (Although I didn’t watch all of it either.)

      That line about most granite really being granodiorite, though. Got right to me. 😂

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  5. Should this story make us feel good? But it does.

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    1. Perhaps not so much “good” as that justice has been served, eh?

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    2. I have to admit, "the circle of life" is the tag line that Wait Wait Don't Tell Me's Peter Sagal attached last month to a story out of Australia wherein Pippa, a little white terrier who spent the last 10 years terrorizing crocodiles at her owner's lodge outside of Darwin, got her comeuppance when she snapped at the head, rather than the tail, of her erstwhile victim. The story has reappeared in subsequent weeks, which makes me wonder whether Sagal has a thing about little white dogs. Don't tell you-know-who....

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    3. Poor Pippa! I won't tell Maizie, for sure.

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    4. Sometimes something you ate disagrees with you.

      For poor Pippa, something she disagreed with ...

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    5. Are you saying the dog gave the croc GRRD?

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    6. For the croc it was a purely refluxive action.

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    7. I think Maizie would appreciate it if we don't bring this up again.

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    8. Yes, gents, please Pippa down about this subject.

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    9. Chow time humor overheard at croc creek:

      What's for breakfast?
      Beagles and Lox.

      Do you like soft cheese on your crackers?
      Briard.

      What's the main course?
      Leonbergers cooked on the Spitz.

      Any spices added?
      Just a Pinscher too.

      What vegetable on the side?
      Collie flower.

      And to drink?
      Maltese.

      What's for dessert?
      Shepherd's pie.

      With cream on top?
      If you want it, Whippet.

      You might think this corny, natives call it Maizie.

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    10. Gee, Daniel Boone never had that much trouble with his raccoon.

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    11. Indeed.

      New Dr. Seuss sequel? The Cat AS a Hat.

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  6. New post on "Spin This News: Parental Chromosomes Develop Apart During Embryo's First Division" is now up.

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