Cloudinids and a Big Fish: Learning More of Earth's Story

It looks like cloudinids, critters whose skeletons look like a stack of ice cream cones, made Earth's first reefs.

They've been extinct for a long time, and so has an unexpectedly big Silurian fish. I'm fascinated by this sort of thing, your experience may vary.

1. Cloudinids and a Precambrian Reef
   • Critters, Catastrophes, and a Changing World
2. Silly Putty and Science
3. Big Fish in the Silurian Sea
   • Extinction Events, Large and Small

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Thinking about God's Design Decisions

Every time I write one of these 'science' posts, I wonder if I need to explain why thinking is not a sin. If you've been here before, feel free to skip down to 'Cloudinids and a Precambrian Reef.'

As a Catholic, I'm obliged to believe that God creates everything, including us. We're designed with a thirst for truth, which should lead us to God. Thinking about the world's beauty and order doesn't get in the way of faith. (Catechism of the Catholic Church, 27, 31-35)

God's design decisions don't upset me. I like living in an immense universe: one where we keep finding new facets of reality. It's as if God created a world loaded with puzzle games for us to solve.

But since so many folks seem convinced that science and religion are at war, an explanation may be in order. Or, not. I'll let you decide.

Accepting Reality

Until about four centuries ago, an educated Englishman could reasonably think that the universe was a tidy little affair, about six thousand years old and no more than several thousand miles across.

The scale of this imagined universe was, in a way, comfortable: large enough make the extravagant language of Psalms 19:2 and Habakkuk 3:6 seem pleasantly grand, without being too overwhelming.

Meanwhile, natural philosophy had become science. By the time Ussher published his famous chronology, folks like Galileo and Copernicus had been following up on speculation that Earth wasn't the only world. (December 13, 2013)

A century after Ussher, geologists like Georges-Louis Leclerc realized that Earth had to be a great deal older than a half-dozen millennia. Some folks in the 18th century didn't like those newfangled ideas. (May 23, 2014; September 27, 2013)

Others, including scientists, were willing to take creation 'as is,' and kept learning. The reality we live in is awesome: vast, and so ancient that all recorded history is like a few moments in comparison.


(From Efbrazil, via Wikimedia Commons, used w/o permission.)
(This universe, so far: 13,800,000,000 years mapped onto a 12-month calendar.)

Seeking Truth

Around the middle of the 19th century, a quaint notion popped up. Some 'serious thinkers' said that since the universe is huge, ancient, and operates under rational, knowable, physical laws: an eternal and rational God cannot exist.

I think that's a silly idea, but quite a few folks who want God to go away insist that it's so. More remarkably, some Christians agree with them.

I don't mind living in an almost-unimaginably enormous and ancient universe.

Even if I did, it wouldn't make much difference. God's God, I'm not, and I figure that my part of my job is appreciating this wonder-filled creation — not telling God how it should be designed.

As for getting upset that change happens, I'm a Catholic. We're told that change is a part of this creation. The universe is in a "state of journeying" toward perfection. We're not there yet, obviously. (Catechism of the Catholic Church, 302)

Faith and science are, or should be, concerned with truth. Honest research cannot threaten informed faith, because both involve what God has created.

"...God cannot deny himself, nor can truth ever contradict truth. ... methodical research in all branches of knowledge, provided it is carried out in a truly scientific manner and does not override moral laws, can never conflict with the faith, because the things of the world and the things of faith derive from the same God...."
(Catechism, 159)

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1. Cloudinids and a Precambrian Reef

(From Reuters, used w/o permission.)
("Reefs built by Cloudina 548 million years ago are pictured in the Nama Group in Namibia in this undated handout photo...."
(Reuters))

"Reef madness: scientists find oldest animal-built marine structure"
Will Dunham, Reuters (June 26, 2014)

"A sea creature that looked like a stack of tiny ice cream cones is providing quite a treat for scientists studying the dawn of animal life on Earth.

"Researchers said on Thursday they found fossils of the oldest-known animal-made reef in Namibia, built by a small, filter-feeding seabed creature called Cloudina 548 million years ago.

"The discovery indicates that important evolutionary developments were unfolding millions of years before the so-called Cambrian explosion when many of the major animal groups first appeared. It also showed that reef building by marine invertebrates, akin to today's coral reefs, began 18 million years earlier than previously known.

"Cloudina, one of Earth's earliest-known animals, was the first one with a hard skeleton, in this case an outer shell.

"Its fossils have been found in Europe, North and South America, Asia and Africa but it had not been known that it built reefs - a collective activity that helps gain protection from predators and improves food gathering...."

Cloudinids are extinct, and have been for more than a half-billion years. Scientists don't know exactly what they looked like, since we've only found their skeletons. There's a chance that paleontologists will find a Precambrian equivalent of the Burgess Shale Formation, but for now — all that's left are those nested cones.

There isn't anything particularly cloud-like about Cloudinids, by the way. They're named after Preston Cloud, a paleontologist who died in 1991.

Cloudinids weren't particularly big by today's standards: 0.3 to six-and-a-half to eight millimeters across by 8 millimeters to 15 centimeters long.

The nested cones were almost certainly open at the bottom. We can't be sure, but when the animal was alive it could probably bend: and would have looked like a worm. Sort of. Probably. Actually, since no soft tissue has been found yet, we don't know for sure.

Cloudinids may be related to cnidarians like sea anemones, corals, and jellyfish; annelid worms; or something else. They're not quite like anything that's alive today.

Despite what the Reuters article says, I gather that cloudinids weren't the first to grow a shell. They were among the earliest animals with shells, though, and the most common Precambrian shelled animals.

Biomeralized skeletons like the cloudinids' shells — support structures built from minerals, not organic material — are 'cheaper' than all-organic skeletons like an insect's shell, and that's another topic. ("Biomineralization," Wikipedia)

More than you probably want to know about Cloudina:

• "Skeletogenesis and asexual reproduction in the earliest biomineralizing animal Cloudina"
  Hong Hua, Zhe Chen, Xunlai Yuan, Luyi Zhang, Shuhai Xiao; abstract, GeoScienceWorld (April 2005)

Critters, Catastrophes, and a Changing World

(From Ron Blakey, NAU Geology, via Wikimedia Commons, used w/o permission.)
(Earth in the Late Ediacaran period, about 560,000,000 years ago.)

Cloudinas were facing catastrophic environmental changes in the Ediacaran, 635,000,000 to 542000,000 years back.

Earth was warming at an alarming rate: it was the end of a comparatively stable era of world-wide glaciation. The last I heard, scientists aren't sure whether or not there was ice-free ocean near Earth's equator at the height of the Cryogenian period.

Cloudinas and quite a few other critters didn't survive when Earth thawed out: but many of those that did became larger, more complex; and much more diverse. Most of today's basic types of animals started in the Cambrian explosion; some that aren't part of today's mix, like Vetulicolia, Opabinia, and Archaeocyatha.

I'm not upset that we live in a changing universe: and it wouldn't make much difference if I was. (November 29, 2013; August 30, 2013; January 18, 2012)

Silly Putty and household scrub brushes are important tools for paleontologists, and that's my next topic. One more thing, though, about Cloudinas and catastrophes:

• Extinction of Cloudina and Namacalathus at the Precambrian-Cambrian boundary in Oman"
  Joachim E. Amthor, John P. Grotzinger, Stefan Schröder, Samuel A. Bowring, Jahandar Ramezani, Mark W. Martin, Albert Matter; abstract, Geology (February 4, 2003)

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2. Silly Putty and Science

(From Emily Hughes, via Explorers Journal, National Geographic; used w/o permission.)
("Here is Silly Putty at its finest: displaying the grooves and curves of an ancient marine fossil."
(Emily Hughes))

"The Importance of Silly Putty in Paleontology"
Emily Hughes, Explorers Journal, National Geographic (June 24, 2014)

"Emily Hughes brings us tales of adventure and discovery from the Australian Outback as she and her mother search for unbelievably ancient fossils. Here, she describes the tools of the trade.

"Silly putty: it bounces, it stretches, and it's perfect for making molds of ancient fossils. That, along with other useful tools such as scrub brushes like the ones in your kitchen, dental picks (as in what the dentist uses to scrape the plaque off of your teeth), and good-old-fashioned H₂O are the major paleontological tools we need when we are out in the field.

"You might be wondering why we don't use fancier high-tech equipment. Well, it turns out everything we need to map our Australian rocks and fossils is available to us in most stores (minus the dental tools). We use these because they work really well, they're easy to find, and it's fun to see the clerk’s face when we check out in a store with 20 scrub brushes and 10 pounds of Silly Putty...."

Somebody invented Silly Putty in the 1940s. Crayola says James Wright invented it, and they may be right. As a substitute for rubber it was a dismal failure.

As a child, I thought Silly Putty was wonderful stuff: and I still do. I didn't use it to make high-resolution imprints of fossils, of course: I had fun watching it flow, made mirror-image prints of pictures in newspapers, and that's yet another topic.

Emily Hughes points out that Silly Putty's fine texture and liquid-like properties make it a good choice for making high-resolution imprints. My guess is that for permanent imprints, she uses wax, plastic, or other stuff: and a lot of time.

I'd like to see the reaction they got to picking up 20 scrub brushes and 10 pounds of Silly Putty: and that's yet again another topic.

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3. Big Fish in the Silurian Sea

(From Brian Choo, via Sci-News, used w/o permission.)
("Megamastax amblyodus consuming the galeaspid Dunyu longiforus."
(Sci-News))

"Megamastax amblyodus: Largest Silurian Vertebrate Discovered in China"
Sci-News(June 13, 2014)

"Megamastax amblyodus was a primitive lobe-finned fish (Sarcopterygii). The paleontologists think it measured up to 1 m in length and had 17 cm long jaws.

" 'It's always been thought that Silurian fish were all small because, until now, no fossils of species more than 30 cm or so in length have ever been discovered. But from the site in Yunnan, near the city of Qujing, we uncovered a diverse collection of jawed fish from Silurian sediments, including the new Megamastax, a predator vastly larger than any other vertebrate known from this age,” explained Dr Choo, who, along with colleagues, reported the discovery in the journal Scientific Reports.

"Three fossil specimens of this prehistoric fish were unearthed from the Silurian Kuanti Formation (about 423 million years ago) of Yunnan, China.

"Vastly larger" in this case still isn't all that big, by today's standards. Megamastax was about three times as long as the previous Silurian record-holder.

Since today's bigger fish tend to be more sensitive to how much oxygen is in their water, the lack of big(ish) Silurian fish had been used to estimate how much oxygen was in Earth's atmosphere at the time.

Megamastax either didn't need as much oxygen for its size as one of today's fish, or there was more oxygen around than scientists thought, or something else is going on. It's a familiar situation: when we learn something new, we learn that there's more to learn.

Extinction Events, Large and Small

(From Ron Blakey, NAU Geology, via Wikimedia Commons, used w/o permission.)
(Earth in the Silurian, 430,000,000 years ago.)

Discovering Megamastax amblyodus also means that big predatory fish were around earlier than we'd thought. Up to now, big fishy predators weren't known before the Devonian: 419,200,000 to 358,900,000 years ago, give or take a few million.

Earth was a bit warmer during the Silurian than it is today: and a whole lot warmer than it was during the Ordovician.

What with a warm climate, lots of shallow seas, and not much in the way of mountains, the Silurian sounds like advertising for a Caribbean cruise — except that oxygen levels were almost certainly lower than we'd like, and moss forests were popping up near lakes and streams.

The Silurian ran from 443,400,000 to 419,200,000 years ago: again, give or take a few million. Those 24 million years weren't all beer and skittles. At least three small extinction events punctuated that period of Earth's history.

They weren't much, though, compared to the Ordovician-Silurian extinction events, two mass extinctions separated by about a million years that mark the start of the Silurian. Almost two thirds of life on Earth died then. Taken together, those two are the second-biggest extinction event we know of, after the big one one at the end of the Permian.

The Ordovician-Silurian extinction events weren't all bad news, from our point of view. It wasn't until after those massive die-offs that some critters left the ocean and started living on land: and that's still more topics.

More about Megamastax amblyodus:

• "The largest Silurian vertebrate and its palaeoecological implications"
  Brian Choo, Min Zhu, Wenjin Zhao, Liaotao Jia, You'an Zhu; abstract, Scientific Reports (received January10, 2014; accepted May23, 2014; published June 12, 2014)

Related posts:

• A changing universe
  
  • "Lukewarm Dinosaurs, the Earliest Known Fish, and Durable Faces"
    (June 20, 2014)
  • "Truth, Toothpicks, Beaks, and God"
    (December 13, 2013)
  • "Scorpions, Acid Rain, and the Great Dying"
    (November 29, 2013)
  • "Oxygen, Ice, and Our Changing Earth"
    (August 30, 2013)
  • " 'In a State of Journeying' "
    (January 18, 2012)
• Faith and reason
  
  • "Science, Faith, and Albertus Magnus"
    (February 23, 2014)
  • "Personal Preference, Reality, and Dealing with Knowledge"
    (January 2, 2014)
  • "Truth Cannot Contradict Truth"
    (October 13, 2013)
  • "Love, Technology, and Being Human"
    (October 6, 2013)
  • "Beetles, Bibles, and Brains"
    (September 21, 2013)