Improbability of Similar Cambrian Fossils in China and Canada


Occasionally I put in my 2 cents worth on other blogs.  After getting tired of an unrepentant creationist who copies and pastes Walt Brown’s blatant lies, I answered 3 paragraphs of a much longer screed.  I see now why anyone with any sense avoids debating these idiots.  It takes far longer to answer their assertions than it does for them to come up with them, and by then, they’ve moved on.  I’ll start by quoting the offending material.

One of the major unsolved problems of geology and evolution is the occurrence of diversified, multicellular marine invertebrates in Lower Cambrian rocks on all the continents and their absence in rocks of greater age.” Daniel I. Axelrod, “Early Cambrian Marine Fauna,” Science, Vol. 128, 4 July 1958, p. 7

….

Granted an evolutionary origin of the main groups of animals, and not an act of special creation, the absence of any record whatsoever of a single member of any of the phyla in the Pre-Cambrian rocks remains as inexplicable on orthodox grounds as it was to Darwin.” T. Neville George (Professor of Geology at the University of Glasgow), “Fossils in Evolutionary Perspective,”  Science Progress, Vol. 48, No. 189, January 1960, p. 5.

Evolving so many unusual animals during a geologic period is mind-boggling. But doing it twice in widely separated locations stretches credulity to the breaking point. According to the theory of plate tectonics, China and Canada were even farther apart during the Cambrian.

Yes. I’m incredulous! When will you guys learn some basic geology? Let’s take it from the top, and talk about continents and movement of cratons.

2.7 Gya — Neo-Archean era — The Kenorland supercontinent forms by accretion and serial aggregation. This is about the same time as the Slave and Superior cratons (in Canada) began to accrete.

2.6 Gya — Neo-Archean era — Two parts of China became part of Kenorland’s accretion undergoing orogeny for the next 100 to 200 million years.

2.5 Gya — Neo-Archean era — The Arctica continent was formed, containing the Laurentian Shield and Siberian craton. The Laurentian (Canadian) Shield was formed from the Slave and Superior cratons. It underlies today’s North American craton.

2.45 Gya — Aphebian/Siderian period at the beginning of the Paleo-Proterozoic era — Arctica collided with the Kenorland supercontinent.

2.1 Gya — Rhyacian period of the Paleo-Proterozoic era — Kenorland broke into several smaller continents, with the Arctican craton becoming part of the Nena continent along with Baltica and Antarctica. This is also the time that the first known eukaryotes formed (Francevillian B Formation in Gabon).

2.0 Gya — Orosinian period of the Paleo-Proterozoic era — This is the period of accretions of the cratons of eastern South America and West Africa to form the continent Atlantica.

Although the term “acritarch” technically refers to non-carbonate, non-siliceous organic fossils and appeared as early as 3.2 Gya, it is often used in the sense of being a eukaryote, often appearing as resting cysts of chlorophytes, the ancestors of dinoflagellates, or as egg cases of metazoans. 2.0 Gya marks the beginning of eukaryotic acritarchs. In Oklo, Gabon, uranium-precipitating bacteria began producing the world’s first nuclear reactor, which went critical about 1.7 Gya.

1.8 Gya — Statherian period at the end of the Paleo-Protozoic era — Accretions beginning during the breakup of Kenorland were complete by 1.8 Gya, forming the new supercontinent, Columbia, which contained Laurentia and Baltica (the former continent, Nena), Ukrainian Shield, Amazonia, Australia, and possibly Siberia, North China, and Kalaharia.

1.6 Gya — Riphean/Calymmian period at the beginning of the Meso-Proterozoic era — Columbia began fragmenting with rifting of western Laurentia, eastern India, southern Baltica, southeastern Siberia, northwestern South Africa (Kalahari Copper Belt), and the northern margin of the North China Block.

1.5 Gya — Riphean/Calymmian period at the beginning of the Meso-Proterozoic era — Laurentia became an independent continent (with rifting starting about 1.6 Gya). This corresponded with widespread anorogenic magmatic activity in North America, Baltica, Amazonia, and North China. This also marks the beginning of structurally complex eukaryotes.

1.2 Gya — Stenian period at the end of the Meso-Proterozoic era — God invented sexual reproduction in the form of the red alga Bangiomorpha pubescens (couldn’t have chosen a more appropriate name).

1.1 Gya — Stenian period at the end of the Meso-Proterozoic era — The Rodinia supercontinent formed from the fragments of Columbia and contained most of the landmass on earth (including Laurentia and both Chinas). This also marks the beginning of the dinoflagellates.

1.0 Gya — Tonian period at the beginning of the Neo-Proterozoic era — Vaucherian algae make their appearance along with trace fossils of simple multi-celled eukaryotes, and the first radiation of dinoflagellate-like acritarchs occurs.

.85 Gya — Cryogenian period of the Neo-Proterozoic era — This marks the start of a stretch of glaciations in which the earth froze over several times, called the snowball or slushball earth. Originally, only the Varangian glaciation was recognized as occurring from .80 to .63 Gya. This has now been split into two more events: the Sturtian and Marinoan glaciations. There are problems with dating these events, as they are marked by glacial deposits and striations, isotope ratios, and cap carbonates, which differ from continent to continent, and depending on the publication date of the source, the dates and occurrences of these 3 glaciations can vary significantly. In some locations (e.g. South Australia), there is evidence of only 2 glaciations, and in others, as many as 6 (Britain and Ireland). To add to the confusion, different names may be applied to the similar events.

The following glaciation dates and names are merged from Kent Condie’s Earth as an Evolving Planetary System (2004) and Wikipedia. Kaigas: .778 to .735 Gya. Sturtian: .72 to .70 Gya (possibly a second more severe pulse beginning with Kaigas?). Marinoan: .660 to .635 Gya. Gaskiers: .583 to .582 Gya (although severe, very unlikely to have been global).

This is also the beginning of the rift of continental masses of Australia, eastern Antarctica, India and the Congo and Kalahari cratons from the rest of Rodinia. A map is shown below.

Image

.75 Gya — Cryogenian period of the Neo-Proterozoic era — Laurentia separated from Rodinia as a part of the Protolaurasian continent and was in danger of rifting itself. It marks the accelerated breakup of Rodinia and the beginning of the Sturtian glaciation.

The first protozoan (animal ancestors) fossils appear. Testate amoebae from .742 Gya were found in the Chuar Formation of the Grand Canyon.

.70 Gya — Cryogenian period of the Neo-Proterozoic era —The first worm impressions appeared in China.

>.635 Gya — Cryogenian period of the Neo-Proterozoic era — Biomarkers (steranes, free and kerogen-bound) show the presence of demosponges before the end of the Marinoan glaciation. Fossil sponges are found as early as .575 Gya. An animal fossil (most likely a sponge) in the Trezona Formation was dated between .70 and .66 Gya.

.630 Gya — Ediacaran/Vendian period at the end of the Neo-Proterozoic era — Many sources mark the start as 635 Gya, corresponding to the end of Marinoan glaciation. The older Vendian designation begins at 650 Gya. The atmosphere was 8% oxygen (only 40% of current level) and 4500 ppm carbon dioxide (1600% of pre-industrial level).

.60 Gya — Ediacaran/Vendian period at the end of the Neo-Proterozoic era — The short-lived supercontinent of Pannotia formed when Proto-Laurasia and Proto-Gwondana rotated into the Congo craton.

.575 Gya — Ediacaran/Vendian period at the end of the Neo-Proterozoic era — The Ediacaran radiation of animals began in earnest.

.56 Gya — Ediacaran/Vendian period at the end of the Neo-Proterozoic era — Trace fossils (e.g., worm burrows) and small bilaterally symmetrical animals appeared along with the earliest arthropods and fungi.

.555 Gya — Ediacaran/Vendian period at the end of the Neo-Proterozoic era — Kimbrella, suspected to be an early mollusc, arrived.

.55 Gya — Ediacaran/Vendian period at the end of the Neo-Proterozoic era — Possible early comb-jellies, sponges, corals, and anemones appeared.

Image

.544 Gya — Ediacaran/Vendian period at the end of the Neo-Proterozoic era — This marks the arrival of SSFs (Small Shelly Fauna). Some of the fossils represent the entire skeletons of small organisms, including the mysterious Cloudina and some snail-like molluscs. However, the bulk of the fossils are fragments or disarticulated remains of larger organisms, including sponges, molluscs, slug-like halkieriids, brachiopods, echinoderms, and onychophoran-like organisms that may have been close to the ancestors of arthropods.

.542 Gya — Cambrian period at the start of the Paleozoic era in the Phanerozoic eon — This marks the first worldwide appearance of the trace fossil Treptichnus pedum, used to mark the start of the Cambrian.

There is a possible Ediacaran extinction event marked by a carbon excursion  that exactly matches the boundary date for the Cambrian, along with an abrupt change in fauna. The atmosphere was 12.5% oxygen (63% of current level) and 4500 ppm carbon dioxide (1600% of pre-industrial level).

Pannotia disintegrated into four continents: Laurentia, Baltica, Siberia and Gondwana.

.53 Gya — Cambrian period at the start of the Paleozoic era in the Phanerozoic eon — There are trace fossils of the first land animals — possibly related to the later Cambrian Euthycarcinoids, aglaspidids or eurypterids.

.526 Gya — Cambrian period at the start of the Paleozoic era in the Phanerozoic eon — Trilobytes appear.

.525 Gya — Cambrian period at the start of the Paleozoic era in the Phanerozoic eon — Graptolytes show up. In the map below, notice how small North and South China are, being mostly under water.

Image

.51 Gya — Cambrian period at the start of the Paleozoic era in the Phanerozoic eon — Cephalopods and chitons arrive.

.505 Gya — Cambrian period at the start of the Paleozoic era in the Phanerozoic eon — Burgess Shale was fossilized.

I have traced Laurentia (Canada) and the two Chinas (North and South) from their origins in the Archean era. Note that in Rodinia, they were part of the same continental structure. In Pannotia, they were separated by the Iapetus Ocean with nearly contiguous continental shelves. Even in the late Cambrian, there would have been no problem for plankton, nekton, pelagic, and benthic animals forming a swath between Laurentia and the two Chinas. (Note that it as far between North and South China as it is for either with respect to Laurentia.

That leaves the littoral animals, and you didn’t bother telling us which animals it is so unbelievable to find with this distribution. Littoral animals often have a larval stage during which travel is not a problem. Even for the more sedentary, connecting continental shelves and those with short distances between them form a chain that crosses the Iapetus. Exactly which animals couldn’t you imagine having made the voyage? Why do you think that Laurentia and the two Chinas were farther separated than Canada and China are today (especially by deep water)?

And how was it that you found an “occurrence of diversified, multicellular marine invertebrates in Lower Cambrian rocks on all the continents and their absence in rocks of greater age“? You haven’t read any of the paleontology of the last 50 years? Is there something wrong with the [Precambrian] timeline I’ve shown here?

And you’re claiming “the absence of any record whatsoever of a single member of any of the phyla in the Pre-Cambrian rocks remains as inexplicable on orthodox grounds as it was to Darwin“? Again, where have you been the last 50 years? Are the red entries in my timeline somehow not obvious enough?

Everything I’ve presented here came from online literature searches that were also available to you, had you bothered. You are so damned lazy, you can’t be bothered to check anything Walt Brown says.

Brown doesn’t bother with explanations of anything. He probably thinks that news is only a series of sound bites. Many (if not most) creationists use quote mining, in which they leave out part of a quote, changing it’s meaning, or they change it slightly, altering its meaning, or they misattribute the quote, or they invent one. So far, I haven’t caught Walt doing that, mostly because I don’t have access to his sources.

What he does, however is nearly as bad. He picks a source that predates whatever he wants to discuss, and then chortles at how stupid these scientists were for not having foreseen the future discoveries that would show that they were wrong. Look at the dates on the two articles I quoted at the beginning of this rant. Walt does it constantly, and I have nearly broken down and written to show what he has done. Before this, I started to answer his crap about angiosperms.

In the original, I continued in this vein, but it’s irrelevant here.

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