‘O Oysters, come and walk with us!

Dr. John Morris, president of the Institute for Creation Research, just can’t seem to stop himself from saying ignorant things. And saying them about things for which there is no reason to be ignorant about even for a young earth creationist.

In the October issue of Acts & Facts, in yet another of a seemingly endless  parade of snarks about the Cambrian radiation (Morris 2008a) he throws out this little nugget about the famous mid-Cambrian Burgess Shale fossil locality:

Morris: In 1940, fossils of amazing clarity and diversity were found in Canada’s Burgess Shale. The extremely fine-grained shale preserved intricate details of previously unknown invertebrates.

The problem is the Burgess Shale was discovered by Charles Walcott in 1909 and quarried for fossils for decades before 1940. And as far as I know nothing significant regarding the Burgess Shale happened in 1940 either. But why get this wrong? Never mind bothering to crack a book on the subject, if Morris had bothered to Google the Burgess Shale the very first thing to pop up would have been the Wikipedia entry on the fossil locality which in a matter of seconds would have given him the correct date for its discovery.

It’s like he’s not even pretending to care about getting even the most basic and noncontroversial facts straight.

Then out of all the strange and unusual fossil critters from the Cambrian he could have talked about he chose, purposefully I believe, to focus on clams (bivalve mollusks). Why bivalves? Probably because they are group that at least superficially and in the eyes of non-specialists, has not changed all that much through geologic time.

Morris: Let’s suppose you want to find the forefathers of the clams, a prominent resident of the Cambrian Explosion, for instance. As you follow the fossil clues into ever “older” strata, what do you find? You find clams. The first or lowest occurrence of clams is abrupt or sudden.

The first two sentences above are a bit confusing. Does he mean by asking us to “follow the fossil clues into ever older strata”, to look into strata older than the Cambrian? If so, then he is mistaken because there have not been any bivalve mollusks found in Precambrian strata.

If he simply means we should “follow the fossil clues” back to the Cambrian then he is only greatly misrepresenting the facts by referring to “clams” as being a “prominent resident” among Cambrian fauna.

The classic “prominent resident” of the Cambrian was the trilobite (Phylum Arthropoda, Class Trilobita) with over 1500 genera being represented in the period. Another well represented group was the Archaeocyathans, an extinct type of sponge (Phylum Porifera) known only from the Cambrian which was made up of about 300 genera (in two Classes, Regulares and Irregulares). Here is a partial listing (ones I could readily find numbers on) of some other Classes (grouped by Phylum minus the groups listed above) with significant Cambrian representation:



  • Orthothecimorpha: 57 genera
  • Hyolithomorpha: 66 genera




[Note: Most of the numbers on genera here are compiled from data given on Sepkoski’s Online Genus Database.]

In comparison bivalve mollusks from the early to mid-Cambrian are only represented by 2 solidly identified (tiny 1-5mm) genera: Pojetaia & Fordilla, with perhaps two or three other possible genera (still under debate), so for Morris to speak of them as being prominent residents of the Cambrian is misleading to say the least.


There is a 10 million year gap in the bivalve fossil record, from the mid-Cambrian to the early Ordovician, during which no bivalve fossils are known. Then at the beginning Ordovician bivalve mollusks reappeared in much greater diversity ballooning up to a peak of around 80 genera only to crash at the end of the period when 70% became extinct (Fang 2006, p.316). After a few ups and downs, there are living today over 1200 genera of bivalve mollusks (Valentine et al. 2006).

Morris: There are no ancestors that are not clams. An evolutionary lineage is impossible to discern, for clams have always been clams.

“Clams” is not a scientific term but a popular term for any number of the taxonomic Class of mollusks: Bivalvia (=Pelecypoda). “Clams have always been clams” is something like saying mammals (Class mammalia) have always been mammals (which Dr. Morris might claim as well). The point is that within both these Classes there has been a pattern to the fossil record with different Orders, Families, Genera and Species appearing and disappearing for which Dr. Morris and other advocates of young earth creationism (and its associated idea of Flood geology) have no rational explanation.

Morris: Fossil clams are quite abundant, found all over the world in rocks of every age, and clams live today. Great variety among them abounds, but they are still clams. Variety does not speak to ancestry.

But bivalve mollusks of today are not the same as those found in the Mesozoic, and those in the Mesozoic are not the same as those found in the Paleozoic. Different species come and go with varying amounts of diversity. For example the following graph from a paper by paleontologist Steven Stanley (Stanley 1973 p. 491) shows the change in diversity and rate of origination for marine bivalve mollusk Genera and Families throughout the Phanerozoic (from the Ordovician to the present):

Bivalve diversity over time

Most bivalve mollusks follow a fairly conservative body plan (which is no doubt why Morris picked them to talk about) but some are fairly divergent. A good example of this is a group of bivalves from the Mesozoic called the ‘rudists‘.

Misc. rudists

As you can see from the above drawings, rudists are rather distinct from most other types of bivalves and don’t fit Morris’s glib “clams are clams” line quite so neatly.

Rudists make their fist appearance in the Jurassic period, fully 300 million years after the Cambrian and became extinct at the end of the Cretaceous. During their more that 130 m.y. tenure they became fairly common, forming large reef structures (see the photo below) like those created by Scleractinian corals in today’s oceans.  Where, since according to Dr. Morris and other YE creationists all living things coexisted prior to Noah’s Flood, were all the (hard to miss) rudists in the Cambrian? There were reef forming organisms, the previously mentioned Archaeocyathans, but no rudists, why?


Rudist (Vaccinites vesiculosus) fossils in Oman.

See the source page for the above image for more images.

Creationists have no explanation for the fossil record of rudists, the pattern for fossil bivalves in general, or anything else for that matter.

Morris: The same is true of all animals found in the Cambrian Explosion. How can evolutionary scientists use the fossils as evidence of a common descent of all life?

Right, that’s why Dr. Morris and other creationists like to talk about things like “clams” instead of say, chordata, the Phylum we belong to. There is nothing like a goldfish known from the Cambrian let alone a crocodile, dog, pigeon or human. If Morris said something like “chordates have always been chordates” he knows people would more readily see through his nonsense given that they are much more attuned to the diversity among our own Phylum than that in others (like Mollusca).

For example below we have a (possible) basal vertebrate Myllokunmingia fengjiaoa from Cambrian strata found in the Yunnan Province of China. It’s a chordate; you’re a chordate, so chordates have always been chordates, right?



Never mind the pattern of change in the fossil record that leads to the current diversity of chordates from goldfish to people, chordates are chordates.

Dr. Morris has the question backwards, at least from the POV of Darwin and other early evolutionary biologists. The question is not how do we find evidence, fossil or otherwise, for some a priori idea we have about living things. Rather it is how can we explain the pattern of the fossil record (along with a host of other patterns found in the biological world)? The only coherent, testable, explanation for the pattern of the fossil record is descent with modification from a common ancestor.

It is certainly conceivable that evolutionary theory is not accurate and that instead there is some sort of trickster deity out there that placed the fossils in the pattern we find them in order to fool us in to accepting evolution but I cannot think of any way to test such a hypothesis.

Morris: Certainly if the transitional forms had been found, they would be paraded for all to see.

Intermediate fossil forms have been found, not so much from the Cambrian and earlier (where there is less fossil evidence of any kind) but from the 500 million years since, and many of them have been “paraded” for all to see (in the scientific literature, museums, even popular literature and television), creationists simply deny, deny, deny.

Morris: Supported by such overwhelming evidence of relatedness between life’s current forms and their less complex ancestors, there would be much less controversy about the fact of evolution. But there is no such evidence. Evolution suffers from the lack of supporting data, making it impossible to determine the origin of any basic group.

This is simply more denial, and I have already recently addressed much of this from Dr. Morris so I direct my readers to my earlier post for more. See: You can tune a piano but you can’t tunicate.

Morris: The creation model predicts that no ancestral forms will ever be found, for they never existed.

And when they are creationists simply deny that they are such and keep on going. How about some positive predictions about the fossil record? Oh right that doesn’t work out so well for them…

Morris: Each basic body plan was created, without any evolutionary lineages, directly from the mind of the Creator, a fact amply supported by the data. The data show exactly what they should show if creation is true.

The data could show anything and it could be claimed to be consistent with the idea that an all powerful deity’s handiwork. God could do anything in any way, that’s what makes “god did it” an untestable and therefore scientifically useless concept.

Morris: Transitional fossils have never been found as predicted by evolution. From all we can tell, transitional missing links are imaginary, necessary only to support the evolutionary model. Perhaps evolution itself is imaginary.

That’s right John, stick your fingers in your ears and yell “la, la, la, la, I’m not listening” and all the bad’ol evidence will go away. The changing pattern of the fossil record and the existence of intermediate fossil forms was recognized by scientists (who were creationists) long before Darwin brought evolutionary theory into the scientific mainstream. Evolution provides a testable explanation for these facts. Modern creationists on the other hand have nothing but ignorance and denial.

Lastly a quick note on the following month’s edition of Acts & Facts (11-08) where Dr. Morris treated us yet more nonsense on the origin of vertebrates:

Morris: As always, it helps to define terms. First, evolution is the “descent from a common ancestor” model, the idea that all of life came from more primitive forms. Humankind came from an ape-like ancestor that came up through the mammals from an original rodent-like creature. All mammals came from early reptiles and amphibians, which all came from fish. And the fish came from some marine invertebrate like a snail or starfish, which had still earlier evolved from single-celled life. [Emphasis mine]

I addressed this silliness about fish evolving from sea stars at length in an earlier post (short answer: no one argues that fish evolved from them), this new business about snails is even sillier. No one, not even historically, has ever argued that gastropod mollusks are the ancestors of vertebrates. To even mention them in this context is not just ignorant it is deliberately and virulently ignorant.

However I think spreading virulent ignorance is Dr. Morris’s real purpose in all this and it saddens me to imagine how many young impressionable “oysters” unwisely decide to go “walking” with him and his ilk. [BPSDB]

Relevant links


Fang Zong-Jie (2006) “An introduction to Ordovician bivalves of southern China, with a discussion of the early evolution of the Bivalvia”, Geological Journal 41:303-328

Morris, John (2008a) “The Burgess Shale and Complex Life“, Acts & Facts 37(10):13

Morris, John (2008b) “The Contrasting Religions of Creation and Evolution“, Acts & Facts 37(11):13 [See this link for a rebuttal to this articles main thrust]

Stanley, Steven M. (1973) “Effects of Competition on Rates of Evolution, With Special Reference to Bivalve Mollusks and Mammals” Systematic Zoology 22(4):486-506

Valentine et al. (2006) “Assessing the fidelity of the fossil record by using marine bivalves“, Proceedings of the National Academy of Sciences 103(17):6599–6604


10 thoughts on “‘O Oysters, come and walk with us!

  1. Another really helpful post, Troy. Thanks!

    I do have one reservation. You wrote

    The changing pattern of the fossil record and the existence of intermediate fossil forms was recognized by scientists (who were creationists) long before Darwin brought evolutionary theory into the scientific mainstream.

    The changing pattern in the fossil record was surely observed; Cuvier in France and Owen in England — both eminent comparative anatomists in the first half of the 19th century — were very clear on that. But Owen opposed Darwin’s hypothesis of species transmutation and common ancestry specifically because he did not see transitional/intermediate forms in the fossil record to which he had access. Cuvier was dead before Darwin published but rejected Lamarck’s evolutionary proposal on similar grounds. They rejected the underlying species transmutation hypothesis (and therefore common ancestry) for what they regarded as a good scientific reason: they didn’t see intermediate forms in the fossil record.

    The same might be said at least in part for the late 19th century/early 20th century mutationists. They rejected Darwinian incrementalism in favor of a saltationist account.


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  5. Nice! Helpful information…. I have TONS of oysters @ home, which I find @ Fort Worth, Texas.
    *I’m goin’ there tomorrow! (3/28/13)* There’s a HUGE oyster bed over in Fort Worth, where one a’ my cousins live–super close to they’re home. Plus, I’m only 9 years old for all the adventure. I’m going to U-DIG tomorrow, too, before I go to Texas. I live in Lehi, Utah. Sorry! No more information for you other than I’ll try to post pictures of trilobites from U-DIG & some fossilized oysters as soon as I can, if I even CAN post pictures….


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