Glyptodonts, Armadillos and Ken Ham’s Hyper-Speciation Model

Fossil of a large glyptodont on display. By Ryan Somma - Panochthus frenzelianus, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=4987310

Fossil of a large glyptodont on display. By Ryan Somma – Panochthus frenzelianus, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=4987310

Armadillos are curious little animals but were all of them as small as they are today?  DNA extracted from a 12,000 year old bone of an extinct glyptodont the size of a small car revealed a genetic code that clearly places this huge animal inside the group (clade) of diverse animals we collectively call armadillos. These results just published (see references) strongly suggest that the ancestral armadillos where similar in size to those that are alive today.  However, some of the descendants of those ancestral armadillos clearly evolved much larger body sizes and the hundreds of adaptions needed to support that size to become a large species-rich group of extinct armidillos we call the glyptodonts. Some of these species survived right up into the last Ice Age before finally going extinct.

We are not just talking about one unusual and rare species but rather glyptodonts refer to a group of 20 or more genera and probably a 100 or more species most of which were far larger than any living species of armadillo.  We have a rich fossil record of these species.  Many had large bony projections on their tails and huge armored shells that resembled something more like a turtle than an armadillo.   Yet, all of these are descendants of an armadillo-like ancestor that may not have been too dissimilar to those we see today.

Armadillos – another failed test of the creationist’ post-flood dispersal and speciation model. 

Here on Naturalis Historia I have written numerous times about the increasingly strong stance that literal six-day creationists have taken with respect to the rapid diversification life (eg. Ken Ham’s Darwinism: on the Origin of Species by Means of Hyper-Evolution).  Their biblical evolutionary model includes the special creation of “kinds” or types of ancestral animals which were endowed with the capacity to diversify into a multitude of species.  Most of this diversification, or speciation, is said to have occurred after representatives of each “kind” of animal was preserved on Noah’s ark 4350 years ago.

Ken Ham’s Ark Encounter theme park being constructed in Kentucky right now intends to show its guests what the animals of this post-Flood world looked like just 4350 years ago.  Those who pay $40 to see these artistic impressions will see many animals that only bear a general likeness to those we see today. These creatures will consist of an amalgamation of characteristics that combine elements from all species of a kind.  For example, there will be a single cat-like creature that will represent the common ancestor of tigers, lions, panthers and house cats.  There will be a single dog-like creature that represents a mix of fox, wolf, African wild dog and domestic dogs.  Will there be an artistic rendition of an armadillo common ancestor in a stall on the Ark? I don’t know but if there were how will they portray it?

A 9-banded armadillo. I took this picture in Ft. Myers FL last year. Image: Joel Duff

A 9-banded armadillo. I took this picture in Ft. Myers FL last year. Image: Joel Duff

You might ask, does Ken Ham and the Answers in Genesis (AiG) team believe that God created one or many kinds of armadillo? The answer is they do believe that God made but a single type of armadillos – see Jean Lightner reference.  Yes, the 21 living species that biologists place into 9 different genera Ken Ham believes are derived from but one initial species.  Even if that original species diversified into many species from Creation (6000 years ago) to the Flood (4500 years ago) only a single set of representatives were preserved on the ark according to AiG.  Since those armadillos departed the Ark they then diversified, according to AiG, via the Darwinian mechanism of natural selection into  the 21 living species we see today.

What I have described above has become commonly believed among literal six-day creationists.  They seem to think that species can be created from a common ancestor in the blink-of-an-eye via naturalistic mechanisms.  More and more I see followers of YEC literature saying that a lion and panther coming from a common ancestor is no different than two breeds of domesticated dogs being derived from a wolf. This is a woefully un-informed view of genetics but one that AiG has been promoting with great vigor in recent years.

Setting the enormous genetic obstacles to this view aside for a moment what can armadillos tell us about the YEC hyper-evolution model?

A challenging fossil record and modern geographic range:  You need to know that no fossil of an armadillo has every been found outside the new world (South and North America). And 95% of the thousands of fossils representing hundreds of species of extinct armadillos have been found in South America. The glyptodonts which are all extinct are also mostly from South America with a few that made it up to North America.

You also need to know that all 21 species of living armadillos are found only in the new world as well.  Only two species are in North America with the 9-banded armadillo now spread across much of the southern USA.

This raises a several challenging, though by no means uncommon, questions for the  young-earth hypothesis:

1) If there were armadillos before the flood how come there are no fossils of them anywhere except in South America?  And if all of those fossils are what I expect YECs believe are only post-Flood fossils then there is an utter lack of evidence that armadillos lived before the Flood.

2) If a single common ancestor of all of these hundreds of species of armadillos were on Noah’s Ark  how did those armadillos make it all the way from the Middle East to South America without leaving any evidence of their existence on other continents?

3) How did all of these species of armadillos including the extinct evolve within just a few hundred years.  All the fossilized extinct species disappeared by the end of the last Ice Age.  Ken Ham believes a single Biblical Ice Age occurred within just a few hundreds years after the flood.  If this is true armadillos had to migrate all the way from the Middle East to South America and speciate into hundreds of species including giant ones. Some had to get fossilized and most had to go extinct within a hundred years of arriving and speciating.

3) What about the giant armadillos?  Ken Ham loves to talk about how natural selection just sorts genetic information and always leads to a “loss of information.”  This is why he doesn’t refer to speciation from a common ancestor as evolution but think of it as de-evolution.  So where did these huge armadillos come from?  To grow to such an enormous size, these animals must have had many specialized physiological and anatomical functions compared to their smaller relatives.  How does that constitute de-evolution?

Natural selection or super-natural hyper-evolution?

Pink Fairy Armadillo. These are so unusual they are placed in their own genus and subfamily by biologists. By Original: cliff1066™ - →This file has been extracted from another file: Pink Fairy Armadillo (Chlamyphorus truncatus).jpg, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=32838442

Pink Fairy Armadillo. These are so unusual they are placed in their own genus and subfamily by biologists. By Original: cliff1066™ – →This file has been extracted from another file: Pink Fairy Armadillo (Chlamyphorus truncatus).jpg, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=32838442

Ken Ham’s staff believes that all species broadly called armadillos descended from a common ancestor just 4350 years ago. They claim this was accomplished via natural selection.  These 21 species though vary in tooth  number, placentation type, construction of their leathery armour shells and many physiological and behavioral traits.  How could all of these traits not to mention the massive bony tails and bony armored shells including a bony shell on their heads which no living species displays, have evolved in just a few hundred years?  Natural selection, though a powerful mechanism for adapting organisms to their environment, does not have the ability to make such fundamental changes in such a short period of time.

Ken Ham’s Darwinism is not really Darwinism at all but an appeal to un-observed forces of change which he has clothed in what he thinks is observational science – the process of natural selection. But his “observational” science provides no support for his view of rapid evolution.  Molecular and fossil data suggest that it has taken as much as 30 million years for the glyptodonts to achieve their amazing size and features compared to their armadillo relatives.  YECs have only a few hundred years to achieve the same amount of genetic and morphological diversification.  We do not observe natural selection acting at this pace and thus natural selection does not provide an explanatory mechanism for the YEC view of species formation.

Even if it was possible that all the genetic information for making a 100 separate species could be contained at one time in an ancestral pair of parents, natural selection as a mechanism for segregating that variation into defined species would take hundreds of thousands of generations to produce the complex combinations of genomes observed in species that we see today.  Genetic sorting takes a lot of time. There is no known mechanism for creating species at the pace that creationists are proposing.  The options left to them are supernatural intervention or hypothesizing that there is an entirely different mechanism of species formation that scientists have yet to discover. When the Ark Encounter opens Ken Ham will be proclaiming to the world the wonders of natural selection but this is a form of natural selection that has never been observed and for which there is no biblical evidence.  Rather than observational science, Ken Ham is relying on the unseen and hypothetical. Ironically this is just what he claims are the tools are evolutionists.

References:

The Phylogenetic affinities of the extinct glyptodonts.   Delsuc et al.  Current Biology 26 (2016)  http://www.cell.com/current-biology/pdf/S0960-9822%2816%2900121-4.pdf

AiGs view of armadillos can be seen in the following article by Jean Lightner at the Answers in Genesis website:   Mammalian Ark Kinds

 

Comments

  1. Christine Janis says:

    Great post, and not to try to be too critical, but there were several occurrences of the glyptodont Glossotherium known from the southern US in the Pleistocene. They migrated up from South America following the formation of the Panamanian land bridge, along with the ground sloths (and, indeed, the armadillos).

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  2. True there is an utter lack of evidence that armadillos lived before the Flood but then there is an utter lack of evidence that humans lived before the Flood. No fossils, dwellings, graves, tools or rubbish.

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  3. What about the giant armadillos? Ken Ham loves to talk about how natural selection just sorts genetic information and always leads to a “loss of information.” This is why he doesn’t refer to speciation from a common ancestor as evolution but think of it as de-evolution. So where did these huge armadillos come from? To grow to such an enormous size, these animals must have had many specialized physiological and anatomical functions compared to their smaller relatives. How does that constitute de-evolution?

    Unless you have specific “specialized physiological and anatomical functions” to point to, I can’t take your assertion seriously. De-evolution in huge armadillos could easily be envisioned by dysregulated existing molecular pathways of growth regulation; for example the constitutive activation of Growth Hormone Receptor by a single nucleotide polymorphism. Excess GH causes gigantism in humans. Why not in armadillos? There are many proteins in many pathways that could have such an effect. We haven’t even discussed other nutritional or environmental conditions that could affect growth, potentially even being locked in epigenetically for future generations to amplify.

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    • Christine Janis says:

      Glyptodonts aren’t “huge armadillos”, any more than rhinos are “huge horses”, or hippos are “huge cows” or lions are “huge mongooses”. They’re a separate family with distinct characteristics and a long separate evolutionary history. And they most certainly didn’t “devolve” into modern armadillos, as you imply above, which can be found alongside them in the fossil record.

      The new molecular data just shows how they are related to the family Dasypodidae (i.e., armadillos, and confirms, as if there had been any doubt, that they are not, in fact armadillos). “Giant armadillos” is just a byword for people who’ve never heard of the extinct forms, and is similarly inaccurate (although not as bad in taxonomic terminology, because it’s different families in the same order, not different classes in the same subphylum) as calling dinosaurs “huge lizards”.

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      • Christine, it appears as if your quarrel is with Joel, not me. I simply responded using *his* “huge armadillo” terminology from question number three of the post. I didn’t coin the phrase.

        It might be good if you go back a reread my comment since the details seem to have been lost on you. I made no implication of Glyptodont de-evolution into modern armadillos; in fact I didn’t even mention Glyptodonts. I was answering Joel’s question asking how the “huge armadillos” came to be so large through Ken Ham’s de-evolution mechanism.

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        • I would prefer to use phylogenetic/cladistic terminology so that I could be more precise but these are general articles. The term “armadillo” is very general here. Think of it more like “canine” or “sunflower.” It is a broad name for animals in several families that that have a common ancestor (ie. these are part of a monophyletic group). The new data suggest that the Glyptodonts fall withing that monophyletic group and thus are “armadillos” in the broad sense of the term. But there is a reason why the armadillos are given different genera name and sorted into different families (sometimes subfamilies). Groups of species diverged from that common ancestor 30 million years ago and so are very different from each other ( much more different than say foxes are from wolves) . The Glyptodonts are an early diverging group and so have evolved independently of the other “armadillos” for 30+ million years and have taken a unique trajectory making them more distinct from other armadillos. It is a bit like the birds, they are an offshoot of one group of dinosaurs and so they are part of the dinosaur clade but they evolved new features that make them distinct. Evolutionary taxonomists want to acknowledge their uniqueness and so may place them in the their own order but a strict cladist will place them in a class under the order Saurischia.

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  4. These 21 species though vary in tooth number, placentation type, construction of their leathery armour shells and many physiological and behavioral traits. How could all of these traits not to mention the massive bony tails and bony armored shells including a bony shell on their heads which no living species displays, have evolved in just a few hundred years?

    All of the discrete traits you listed could have conceivably existed in the ancestor that was on the ark. Perhaps the primordial ancestor had the full set of teeth, a bony shell and tail and a bony shell on its head. Species missing one or more of these traits could have simply lost it/them after leaving the ark. The other complex traits like the behavioral ones you mention could easily be explained by a host of random polymorphisms. After all complex traits are quite often identified by their composite complement of polymorphic alleles which can segregate rapidly and broadly to yield tremendous variation. As to “placentation type,” very little is known about the morphological variation of the placenta between species of armadillos, and even less is known about the genes responsible for this variation. In fact research shows that while a single trait, placental extension, may be different between species, the finer characteristics are actually quite similar (Rezende et al. 2012 RB&E). As such there may not have been much genetic variation required to achieve these differences. I think you are on weak evidentiary grounds to suggest that such change could not have happened when we don’t even know the genetic architecture required for such a change.

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    • Christine Janis says:

      I will confess that I read Joel’s post a bit hastily and thought that he had said that glyptodonts had been confirmed as the *sister group* of armadillos (family Dasypodidae). So, if they arise from within that group, then he’d more justified in terming them “giant armadillos”, but they really were an independent radiation quite distinct from armadillos. And, Trevor, it was indeed glyptodonts Joel was referring to when he was referring to “huge armadillos”

      “We are not just talking about one unusual and rare species but rather glyptodonts refer to a group of 20 or more genera and probably a 100 or more species most of which were far larger than any living species of armadillo. ”

      By “far larger” think “an order of magnitude”. Also they were distinctly different from armadillos in features of their skull and body armor. You’re not going to turn something that weighs a couple of tons in a 2 kg armadillo (or even a 200 kg “giant” armadillo of today) by deregulation of growth hormone. You might as well posit that deregulating growth hormone would turn a giraffe into a goat in a few generations. Joel’s point remains: there’s no way you can get this diversity of armadillos and glyptodonts (not to mention other related, extinct beasts like pampatheres) in a few hundred years of “hyper evolution” (which, of course, has never been observed, or even mentioned in historical records).

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      • Hi Janis, take a look at the new Current Biology paper that I link at the bottom. I am not very familiar with the taxonomic history of these groups but it sounds like there has been a fair amount of diverse opinion. However, this new genetic data would seem to place the Glyptodonts inside the clade of all things broadly called armadillos and so I don’t think it would be improper to call the Glyptodonts a type of armadillo assuming the molecular data are providing us with the correct phylogenetic relationships.

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        • Christine Janis says:

          Apologies for my earlier confusion about what the paper (and you!) actually said. Yes, the data do seem fairly conclusive, but note that they’ve now made the Dasypodidae a separate family including the animals that are familiar to people as “armadillos”. I guess I’d say that glyptodonts are armadillos the way that whales are artiodactyls (a bit more of taxonomic stretch, but still)

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          • It seems better to me to have several families and to create different common names for each to emphasize just how different these groups are. Unfortunately, armadillo has been applied as a common name very broadly and so when this story hit all the headlines talked about Glyptodonts being shown to be an amradillo. Since my main point wasn’t about taxonomy and YECs themselves are willing to lump all of these into one group they call armadillos it only made sense to use the common understanding and not get into the taxonomy in my article.

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      • Again, Christine, the relationships between glyptodonts and armadillos is not germane to my point. And since Joel stated that these are broad posts, I’ll continue using the phrase “huge armadillo” for ease of discussion.

        Joel asked how armadillos get huge and I gave one potential explanation which you dismissed with an unfounded assertion. You’ve not explained how you know that “You’re not going to turn something that weighs a couple of tons in a 2 kg armadillo (or even a 200 kg “giant” armadillo of today) by deregulation of growth hormone.” I hypothesized the well known, real world example of dysregulated growth hormone, and you simply asserted the contrary with no explanation. Have you or anyone else created a transgenic armadillo with a constitutively activated growth hormone receptor and shown that it doesn’t modify armadillo body size? If not then I find no validity in your support for Joel’s conclusion.

        Moreover, strong GH-related growth phenotypes are well documented in humans and numerous animal models, which you can’t simply ignore. A number of GH SNPs have different frequencies between a variety of cattle species (Singh et. al. 2014 Anim Biotechnol), and a single amino acid residue is known to determine is species specificity (Souza et. al. 1995 Proc Natl Acad Sci USA). These and a host of other papers demonstrate that GH is a key determinate of body size between species. I also mentioned that GH may only be one of many modulated pathways responsible for the size difference between the species, so GH alone doesn’t have to account for the entire difference. My hypothesis is easily testable by comparing important growth related pathways between the armadillo species. If you can demonstrate there is no difference then you can make your assertion. But you can’t just dismiss a valid hypothesis because it disagrees with you. Scientists support and dismiss conclusions with assertions based on experimentation, not by assertion alone.

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  5. According to the Current Biology article, the extant armadillos are paraphyletic with regard to glyptodonts. The article says: “Glyptodonts were a group of ambulatory specialized herbivores that
    reached giant size bracketed between two extant clades of armadillos that do not share either of these characteristics.” The important word is ‘bracketed’. In fact, the article includes the Glyptodonts in the familie Chlamyphoridae – in the midst of extant animals. Whether the order Cingulata or the families Dasypodidae and Chlamyphoridae are made baramin does not matter for the argument: Glyptodonts diversified and died out in 400 or so years according to YEC, from a small sized ancestor.

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  6. Thanks for the post. Having never heard of these creatures before, that glyptodont fossil image at the top is spectacular. Being naturally more familiar with dinosaurs when it comes to the domain of large extinct creatures, I’m fascinated by the little I’ve stumbled on regarding the early/extinct (Eocene?) mammals… are there any good resources you’d recommend for learning more about the different kinds? (preferrably with lots of fossil images – though artist renditions are ok too)

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  7. Christine Janis says:

    “I hypothesized the well known, real world example of dysregulated growth hormone, and you simply asserted the contrary with no explanation. Have you or anyone else created a transgenic armadillo with a constitutively activated growth hormone receptor and shown that it doesn’t modify armadillo body size?”

    You’re giving an example from humans, a within species example, which is an entirely inappropriate analogy. Glyptodonts were different from armadillos in many ways besides size, which is why they are recognised as a separate lineage.

    “A number of GH SNPs have different frequencies between a variety of cattle species —”
    “These and a host of other papers demonstrate that GH is a key determinate of body size between species.”

    The papers don’t say that change in GH could turn one species into another (and, BTW, goats and sheep aren’t “cattle”). Could a bison turn into a goat, just by deregulation of growth hormone? Is a goat just a small bison?

    “My hypothesis is easily testable by comparing important growth related pathways between the armadillo species.”

    Only if you assume that a glyptodont is simply a very large armadillo. Which is demonstrably untrue.

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    • Correction: “Cattle” should say “livestock” as the paper noted.

      Again I’m not referring to glyptodont-to-armadillo evolution. I’m making a case for how one armadillo becomes a larger armadillo as question three asked (how did huge armadillos come from smaller ancestors; the ancestors being armadillos not glyptodonts). The examples that I’ve given more than establish the principle role of growth hormone in body size and are only a small sampling of the literature out there in many animals. Thus it is logical to hypothesize that at least some of the increased size of the larger armadillos compared to their smaller ancestors could be due to a “de-evolution” mechanism such as loss of regulation of GH.

      BTW, I don’t imagine that a bison could turn into a goat by altering GH. That’s why my hypothesis doesn’t suggest such a phenomenon. Such caricatures of my statements only distract from the issue at hand. Nonetheless, I think I’ve adequately demonstrated that a small armadillo becoming a huge armadillo is not a prohibitive change that would take hundreds of thousands of generations or millions of year, but perhaps only the loss of a few key genetic regulatory control points.

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  8. Do you have any comments on the unexpected results from this new study about how “embedded” the glyptodont was found to be within the armadillo family?

    It’s not all that surprising to find that glyptodonts are in fact armadillos, Darin Croft, a paleomammalogist at Case Western Reserve University who was not part of the study, tells The Christian Science Monitor. But it is intriguing that they are so deeply embedded in the group, he says.

    In fact, the DNA analysis suggests that the car-sized armored mammals are most closely related to both the smallest and largest living armadillos.

    “Glyptodonts are the sister taxa to the pink fairy armadillo. If you look at the shapes and sizes of these two creatures, no one would have guessed that,” evolutionary geneticist Hendrik Poinar, a senior author on the paper, tells the Monitor.

    (CSMonitor article about the study)

    If a giant glyptodont is more related to tiny armadillos than anyone would have guessed just looking at the bones, how much other variation in proposed but non-sequenced ancestral lineages might be possible? (I’ve sometimes read claims by creationists that molecular clock / genetic sequencing -based timelines hopelessly conflict with fossil/geological- based timelines, but I’m fairly ignorant about the overall subject)

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    • Christine Janis says:

      Nobody ever thought that glyptodonts weren’t, at some level (probably sister group), related to armadillos (because they do share some morphological features), but not necessarily embedded within the group. However, the best analogy here is the finding, from molecular biology, that whales are embedded within the Artiodactyla. Doesn’t change the fact that whales aren’t spectacularly different, and evolved along a completely different trajectory, than terrestrial artiodactyls —- but as nobody ever doubted that the ancestral protowhale had to be some small terrestrial mammal, well it might have been something like Indohyus. Likewise, even if glyptodonts were not phylogenetically embedded within the armadillos, the ancestral glyptodont probably looked a bit like a smallish, generalized armadillo. (But you can’t reverse that process with a deregulation of growth hormone.)

      The *real* surprise would have been if the molecular data had shown glyptodonts not to be related to armadillos at all. As it is, they’re just more closely related than we thought.

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      • “(But you can’t reverse that process with a deregulation of growth hormone.)” Again, a straw man argument and an assertion without the proffer of evidence. Difficult to take this seriously.

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  9. Christine Janis says:

    ‘“(But you can’t reverse that process with a deregulation of growth hormone.)” Again, a straw man argument and an assertion without the proffer of evidence. Difficult to take this seriously.’

    What is difficult to take seriously is your assertion that growth hormone deregulation can turn one species into another species in a totally different lineage (whether subfamily or family is irrelevant here). Let me make the point again. Deregulating the growth hormone in a bison might give you a smaller bison, but it won’t give you a goat. Deregulating the growth hormone in a human might give you a smaller human, but it won’t give you a bonobo.

    An armadillo is not simply a small glyptodont; they are distinctly different (and no, it’s not simply allometry). Body size might be changeable with growth hormone increase or decrease, but evolutionary processes (or, if you prefer, transformation into a different species with different anatomy unrelated to size) are not.

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    • Ah, now we agree! My point all along was that if you want to explain how a large armadillo is derived from a smaller armadillo (which was the apparent question above), growth hormone could explain part of that process. If you want to explain a transformation between glyptodont and armadillo, I’m sure that would take more than modulated GH, but that was not how the question was posed.

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  10. I think your a little hard on AIG, do they explicitly say armadillos come from a single ancestor? Obviously no one really knows.

    I think you may be looking at Aig natural selection backwards. Its not a matter of how the armadillos evolved to be bigger and bonier, but rather as you stated referring to losing information, started bigger and bonier and devolved/adapted to what we have today. Mind you, in a climate change unlike anything we have been able to observe or deal with in the past couple millenia.

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  11. I couldnt quite understand what aig was trying to say about the armadillo kind. But wiki puts glyptodonts in the Chlamyphoridae family, i understood that aig was only claiming the Dasypodidae family to be a kind not the whole order cingulata ? Either way i agree that they are bold claims if they are being put in a journal, idk thats what that article is. Also i find it to be trivial and personally dont really care, as curious as i am about which kinds were on the ark.

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