What bugged the dinosaurs? Poor research…

Thanks to Jonah Choiniere who is currently on a long term trip to the IVPP I was able to get my hands on “What bugged the dinosaurs?” this week. A recent book by husband and wife team George & Roberta Poinar, it puports to show how insects and diseases wiped out the dinosaurs (or so the hype went). I have wanted to read this for a while as the premise seemed intriguing, if very far fetched. However, as you may have guessed from the title above, I was far from impressed.

What bugged me?The book is a myriad of overstated and / or unsupported claims, poor English (they might be non-native speakers, but both work in the US and this is their third book in the language!), and most startlingly a frightening lack of knowledge about dinosaurs. Some 27 people are listed in the acknowledgements and not one do I recognise as working on dinosaurs, and it shows. Worse than that, it seems like even the authors did not bother to do any research on the subject and the errors are numerous and obvious. If you are working well outside your field, you need to do the work, or get help and there is no evidence that either occured. The thrust of the book is of course about ancient insects (and other parasites) and pathogens something the authors do work on, but of course in order to relate it to the dinosaurs, they will need to know about them and get their facts right, and here they fail badly. In most cases, I doubt the corrections would have made much difference to their arguments, but the errors are so frequent and obvious, it makes one wonder about how the rest of it was put together, and some of the arguements are incredibly tenuous. A few examples follow:

– Dinosaur taxa are misplaced in time and space (e.g. no sauropods in the Cretaceous outside of South America).

– Names used include the “Garudimimidae”, “coelurids” and “hypsilophons”.

– A reconstruction of the therizinosaur included an ‘allosaur’ head, no beak (despite it being mentioned in the figure caption) a short neck, a long body and tail, the manus was normal but with one enlarged claw (a la spinosaurs) and the three toed feet included a raptorial claw! Where did they get this from? Igananodons are shown in the ‘kangaroo’ pose, abandonned decades ago, and sauropods are shown as tail draggers and later described as living in water! Oh, and the authors drew the illustrations themselves, so excuses there!

– The following ideas are all given without citations or supporting evidence (paraphrased): dinosaurs shed their skin like lizards, most if not all juvenile dinosaurs ate insects (implied exclusively), pterosaurs were gliders, dinosaur skin was no thicker than that of modern lizards, no dinosaurs (except birds) were arboreal, hadrosaurs could feed up to 30 feet into a canopy, but ignaunodontids were limited to the bottom 10 feet, some troodons [sic] ate ants as did some dromaeosaurs, and insect diversity was 4 times higher in the Cretaceous compared to the present.

From here we get to the crux of the book – did the insects (and other vectors and parasites and pathogens) have a serious detrimental effect on the dinosaurs? There is much here of interest, if only as a catalogue of known mites, mosquitoes, ticks, bugs, nematodes and more (along with some incredible preservation of pathogens inside the amber imprisoned insects) and the evidence that they were present in the Cretaceous and that they may have (or probably did) feed on dinosaurs and cause both injuries and transfer parasites. Again though, a lack of hard evidence is obvious, while it would be silly to suggest that dinosaurs somehow avoided ticks, mites and diseases throughout their reign, it would have been nice if the authors could have demonstrated that there insects out there with mouthparts capable of piercing dinosaur hides, or that dinosaur skin was vulnerabe to the insect known at that time, or that there were skin traces with wounds known, or bones showing pathologies that could be traced to insect vectored pathogens. Perhaps this evidence simply does not exist, but surely they could have looked, and in places (like dinosaur skin thickness) statements are made, but without backups or citations.

Fully half the book consists pretty much of “parasite X existed in the Cretaceous, we know they transport diseases like Y and modern versions of X feed on reptiles, therefore dinosaurs suffered from diseases like Y”. I am being a bit over harsh here, but it really does read like that. I was more interested in the existence of these insects, their evolution and preservation, but the authors wasted their efforts trying to tie them to dinosaurs and not talk about the insects themselves. Ultimately, they propose three key issues why these animals would have been a serious threat to the dinsoaurs: 1. they would have competed for food (insects eating leaves etc)., 2. they would have spread diseases, weakening some animals and which ultimately 3. could have killed them in some cases.

The only obvious answer to this is: so what? Modern herbivores compete with insects for food and don’t suffer for it. Sure, animals get sick and die from diseases, but they tend to evolve resistence to pathogens, and behavioural or anatomical defences against parasites (e.g. thicker skins, tail swishes, seeking shade, mud wallows etc.). How is this any different to a modern ecosystem? How does a pathogen evolving some 100 million years ago seriously threaten the dinosaurs who only struggled on for another 35 million years at this point? The arguments put forward are hardly convincing:

We are shown how diseases affect animals (especially humans) and can cause deaths in large numbers. Other examples of blue tongue in domestic livestock, and the loss of Hawaiian birds of avian malaria are cited. But humans are known as poor models for such things, having only recently evolved and spread quickly, we are vulnerable to all kinds of diseases that others are not (look at HIV vs SIV). Domestic livestock are massively inbred and the tactic of slaughter every time a disease rears its head hardly help immunity evolve, and groups of small populations in isolated areas like Hawaii will always be vulnerable to newly introduced pathogens. Coming from someone who was an advisor for WHO, I am worried that this is the best they can come up with as models of dangerous pathogens (in terms of death) – are there no better examples in the literature, and if so why are they not cited? Pathogens killing off vulnerable or newly evolved taxa is no surprise. Sure, being sick is no fun, and it brings with it an increased risk of mortality (from other infections, predation etc.) but again, this is true of all wild animals – they have a parasite load, and some are worse than others. But the idea that some pathogens suddenly arose and wiped out dinosaurs seems ridiculous, and indeed it is as we shall see below.

One is left to wonder how such invertebrates could have wiped out all dinosaurs, on all continents, from all habitats at one point in time. It is suggested that land bridges and wind dispersal would soon allow vectors and dieases to spread quickly, but I am not convinced. Would a tropical disease in the equatorial African forest quickly spread to the American arctic, Australia and the Mongolian deserts? Really? Why did birds survive this onslaught? Did not some dinosaurs have big enough populations (and thus the variation) to make them immune?

This last point is challenged by the idea that insects outdid dinsoaurs in the r-selected vs K-selected arena, but the idea is poorly argued. Dinosaurs are far less at risk of this factor than mammals or birds. They are about as un K-selected as they could be given their size – they have large numbers of offspring (large egg clutches) could potentially lay multiple times a year, and yet still had long lifespans. An elephant that lives to 80 might have 15 young in her lifetime, a medium sized sauropod might lay several clutches of 50 eggs, four or five times a year. They picked the worst possible group to argue this point with.

Finally we reach the last few pages and the denoument – did these pathogens really take out the dinosaurs. Well, no. What we are told is that with the deccan traps activity (possibly combined with a meteorite impact) and other factors, dinosaurs would have been in big touble and with collapsing ecosystems. Would then, the effect of parasites and pathogens have helped them on their way? Yes. Well, obviously. I fail to see why this is news. It has perhaps never been explicitly suggested, but the book could really be summed up as “dinosaurs probably had all kinds of parasites and if the ecosystems were doomed, then this might have killed some of them”. Thanks. For. That. Page after page of devastating scenarios have been presented with dinosaurs being outcompeted for their very greenery, huge numbers of new pathogens arising and being transported by new vectors, but the conclusion is far from the drama of previous pages – the result is a whimper, not a bang. It is not like the idea is even new in this context, I think any reasonable palaeontologist would agree that many dinosaurs must have suffered from parasites and diseases and during an extinction event might be still more critical. In fact in 2005 David Unwin made note of the same idea in his pterosaur book with a little piece of fiction – the last survivng pterosaur slowly dying from an excess of ticks worrying at her skin.

Even here we are still subjected to more unsupported hyperbole namey that “Anytime an ecosystem is challenged…virulent pathogens appear and epidemics run rampant”. Really? Since when? You might think an expert on parasites and pathogens who works as a WHO advisor could provide a few examples of such spontaneously generating pathogens in stressed environments, but if he can, they were not cited. Thus we are left with entirely hypothetical ‘new’ pathogens (or ones that are already 10s of millions of years old) arising during the KT extinction and somehow helping to deliver the “knockout blow” to a group that was apparently already doomed.

I really do suspect that much of this is a result of editorial pressure. It is far easier to sell a book on dinosaur extinction than on Mesozoic ticks and fleas, but the outcome is a disaster. The dinosaur science is horribly mangled and gives off a very false impression of the current state of research, huge and sweeping (and sometimes critically important) statements are made without support or even explanation, and the one thing that should be of interest (the exceptionally preserved insects and bugs and the evidence for them carring dieases) is overlooked in trying to relate everything to dinosaurs, (and dinosaurs alone), as victims.

There is the germ of an excellent popular account of fossil insects here, and if it has to be related to dinosaurs to sell it, so be it. But that can still be done by focusing on the insects themselves: what were they like, what are they related to, how does amber preserve, are they any dinosaur-specific adaptations preserved, how do these things affect modern animals? All of these issues are largely ignored or glossed over in an attempt to make it sound like the dinosaurs were doomed through the presence of these animals, yet the denoument is that they may have contributed in some way to an already doomed race. It is hardly a dramatic and exciting conclusion after a litany of suggestive comments about the power of the parasite which themselves I think provided little real support.

So what bugged the dinosaurs (and me)? A frightening lack of research, and indeed a lack of respect for my field, and the outcome is an unsupported and unconvincing mess. The book that should have been written would have been fascinating, the book that was written is poor, and the science it communicates is inaccurate on the dinosaur front, limited on the insect front, and misleading or unconvincing on the actual extinction front.

12 Responses to “What bugged the dinosaurs? Poor research…”

  1. 1 Will Baird 01/07/2008 at 1:10 am

    Dinosaur taxa are misplaced in time and space (e.g. no sauropods in the Cretaceous outside of South America).

    Umm. I thought that one of the organizing characteristics of the NorAm faunas was a one Alamosaurus[1]…which is a sauropod. That’s not SoAm…

    A nitpick, I know, but I may be misreading what you’re writing. I’m a little short on sleep. 🙂

    1. http://en.wikipedia.org/wiki/Alamosaurus

  2. 2 Dave Godfrey 01/07/2008 at 2:43 am

    That’s a shame. I’d have been interested if they’d written a book about Mesozoic parasites, there are all sorts of interesting questions to ask. Do bird and mammal lice follow patterns of divergence matching those of their hosts? Is anything going on with fur and feather evolution and parasite diversity/co-evolution?

    If they’d wanted someone to advise them on dinosaur reconstruction there’s no shortage of people who’d have given them advice, or even offered them artwork for free.

  3. 3 Mike Keesey 01/07/2008 at 3:05 am

    “no sauropods in the Cretaceous outside of South America”

    That’s going to be rather surprising to Paralititan, Alamosaurus, Magyarosaurus, Sonorasaurus, Sauroposeidon….

    Change that to “Late Cretaceous” and you’re a lot closer to the mark, although there are still oddballs like Alamosaurus, from the Maastrichtian of southern North America, and Magyarosaurus, from the Maastrichtian of Hateg Island (now part of eastern Europe).

    Anyway, just nitpicking (no pun intended)–your general point certainly holds.

  4. 4 Nathan Myers 01/07/2008 at 10:18 am

    The K-T meteorite was a positive blessing to poor beseiged Dinosauria (not to mention Pterosauria). If not for that surcease, those poor creatures might have suffered right up into the mid-Holocene, finding no relief until Noah’s Flood itself!

  5. 5 Darren Naish 01/07/2008 at 5:27 pm

    Incidentally, there’s an excellent review of the insect fossil record that has some neat stuff on Mesozoic parasitism in it: Grimaldi & Engel’s Evolution of the Insects (CUP, 2005). It’s expensive but well worth a look.

  6. 6 David Hone 01/07/2008 at 6:34 pm

    I may not have made things clear, the authors claim there are no sauropods outside of South America in the Cretaceous, not me! I am just repeating what they said, not syaing that myself, hence my incredulity at the statement.

  7. 7 Matt Wedel 08/07/2008 at 7:16 am

    Thanks for the review. I’d been wondering whether or not to give that book a look. Think I’ll save my pennies for the Grimaldi & Engel tome Darren mentioned. I don’t know if you’ve seen a copy, but man, it’s beautiful.

  8. 8 Mason Jennings 16/01/2009 at 3:37 pm

    I agree with Johnny is some aspects – i think you are being shortsighted. This book is very well written despite a couple of spelling errors which princeton press should have picked up. But they dont claim that disease killed off the dinosaurs. But you cant deny that disease had an impact. Which is highly believable. Especially when you look at influenza, malaria, black death, aids, The Plague of Justinian, cholera, The Asiatic Flu , Typhus Epidemics, polio, Typhoid Fever, Ebola, Lassa – i mean there are a million different types of outbreaks on record that have done major damage to both human and animals populations – there has been many documented diseases that wiped out complete animal populations – australis, ebola in gorillas – wolves being wiped out – need i say more ? it is obvious that you are biased which is fine – but it is not fair when reviewing a book which offers genuine evidence that you cant deny except for making up absurd lies. TYVM.


  9. 9 David Hone 17/01/2009 at 9:50 pm

    Before I get into the details of this comment, I feel I should make it clear that this has come about in unusual circumstances. This post is obviously seven months old and has had no activity for ages before 4 comments in the last 48 hours, three of which were offensive and were deleted and the one above. The second refers to one that was deleted, and as the author cannot have seen it until it was approved I assume they know each other (in fact, thay have the same IP address!!!). WordPress records no new incoming links to this page and a google search turns up nothing, and thus I can only conclude that someone who really doesn’t like this review has only just found this post and has done something to arrange this series of comments that have appeared simultaneously. I will reply to anyhting put on here, but of course I rather prefer it if these are written politely and with a view to fair mindedness and an understanding of the problems at hand. Calling me a moron is not a good way to start and it frees me of the obligation of politeness in reply and of deleting anything else of that nature, or indeed in future from people who feel this is the way to conduct a discussion. Other readers will also have to bear with the fact that I am referring to comments they haven’t seen.
    Now, let the hammer fall:
    “Many have been shown to have calcium deficiencies wich is caused by parasites”.
    Please provide a citation, from a peer reviewed paper that shows these deficiences were cuased by parasites. You must demonstarate that a) similar parasites affect extant egg layers (and EPB of birds and crocodiles for preference) and b) these parasites were present in the Mesozoic and c) affected dinosaur eggs specifically. I can provide references of r-selection in dinosaurs, notably from Greg Paul and Burness et al. 2001.
    “research has shown that only 5% of eggs were actually capable or producing life.”
    Again a citation please. Even if this were the case, my point would still be valid – note that I am argiung for r-selection in dinosaurs. Even if only 5% of their eggs were vaible, a sauropod laying 100 eggs a year would still be outstripping an elephant say with one animal born every few years by an order of magnitude. As for the comment on calcium deficiency, I suggest you look at development of eggs. As the embyro matures it draws the calcium for it’s growth FROM THE EGG, meaning the egg loses calcium. This is seen in dinosaurs, crocs, birds and even pterosaurs. Charlie Deeming has several papers on this if you want to read into it.
    “You say animals adapt to viruses be creating thicker tails and such”
    I *actually* said “they tend to evolve resistence to pathogens, and behavioural or anatomical defences against parasites (e.g. thicker skins, tail swishes, seeking shade, mud wallows etc.).”. No a thicker tail (or indeed skin) is not a defence again a virus (generally, it will probably still stop some infections) but it will stop the insec vectors of those pathogens. Lets exaggerate – an 18” thick skin will not be pierced by even a mosquito with a jack-hammer, so it can hardly transimt any viruses during feeding can it?
    “What about honey bees getting wiped out”

    Yes, they are in big trouble. But a) they have not been wiped out, and as is inevitable they are already evolving resistance, b) they are a homogenised species of cultivated animals and as such have a smaller gene pool from which to generate resitance and thus are obviously more vulnerable (and of course this actually exaggerates the spread of the disease as well) and c) this is one species, not two entire ORDERS of diversity. I am sure you can probably wipe out a few species or even families wth a nasty pathogen, but to wipe out the dinosaurs? No. Could we really lose all mammals in this way? Really?
    Finally, one hates to be petty but if we are going into the route of name calling, you could at least have the common decency to address me as Dr Hone, since I do actually have a PhD in vertebrate palaeontology, something I cannot but help think you lack. So, there, I have basically smashed every one of your non-arguments with actual evidence and research, something you have not bothered to provide. You want to know if I have doen any research myself, why yes, all my published papers are listed on this website. You want to know why I delete ‘negative reviews’, I don’t, I just don’t publish ones that consist of swearing and insults.
    Turning to Mason (whom I rather suspect is the original “johnny”), you have also not read what I wrote. I did explicitly say “it would be silly to suggest that dinosaurs somehow avoided ticks, mites and diseases throughout their reign” – I am not saying dinosaurs did not suffer, I am saying it was probably not devestating. As I also note above in this review humans are not a great model for diseases and pathogens, and even so, important though those diseases you mention are, non of them have come close to wiping out the human race and again, we are talking about poentially thousands of species in two orders, spread over the entire globe – not a small poulation of wolves. Population swill always be vulnerable, entire species, maybe even entire families on entire continents, but entire clades? Please provide some support for the idea? And note that these are not ‘absurd lies’ but the simple reality of simple population genetics and virulence.
    People are free to leave comments and disagree with me, they are NOT free to attack and insult me, and doing so while misrepresenting what I wrote on the same page and demonstrating a complete lack of even the most basic issues I am referring to does them no credit. Feel free to be polite, if not anything you try to post will be deleted and I’ll report anything nasty to the appropriate authorities.

  10. 10 Adam 06/10/2011 at 10:32 pm

    Hey, thanks for the review. If you could find the time, could you also review Burnie’s “The Kingfisher Illustrated Dinosaur Encyclopedia” and/or Palmer’s “The Illustrated Encyclopedia of the Prehistoric World”? Those are every bit as bad as the piece of trash you reviewed here.

    I may add that Coeluridae appears to be monophyletic after all (albeit much smaller than the original, with Coelurus and Tanycolagreus being the only members).

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