Tetrapod Zoology

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Imbued with god-like powers, the ever-inspirational Mathew Wedel, aka Dr Vector, has wondered what sort of experiments he might play with the biosphere in order to observe the evolutionary results. Given that I just posted an article the other day on Godzilla, it would be a good idea to avoid the whole speculative zoology area for a while. After all, I don’t want to get a reputation. But I have to strike while the proverbial iron is hot and, don’t worry, we’ll be back to rodents, passerines and small, dull brown lizards soon enough. Sticking only with tetrapods (of course), what neat extrapolations and speculations can we come up with?

Incidentally, my recent discussion (in the Godzilla post) of kaiju-biology caught the attention of Mark Meloon, the creator of the awesome kaiju-biology page that I linked to. His email made me laugh; here’s what he had to say….

I saw your recent article on The Science of Godzilla and figured I should drop you a line. You cited an old web page about kaiju-biology that I wrote way back when I was a grad student at Caltech (Alan mentions on http://kaiju.boomcoach.com/ that the original kaiju-biology page was part of my large Godzilla site) and it brought back happy memories of avoiding doing my Ph. D. research by watching giant monster movies. I’m glad you enjoyed it and that it’s still making people smile! Yes, I am actually a scientist,
although I’m working in artificial intelligence now instead of kaiju-biology. Thanks for the overview on the real scientific work on Godzilla. I had lost track of the cutting-edge research being done in this area. Rest assured, that if the country needs me to put my talents to work once again, I will not hesitate to answer the call!

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Back to the matter in hand. The more I learn about science fiction, the harder I find it to think of anything that’s truly novel as goes alternative history and hypothetical evolution. Future animals have now been done to death, what with Dougal Dixon’s After Man, Man After Man, and The Future Is Wild, plus there are the classics like Wells, J. T. Bass, Simak and so many more. I once acted as advisor to a ‘future evolution’ scene produced by Steve White: we had smart tool-using finches and millions of tiny eusocial mole rats (the latter inspired by the discussion in Lavers (2001)) living alongside giant combat chickens, big rodents (including ‘pachybaras’) and neo-sebecosuchian crocodilians dubbed velocisuchians. All of our decisions were actually based on real things that happened, or are happening, in the real world. The result is Steve’s painting, used at the top and borrowed from his excellent Thunderlizard site.

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‘Alternative’ dinosaurs and other animals have also gotten their due, with Specworld including a pretty impressive pantheon of hypothetical animals that have evolved on a parallel Earth where the end-Cretaceous event didn’t happen. Some of Specworld’s animals (particularly the birds) are lame, but others (like the marine monotremes and mosasaurs) are superb [adjacent pic shows Hobb's leviathan, a mosasaur from the oceans of Specworld, from here]. Dougal’s The New Dinosaurs invented a modern fauna of post-Mesozoic mammals, pterosaurs and dinosaurs, though few of the animals he came up with seem likely or reasonable (Dixon 1988) [image above shows some of the creatures from The New Dinosaurs, by me: go here for bigger version]. Greg Paul (1990) provided a detailed critique of Dougal’s ‘improbable view of Tertiary dinosaurs’ and proposed a rather different modern day where big mammals evolved alongside conservative small ornithischians, grazing hadrosaurs and geese. We also have a few other well-known ‘alternative evolution’ experiments like Dale Russell’s dinosauroid (for my take on smart theropods and dinosauroids go here). Moving away from planet Earth, multitudinous alien creatures have also been dreamt up: many poor, some good, and some excellent, and finally there are bizarre, wonderful, imaginary animals of all sorts, like Nemo Ramjet’s creatures (Nemo is available for hire as an illustrator, incidentally). This list is not meant to be comprehensive!

We can always make the argument that these assorted speculative creations are not necessarily random and pointless, but perhaps useful in highlighting the patterns of the past and present, and in informing us as to our fate and future. Indeed there are good solid reasons for making informed speculations about both alien life, and about future evolution. So-called extinction management is likely going to become increasingly important in future as global climates change, and we need the knowledge of the past and present to predict how lineages might respond to the changes.

Matt’s new ideas are nice and good: which animals might populate a future hot-world Antarctica?; what would have happened if Antarctica and South America remained linked and the circum-polar current never formed?; what if non-avian dinosaurs died out everywhere except Australasia?; what if Pangaea never broke up?; and what if turtles inherited the earth? He ended his post with ‘Seriously. If you had the aforementioned [god-like] powers, what experiments would you do?’. In the words of King Mufasa (father of Simba in Disney’s The Lion King – how’s that for a trendy reference), ‘Is that a challenge?’ (better might be Bugs Bunny: ‘Of course you realize… this means war’).

Here are two of my favourite, most non-standard speculative evolutionary scenarios (it was going to be more than two, but I’ve run out of time). If you’re artistically gifted and with lots of free time on your hands, feel free to set up a website where you explore these scenarios to the full :)

Squamate World

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Firstly, we have Squamate World. Mammals never really get going in the latter part of the Cretaceous, and while amphibians, turtles, birds and crocodilians continue as normal, it is squamates that come to dominate the post-Mesozoic biosphere. Herds of millions of herbivorous agamids dominate Eurasia and Africa, and giant armour-plated (but still sprawling) omnivorous skinks and mastigures inhabit scrublands, deserts and uplands across the Old World. Lacertids and skinks evolve unparalleled diversity, with small insectivores and mid-sized generalists occurring across all environments, from forest floors to tree tops. Giant predatory short-skulled amphisbaenians prey on large surface-dwelling animals [adjacent image, from Digimorph, shows the 10 mm skull of the predatory amphisbaenian Anops kingii. Imagine enlarging this animal so that its skull was 30 cm long]. Crotaphytid iguanians in the Americas evolve erect gaits and endothermy, and become long-legged giant cursorial predators. Across North America and Eurasia, diverse venomous helodermatids and big geckos skulk around at night. Big terrestrial and scansorial anoles dominate the American tropics and big bizarre iguanians are spread across the islands of the Pacific. The lack of amphibious and aquatic mammals means that several squamate lineages take to the seas, with Mediterranean lacertids, Australasian skinks, Pacific iguanines and American anguids all evolving amphibious and aquatic forms. The seas are filled with untold billions of sea snakes, and not just small ones, but giant ones too. Boids and their kin never go through an Oligocene-Miocene ‘dark period’ and Eurasia and North America are full of sand boas and related forms, and colubroids never really took off because rodents didn’t; instead small, gracile boas and pythons undergo a radiation and mostly prey on tiny diverse lacertids and geckos. Varanids in SE Asia and Australasia, and iguanines in South America, evolve endothermy and enhanced encephalisation. Short-faced arboreal iguanines evolve increasingly complex societies and cultures from the Miocene onwards.

All of these speculations are inspired by reality, honest.

Oligocene World, aka Slinker World

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Here’s another one. Neogene drying doesn’t occur, and hence the development of plains and of wind-pollinated floras dominated by grasses never really get going; in other words the subtropical and temperate woodlands of the Oligocene remain covering the better parts of the continents. Apart from cool polar tundra, terrestrial environments are essentially wall-to-wall woodland and forest, making Earth like a big version of Endor (the forest moon from Return of the Jedi, of course). Other than that, everything else pre-Oligocene is broadly the same as really happened.

Devoid of the opportunity to evolve mid-sized ecotone and open-habitat forms, hoofed mammals mostly remain as small, browsing slinkers for the rest of Cenozoic history [rather similar to the chevrotain pictured above: image from here]. But the forests are filled with thousands and thousands of them. Proboscideans, notoungulates, rhinos, horses, suiforms, deer and bovids all diversify at small body size and stay that way. They are preyed on by big forest-dwelling eagles and sebecosuchian crocodilians. Carnivorans remain at small body size too, but all lineages remain scansorial and only a few species evolve to prey on the slinkers. Mostly the carnivorans prey on birds, bats and scansorial primates. The subtropical and temperate woodlands of North America and Eurasia are filled with plethodontid salamanders, with absurd niche packing occurring across the board. Consequently there are lots of arboreal, scansorial, aquatic and fossorial plethodontids of all shapes and sizes, and multiple reversions from and to biphasic life history and direct development. Rivers and lakes are inhabited by small, mid-sized and giant predatory plethodontids, the biggest of which (err….. 5 m long!) ambush slinkers when they come down to drink or go for a swim. Some slinkers inhabit the coasts of tropical Asia, and it’s these that have given rise to whales, so the cetacean fauna is the same as the real Earth one. And there are lots of meiolaniids, caecilians and pangolins…

Now ain’t that pretty?

UPDATE: this post and others have inspired Matt to produce two more posts on speculative zoology, both are required reading on this subject. Click here and here.

Refs – -

Dixon, D. 1988. The New Dinosaurs: An Alternative Evolution. Salem House Publishers, Topsfield, MA.

Lavers, C. P. 2001. Why Elephants Have Big Ears. Phoenix, London.

Paul, G. S. 1990. An improbable view of Tertiary dinosaurs. Evolutionary Theory 9, 309-315.

Comments

  1. #1 Maureen Lycaon
    February 14, 2007

    Here’s a question for you: in Slinker World, given that there are no significant plains, would hoofed mammals have ever lost toes in the course of evolution? Or would horses (for example) have retained three toes, or even four or five?

  2. #2 Darren Naish
    February 14, 2007

    Excellent question. It seems that hoofed mammals lost side toes as they evolved cursoriality: on Slinker World the hoofed mammals aren’t cursorial, so there’s no pressure to reduce the number of digits. The horses would therefore retain four manual digits and three pedal ones (as was the case in the earliest horses).

    Thanks for your comment… is Lycaon your real name?

  3. #3 John McKay
    February 14, 2007

    One final alternative dinosaur work that deserves mention is Rick Meyerowitz’s Dodosaurs. Meyerowitz is the artist who produced the famous 1971 Mona Gorilla cover for National Lampoon (back when Lampoon was actually funny). Dodosaurs was a couple of museum style murals of failed dinosaurs. Later he developed the idea into a book, but I think it’s been out of print for about twenty years. I thought about this book just recently witht he news pieces about “biplane” primative birds. One of the dodosaurs–possibly the pterribledactyl–was shown as a flightless triplane (red, with maltese cross markings) throwing itself off a cliff and cratering in the earth below.

  4. #4 Alan Kellogg
    February 15, 2007

    For my part I asked myself what sort of world would you get were dragons to exist. Dragons as they appear in fantasy games and modern fictions. I soon realized that to get that sort of dragon, instead of the animated blimps presented by the Discover Channel, the world would have to include a phenomenon our world cannot experience. For to get the giant, muscular, flying animals we call dragons, muscle power alone won’t do the trick. While gaining lift from internal gas bags would weaken them, and make them vulnerable.

    No, the only way to have gigantic (even enormous) flying dragons is by allowing magic.

    Along the way I also decided to have a certain asteroid miss Earth and hit Venus instead. Means some dinosaur lines survived into the Paleocene, though the changes wrought by the Deccan Traps put paid to the great majority of dinosaurian lines.

    Including working magic also allowed me to come up with modern day basiliskid dinosaurs (classified among Aves BTW) with the ability to paralyze with a glance.

    The problem of the dragon’s hexapedal state I answered by introducing a glitch in fetal development, where forelimb development is “duplicated” further down the embryo. Though the course of evolution as modified that as well. The same solution applying to non-dragons as well. (To keep this short it means that griffins, hippogriffs, and pegasi are archosaurs and not mammals, and thus more closely related to dragons than they are to Man.)

    Obviously if you must stay acceptably scientific what I did won’t be a bit of help. :)

  5. #5 Keenir
    February 15, 2007

    hi.

    I trust you are well.

    Its been far too long since I’ve seen anyone dedicate that much space to the topic of allohistorical evolution. Thank you, kind and good and sage sir.

    I tried to find the picture you mentioned (of the image at page top with the eusocial birds et al), but could not locate it. Sorry.

    As to SPEC, you might’ve had an outdated link to the site, which is presently here http://www.bowdoin.edu/~dbensen/Spec/Index.html and is considering moving to a new and better site in the future. (just so you know)

    -Keenir

  6. #6 Sordes
    February 15, 2007

    Creating hypothetical animals, also one of my very farourite hobbies since many many years…I have also played alot with hypothetical animals and drawn and written alot about them. What I always liked very much was the situation of a large isolated island, where some colonists develope massive adaptive radiation, similar to the lemurs of Madagascar. On one of this islands (simimlar to New Zealand) no terrestrial mammals or large reptiles existed, and bats similar to Mystacina robusta and tuberculata evolved to an enormous variety, which conquered all the ecological niches, which are normally occupied by normal mammals (and note, I did NOT steal the ideas of Dougal Dixon), mainly by loosing their ability to fly. From comparably conservative arboreal forms which are similar to pottos or sloths, to a small mole-like burrowing bat with enlarged thumb-claws, a small anteater with a long tongue and a narrow snout. The once arboreal potto and sloth-like species evolved to larger terrestrial forms, which look a bit like a mix between ground sloths, giant lemurs and, of course, bats. But there are also hunters, looking a bit like oversized full-terresrial vampire bats, whose largest species are about the size of a big mastiff, and which are armed with enlarged thumbclaws (similar to Thylacoleo) to bring down the cow-sized herbivorous ground-sloth bats. Another path of this imaginary bat evolution ended in fox-sized long-leged priscivorous bats, which used to hook-like thumb-claws to catch fish and other small animals in the water, occupying the niche of herons and storks. There were also some more, but I dont remember anymore all of them.
    There was also a tropical island which was conquered by crocodiles, which evolved to dozens of different terrestrial forms, and you would be astonished if you would set a foot on chameleon-island…
    Some of my animals which could well live at Slinker-world are for example my Qupaki, a small duiker-like hooved animal which evolved a long sticky tongue and other anatomical features to eat ants and other insects, or the giant rock-salamander, an alligator-sized sluggish amphibium with a bloated skin which has similar abilities to change shape and colour like an octopus. Or the big, mainly arboreal living leopard-monkeys, which hunt in small packs other primates and small hooved mammals in the jungles.
    Another idea was a biotop which was dominated by terrestrial crustaceens and vertebrates. But none of the tetrapod vertebrates, but several lines of fish which independently evolved a more or less terrestrial livestyle, for example the bunch of terrestrial eels which evolved in some burrowing caecilian-like animals, or some terrestrial anglerfish (which do even on earth resemble more tetrapods than some animals which are in fact tetrapods, but lost their name-giving limbs) and some other things like this. Sadly we can´t play with evolution like the wizards of discworld with the experimantal “round-world”.

  7. #7 Dave Hone
    February 15, 2007

    Kellog.

    For dragons, you could also lower gravity and / or increase the atmospheric density. That would give a far higher unit lift per wing area and mass of dragon.

    And don’t think that hollow bones would not make a colossal difference to mass without affecting strength significantly. Birds,, bats and pterosaurs all cut their mass enormously yet retained strong skeletons.

  8. #8 Sordes
    February 15, 2007

    Another interesting and really important thing is hypothetic paleontology. This post is about animals which could develop in the future or which could have developed and live now on an immaginal world.
    But on our real world, there is also still much room for spectacular animals which MUST have lived once, but which we still dont know. There are thousands of tranistional forms, and we know the evolution of many living and extinct animals very well. But about many others we know nearly nothing, and will probably never known anything, for example because all fossils were distructed during geological processes.
    Hypothetical paleontology is nothing new, as already many decades ago people tried to imagine how the “missing-links” probably looked. For example the pre-Archaeopteryx, which was already painted by Burian as a climbing reptile with feathers on arms and legs (and with omnius similarity to Microraptor gui). I had several thought about this issue, when you wrote some months ago about the unknown adaptive radiation of prehistoric animals, and that every fantastic critter which was discovered, must have had a whole family of similar relatives or even ancestors.
    One thing I would for example really like is a fossil of a primitive bat which was still not able to fly, or even better a whole line of them. Another extraordinairy modern animal, whose fossil history would be surely very interesting, is the narwhale. Today the males have normally one enlarged left upper incisor, which grows over the mouth out of the skin. The question is now, how looked their ancestors? Since when grow the teeth outside the mouth, and since when is it straight forwards orientated? And how long had they still two tusks? This case is not comparable to the completely linear evolution of bigger body-size or longer limbs, because there were several “angles” in their evolution.

  9. #9 David Marjanovi?
    February 15, 2007

    Spec has started moving to my university server (almost unlimited webspace for free!) — it’s just that I am the limiting factor for uploading stuff, and I hardly ever have enough spare time at once. A few pages, usually updated over those from the bowdoin server, are already at http://spec.int.tc (if that doesn’t work, try http://www.unet.univie.ac.at/~a0000265/Spec/index.html); many pages that are unfinished but way advanced over their bowdoin versions (Dan ran out of time, too) or are altogether new can be found here http://www.unet.univie.ac.at/~a0000265/Spec.htm.

    Enjoy. And remember, contributors are always welcome…

  10. #10 Poseidon
    February 15, 2007

    it would be a good idea to avoid the whole speculative zoology area for a while

    There is no rationale conceivable to me that would satisfactorily support that argument.

    Thank you, Darren. Thank you for being speculative. My heart leaped when I saw this post, and the picture that accompanied it. This is why I come back every day: in the hope of seeing a post just like this.

  11. #11 Darren Naish
    February 15, 2007

    Sordes: you might be interested to know that there are some hypothetical proto-bats illustrated in Hill & Smith’s classic British Museum volume. They start out, predictably, looking shrew-like.. which might be debatable given recent evidence for monophyly of Pegasoferae, a clade composed of bats, perissodactyls, carnivorans and pangolins.

  12. #12 Darren Naish
    February 15, 2007

    Oh yeah.. as for proto-narwhals, the possible ancestral morphology might be hinted at by the supposed beluga-narwhal hybrids (dubbed ‘beluwhals’) reported by Heide-Jorgensen & Reeves (1993). These animals had protruding incisors, but they were tiny compared to the big one of Monodon. I’ve mentioned these bizarre whales before and must blog about them one day. Actually, you’ve inspired me, stay tuned…

    Ref – -

    Heide-Jorgensen, M. P. & Reeves, R. R. 1993. Description of an anomalous monodontid skull from west Greenland: a possible hybrid. Marine Mammal Science 9, 258-268.

  13. #13 David Marjanovi?
    February 15, 2007

    And, of course… how dare you say our birds are lame? Have you managed to overlook the Penguins of DEATH!!!? Pray to the Mitey Ozgod that the Giant Kaiju Penguin of DOOM!!!!1! isn’t resurrected to pay you a visit.

  14. #14 Maureen Lycaon
    February 15, 2007

    Darren: thank you for responding to my comment. I guess that also means no ungulates would become social, since herding may have been closely tied to the move out into open habitat where members of a group could see each other.

    To answer your question, nope, this is a pseudonym, not my real name; I originally created it for posting my fiction on the Net some years ago. These days, though, I use my LJ to rant about paleontology at least as much as for posting my stories.

  15. #15 Alan Kellogg
    February 16, 2007

    Howe,

    But then you’ve got all the other baggage associated with dragons, thermic halitosis for one. Be simpler just to use another part of the multiverse rather than trying to cram them into this one.

    When Da Rulz say a green cheese Moon is not possible, then a green chese Moon is not possible.

  16. #16 Sordes
    February 16, 2007

    Thanks for this information. If I remember correctly there is also a drawing of such a proto-bat in your flickr-album. I dont suppose very much surprises if we will ever have a filled line for transitional forms of bats, especially because we have today many animals which show similar stages of gliding-adaptions. But its really strange, since the last decades we have uncountable fossils of bird-dinos and dino-birds showing a wide variety of of in betweens, but in the case of bats and pterosaurs we have nearly nothing.
    The information about the supposed hybrid is really interesting. I also suppose that the ancestors of narwahles were once beluga-like, and that the males once developed enlarged incisors for inter-species-conflicts similar to many beaked whales. But there are also many interestig questions, because at one time of their evolution comparably drastic changes must have happened. Its a big difference between one and two teeth or in which direction the teeth were standing (I just think about the even stranger odobenocetops-species, which make some problems because their teeth were in the opposite direction). And when became the tusk a highly sensitive organ?
    Another problem of the “when-did-it-happen-and-how-did-they-look”category is the date when whales lost their fur. It seems not very problematic as even well-adapted marine animals like seals and otters still have a pelt, and in general Ambulocetus and its fellows are depicted with a fur. Carl Buel made a beginning of the loss of fur as he portrayed Ambulocetus with a naked, sensitive snout (what I for my part dislike a bit, it looks also somewhat unhealthy with this naked pink region at the top). But even given the fact that the ancestors of whales and hippos became separated many million years ago, things become although more complicated because they are much lesser adapted to an amphibious way of life than Ambulocetus and have yet no fur, even the more terrestrial pygmy hippo…So probably whales lost their fur also at a very early stage of their evolution and not after they were already at-least seal-like, and all the nice reconstructions would be false.

  17. #17 Tim Morris
    February 16, 2007

    Hey Darren, I’ve admnired your amazing blog (well blogs, now, sort of) for ages.

    I’m taking you up on your little anecdote. I’m setting up squamate world.

    http://squamozoic.blogspot.com/

    Just as a blog for now, but who knows? Feel free to pop by, mind you, it’s just starting up. I’ve posted on what “happened” to the other animal groups first, to get it out of the way.

  18. #18 David Marjanovi?
    February 16, 2007

    I thought I had submitted another comment before the one that got through. Here it is again:

    Spec has started moving to my university server (almost unlimited webspace!) — it’s just that I am the limiting factor for uploading stuff, and I hardly ever have enough spare time at once. A few pages, usually updated over those from the bowdoin server, are already at http://spec.int.tc (if that doesn’t work, try http://www.unet.univie.ac.at/~a0000265/Spec/index.html); many pages that are unfinished but way advanced over their bowdoin versions (Dan ran out of time, too) or are altogether new can be found here http://www.unet.univie.ac.at/~a0000265/Spec.htm.

    In spite of all those delays, further contributors are always welcome. Go to the Latest page of Spec to find out how to join.

  19. #19 Thomas R. Holtz, Jr.
    February 16, 2007

    John Merck & I once speculated on the “Everything at the Triassic Extinctions Went Backwards” world: that is, turtles and dinosaurs and mammaliforms and crocodyliforms and squamates and pterosaurs and ichthyosaurs and plesiosaurs and so forth died out, but drepanosaurids and dicynodonts and non-crocodyliform pseudosuchians and others made it through. (Although we concentrated on tetrapods, we let the euconodonts survive as well, seeing as they got ripped off in the historic timeline…).

    Inspired in part by Effigia, it looked pretty clearly that the pseudo-Jurassic onward was going to be a pseudosuchian world. Still trying to figure out who gets to be the next group to become powered fliers, though…

  20. #20 Raymond
    February 16, 2007

    Specworld avians lame?!?

    May the Emperor of Penguins unleash his Ginaz Gentoos on you.Ye fowl BLASPHEMER!!!!

  21. #21 Pavel Volkov
    February 17, 2007

    Sordes, there are many blogs, groups and sites devoted to futuristic evolution in WWW. If you have interesting ideas, you may post and discuss it there. For example, go here:
    http://tech.groups.yahoo.com/group/philosphica-dixonia/
    or here:
    http://s7.invisionfree.com/Metazoica/index.php
    If you know Russian, you may even go here:
    http://sivatherium.borda.ru/

  22. #22 Dr Vector
    February 17, 2007

    Dude! Thanks for the shout-out. I had no idea that this speculative zoology stuff would appeal to so many. People have proposed a lot of cool scenarios, both here and at Ask Dr Vector.

    Tom, I especially like the “Tri-ass-backwards” world you dreamt up with Merck. It is very tempting to wonder how much of a nudge it would have taken to make Effigia and the other rauisuchians the founders of a Mesozoic-dominating alternasaur radiation, while ornithodirans petered out. It’s starting to look like a very close race there in the Late Triassic.

    In my recent speculative zoology with Randy Irmis (documented here and here) we eventually came around to the impacts that humans are having on the biosphere now. As Randy pointed out, if you like evolutionary experiments, now is a great time to be alive. Every plowed or paved acre is an experiment in habitat fragmentation. Every invasive species is a new ecological and evolutionary experiment. If the anthropogenic extinctions that are going on right now hit K/T severity, it will be an interesting future world. There is certainly a taxonomic component to anthropogenic extinctions, but the more important question seems to be, “What species get along well with humans?” I expect the future fauna to be made up of descendants of rats, pigeons, opossums, armadillos, domestic dogs and cats, Gambusia affinis, coyotes (which seem to do better the more we persecute them–David Quammen’s essay “To Live and Die in L.A.” is an accessible survey), white-tailed deer, red-eared sliders, Mediterranean geckos, brown snakes (the ones that overran Guam), gulls, crows, European starlings, and so on.

    That is NOT the same cast that Dixon chose as the ancestors of the After Man fauna. He seems to have used size as the cutoff for who survived and who did not. If the past century is any guide, I think it’s very improbable that humans will wipe out deer and coyotes, for example.

    The really interesting thing is that every continent will start its post-human biotic evolution with many of the same players. Dogs, cats, rats, pigeons, and so on are globally distributed. How will these human-tolerant survivors evolve on each landmass once humans are gone?

    Eventually we came around to Pleistocene rewilding, but that’s a topic for another post (yours, or mine–let’s see who gets there first!).

    Great work as always. Congrats on your success as a ScienceBlogger. Keep ‘em coming.

  23. #23 Karl Zimmerman
    February 17, 2007

    Darren,

    Is that Gregory S. Paul article available anywhere besides a university (E.G., online somewhere?) I’d love to give it a gander.

  24. #24 TheBrummell
    February 18, 2007

    Thanks for posting this, Darren, it’s great fun to read about your two hypothetical worlds. I especially like the bit at the end of the description of slinkerworld about the Earth-Normal whales – marine giants and terrestrial midgets. By the way, in that world, could big-enough-to-clear-forests things like elephants get going, or is that a non-starter?

    Have you read Stephen Baxter’s Evolution? The last third or so of the book is post-human, so some of the same themes discussed here come out. Particularly regarding things that survive Homo sapiens.

  25. #25 Pavel Volkov
    February 19, 2007

    Dr Vector, have you read my “World tour to Neocene”? Click on the reference for it. Does Neocene world look like your suggestions?
    Sorry, but now in Neocene there are no Gambusia descendants. But the exploring is not terminated…

  26. #26 Sordes
    February 19, 2007

    Thank you for the links Pavel! One of them I already know from a forum about extinct animals. If I have time I will post something there.

  27. #27 Daniel Bensen
    February 22, 2007

    Wow. Hey! Hi! (waves) People are really interested in this stuff. It…well it sort of makes me want to get back in the game. Dare I email Dave??
    Damn, how do I get a closer look at that picture at the top of the page?
    Oh, and those lame birds…yeah they were talking about mine. I have no regrets!

  28. #28 Daniel Bensen
    February 23, 2007

    Hello again. Thank you all for providing me with the push I needed to get me back into the game.
    I’m back with Spec, now working on its new location to make sure the site is functional.
    It’ll be a little while before we’re ready to accept new content (we need to figure out a discussion forum and a way to get things added to the website without bogging down the webmasters), but soon we will welcome your ideas and input.
    The Speculative Dinosaur Project
    http://www.unet.univie.ac.at/~a0000265/Spec/

  29. #29 William Snyder
    September 8, 2007

    I think I will take on the Slinker World. When I have a site set up I will contact you. I already have many ideas for this project. Hopefully you will continue to contribute ideas to this.

  30. #30 Nentuaby
    December 4, 2007

    I can’t get enough of this stuff. :)

    My own personal passion in speculative zoology, though, isn’t alternative timelines but the future of our own.

    It’s definitely looking like any future xenopaleontologist who hits the planet in the year 10,000,000 or so is going to find an astonishingly sharp “Holocene Barrier”- all the megafauna and niche specialists going bye-bye at a pace Chixculub can only envy. But that’s happened a lot of times before- what kind of bizarre creatures might this hypothetical researcher’s zoologist colleagues find have evolved since?

    Personally, I’m rooting for the squid. ;)

  31. #31 Belaauquatica champlainiensis
    February 26, 2008

    I recently played “god” and i came up with “Lissamphibia world.”

    Reptiles go extinct in the Carboniferous, and amphibians inherit the earth. Then, to make things more demented, the continents never join and swamps reign for millions of years. Meanwhile, certain families evolve thicker (but scale-less) skin that allows them to survive in salt water and on land. When the continents finally split up, the southern continent is covered with swamps and the amphibians continue evolving. On the north continent, the swamps break up and grass evolves early. Certain salamanders evolve endothermy and become bipedal, dinosaur-esque predators while others evolve powerful hips that make them more like leopards. Huge herds of tank-like salamanders graze in the grass while a certain family of anuran evolves membranous wings and massive shoulder muscles to make them flight-capable. On the ground, in the scrub, a subfamily of amphiumas has adapted to live in burrows and jump out to grab small animals. Back in the south, the swamps are ruled by a 10-meter predatory caecilian, Venatagymnophionus maxiumus, which lurks in the swamps and beneath the peat to grab unwary surface dwellers. In the ocean, a massive descendent of the ancestral bullfrog preys on squid and fish, while its many relatives near the surface evolve high intelligence and sonar.

  32. #32 Russell J. Hawley
    December 12, 2008

    Another speculative biology project based on animals that must actually have existed is the mid-tertiary fauna of Antarctica. We’ve got a few bones of little early tertiary mammals (notoungulates and a polydolopoid marsupial) from the early Tertiary of Seymour Island, but palaeobotanical evidence obtained by drilling through the ice suggests that there were still Nothofagus forests in Antarctica until the Miocene. Surely the native Antarctic mammals continued to adapt and diversify. I picture big, sabre-toothed polydolopoids stalking herds of huge, shaggy ‘Woolly Notoungulates’ across the tundra…

  33. #33 D F Stuckey
    May 30, 2010

    Very nice summation of the seculative biology field – Was unaware of a few of those.

    Must point out unless it already has been, that Specworld links are no longer valid: Haven’t seen any news as to the status of this site, if. t’s moved or what has ahppened to it.

  34. #34 David Marjanović
    May 31, 2010

    Spec works, but many links haven’t been updated, so you’ll need to enter the logical names.

    Spec is also here, but I don’t know how complete that site is. It might be more up-to-date, and… the other site will probably expire on October 1st.

  35. #35 David Chenoweth
    September 27, 2010

    Speculative Biology is truly one of the few little pleasures that I have in life… I have loved Dinosaurs and Wildlife ever since the age of three. it was Dinosaurs the introduced me to the glories of Science, as I’m sure they were for the vast majority of other people who have an interest in the sciences. They are always on the top of my list when i look for the latest in science news. That said, I have for over 10 years now been creating an alien world based on an Earth like system. I call the world Varian III, and it is of interest to people in the storyline because of the amazing similarities to the formation of Earth and life on Earth. Though these similarities are striking, there are vast differences as well, Such as Vertebrate Tetrapods and Hexapods…. I’m no expert, and have had no proper training in any of the sciences required to do such a project correctly…. i strive for accuracy in my science, but I’m sure that I have failed in many ways.

    As a side note, I love Spec World, and would LOVE to see the rest of the pages finished. I think that it was well thought out and plained. I just wish I could find more such sites and more people like minded who enjoy this field of Science Speculation so I could bounce ideas off them and vice-a-versa… anyway, Love the site here as well, and will continue to visit as often as I can!

  36. #36 David Marjanović
    September 28, 2010

    I’ll get back to work on Spec as soon as possible… which might mean in November, might mean next year, might…

  37. #37 Vasika
    April 22, 2011

    [from Darren: sorry, delayed by spam filter]

    I like the speculative biology system so much, and all looks cool, and um, well,what can I say? I’ve created a littel world of my own, and it’s called, well, Isis, and since I was 12 or 13, for two years or three, it’s been going on around in my head.
    Okay, so the 1st two versions of Isis got screwed. Animals too big, plants not too diverse, not much niche partitioning, and I wasn’t a good artist, and nothing came out of it.
    Now’s Isis, of course, still exists in the form of two exercise books with drawings and descriptions, but I like it better.

    There are plants there, and they’re in a bit of competition with a set of beasts called terrestrocnidrians. I based em on coelentorates.
    Major photosynthesizers are gigantic phytozoans (hydrozoans, anthozoans analogues) which behave similarly, and form gigantic forests with plenty of variation across the planet’s two main continents. Plants are understorey things or form aquatic jungles and stuff.

    And the Northern landmass-
    the hotspot of biodiversity i concentrated on was a delta-like environment near a coast, like hell creek. Main lineage of carnivores were xenosauriformes.
    Based on theropods but with four arms evolved into powerful graspers like praying mantises, and same size ranges. Only jawed predators on Isis. No teeth, but have tooth plates like Dunkleostus, and similar to theropods, in that there are small, gliding tree-dwellers. Primitive forms exist with derived ones, and most of the derived ones live up north. Have large horns sometimes. Light armor on derived genera’s heads.
    Main megaherbivore is conetail titan, a creature wich uses a radula-like a snail. MOst animals have radulas or sucking disks to eat. Conetail guy lives on more open places. Has a huge skull to knock phytozoans down.
    Then, there are the suckers, qanimals like ornithopods. Live in huge herds, and biggest is megasuck; others live around too, with many niches, like herbivores, large herbivores and burrowers. The size and position of the lamprey-like or leech-like sucking disks are what give them the niches.Mostly plant-eaters, as they are lower to the ground.
    The megalocrawls are large, serpentine beasts with a powerful radula, which kill by poison. Largest are aquatic. Aquatic, actively swimming phytozoans live as fish in the rivers.
    The phytozoan branches of the northern hemisphere have very large communities of microfauna and smaller animals and epiphytes. There are even forests in the skies, almost, and the biggest phytozoans are 500 feet tall. Their skeletons are amde of a unique tissue called matrix-bone, which grows in interconnected ladder-like groups, housing polyps and chlorophyll.

    Southern landmass-
    A gigantic megacontinent, with no little islands around, separated from north by an inland sea. Smallish, basal, heavily-armored xenosauriformes exist here, but the main predators of the interior savanna and wetland hotspot, are the massive, filamented gorgons. These are giants with little intelligence and rely on mosquito-like mouthparts to kill.
    Main megaherbivores are walker phytozoans. These are siphonophore analogues, colonial animals with different purpose-built bodies.
    The walking beast which has the guts, reproductive organs and everything, are one animal, whereas the photosynthetic part on its back like a jungle, is another. These have large jaws and necks that determine ecological niches in the plains. Reach up to over 98 feet long.
    Then,there is a small number of suckers. Derived suckers don’t have any eyes whatsoever (eyed animals have compound eyes anyhow) and they’re perfectly built for walking on ONLY land (although they have many lines evolving) convergently)and the southern basals are actually leftovers from the time when suckers were quadrupeds. The trees harbor intersting communities of lemur-like animals (trees and phytozoans share space here).

    Gliding xenosauriformes of a specialized family descended from northen genera live in the mountain cloud-forests. Trees are the biggest photosynthesizers here. Air-dancers, dragonish-looking herbivores with sucking mouthparts and giant eyes, live everywhere. One kind of walker-phytozoan lives on the forest edges, and so do species of arboreal gorgons-like filamented, but more leopardish, or civet-ish). There are also specialized arboreal killers in the alps, the twisters. They look like snakes, but based on hemichordates. They’re the analogues of northern megalocrawls, with hte radula and extrme length and killing powerful.
    Radulophis gigas is the biggest, 35 feet long.
    Another queer variety of creatures are the splendid parafaeries. These flyers have large wingspans, and are vaguely mothh-like or human-like quadrupeds. Rest in trees.
    Vey light, they all use light gases in skin balloons to fly, and the wings work like pterosaurs. Largest is the goliath pixy, with a 45 foot wingspan. Human-like appearance is down to the strange-lloking face. Hunted by skyraptors, a very intelligent, genralized aerial hunter.

    Well, the wetlands are inhabited by nessie-like or pliosaur-like swmiinig phytozoans-a jellyfish analogue.

    Flyin g creatures are so big and odd here because of dense atmosphere. Planet is slightly larger than earth.

    Looks a bit too disjointed, huh?

  38. #38 Vasika
    April 23, 2011

    Yeah, I got up a polar continental set of island-like thingies a bit like super-sized indonesia, and the planet lacks ice caps. It’s a warm hothouse world. Anyhow, there’s polar forests and similarly southern-istic radiations of fauna, and TREE forests and things like terrestrial glass sponges.
    Not so well organized. That’s just WAY more disjointed!!

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