Extant vs Extinct

One significantly underappreciated aspect of palaeontological research is just how hard it can be to make reasonable statements about extinct animals in comparison to, or in analogy to living animals. Not for the obvious reason that fossils (of vertebrates at least) are generally just collections of bones (and often not even much of a skeleton) with the occasional splatter of half preserved skin but for the fact that often we can say a lot about an extinct organism, but not much about living ones.

The short version of that is that we actually know far more about many extinct species than extant ones. It’s all very well producing a huge monograph of some fossil lizard that has a close relative among the living, but then you can be frustrated by a lack of a similar level of detail in the live animal. This is, I image, due to two different but related reasons.

Firstly the average biological researcher presented with a livign animal (new to science or one that has known for centuries) has a huge wealth of things he can study – development, soft tissues, behaviour, genetics, natural variation and sexual dimorphism, bony anaomy, biogeography, evolutionary relationships, physiology, ecology and more. In contrast most vertebrate palaeontologists at least dabble in systematics, taxonomy and anatomical descriptions and a great many base their research around it and in consequence do it in far greater detail and is only therefore are able to make only superficial comparisons in terms of something like the shape of the femur because the biologists never got around to describing it in as detailed a manner.

Secondly, while there are obviously far more biologists than palaeontologists out there, they also have a hell of a lot more species to work on. I know a couple of entomologists and I can barely understand how they even vaguely keep track of things. Some small *families* of beetles have thousands of species in them and I can’t keep all of the theropods straight in my head. It should not be a surprise then that archosaur workers have described some fossil birds say in more detail than have the ornithologists who have 10 000+ species to work on, not a few hundred.

9 Responses to “Extant vs Extinct”


  1. 1 Roger 26/04/2009 at 8:32 pm

    This is something I’ve often lamented! I was listening to The Science Show on ABC Radio National(which, by the way, is excellent—you can podcast it from abc.net.au/rn) where they were interviewing a beetle taxonomist in the USA. His estimate was that there were half a million beetle species described, and probably three times that many yet to be described. Who knows how they keep up.

    I think the solution is to just give up on palaeontology and become a neontologist :)

  2. 2 David Hone 26/04/2009 at 8:58 pm

    And don’tforget thatmany invertebrate desciptions are(or at least were when I used to look at them just a few years ago) often limited to a paragraph or even a few lines. You would get things like “A member of genus X with all the apomophies of that genus but can be distinguished by the presence of elongate antennae. New name in Y, holotype and paratypes at museum Z, found in Kenya”. I have seen descriptions from this as recently as the 90’s. That is ALL you get! I know how much they have to get through, but it leaves a bit to be desired in terms of depth…

  3. 3 Jura 26/04/2009 at 11:17 pm

    I remember reading Romer’s lament of this fact in Osteology of the Reptiles; and that was almost 60 years ago!

    This is, no doubt, one of the reasons why many paleontologists spend a lot of time working with extant animals.

  4. 4 Andy 27/04/2009 at 12:12 am

    An important side effect of this, of course, is that it is necessary to really do one’s homework in order to make truly meaningful functional inferences. I get a little frustrated at times seeing the way that sexy new techniques (e.g., FEM, bite force calculations, etc.) have been applied to dinosaurs and other charismatic extinct megafauna without the intermediate step of understanding if the analysis even works in modern animals (or for that matter, even understanding the full benefits and limitations of these techniques). Fortunately, this is beginning to change (slowly) for FEM, but I suspect we’ll see this repeated all over again with the next Analysis Du Jour.

    • 5 Nick Gardner 28/04/2009 at 11:55 pm

      John Hutchinson’s latest paper touches on some of these matters in a very relevant way, see http://whyihatetheropods.blogspot.com/2009/04/fossil-and-living-theropods-false.html

      “”””For example, studies such as Gatesy (1990) and Dial (2003a) exemplify how the gulf between neontology and palaeontology is vanishing, and none too soon. No longer are technological tools limiting the kinds of questions that can be asked— with advances in 3D imaging, computer modelling and simulation, phylogenetics and biomechanical analysis, [..] We urge that researchers in this area take up the challenge to dismantle disciplinary walls between experimental and theoretical, anatomical and biomechanical, neontological and palaeontological and other false dichotomies. It is with the collapse of these artificial barriers that a new synthesis should dawn: one in which new discoveries, fossil or experimental become quickly integrated into a richer portrait of the history and
      mechanisms of theropod locomotion. [...] The onus is on palaeobiology researchers to extend their expertise into this domain and vice versa; the life sciences as a whole will benefit.””””

  5. 6 David Hone 01/05/2009 at 9:34 am

    I’m finally back from the filed and can reply again, my last one got lost in the ether. Jura: I was thinking of / inspired by Romer at least in part on this post, but the issue is true well beyond reptiles and across animals in general I think, and quite possibly plants too in soem cases.

    Nick, you had beaten me to it. I had mentioned John Hutchinson and also Don Henderson as specific examples as people who really do ‘ground-truth’ their methods by comparing them to / testing them on extant organisms as well as extinct ones which fits with Andy’s point. This IS an issue – unverified methods, but things are getting better and we will see much improvement in this soon as long as people don’t go overboard and change to another methodology first…

  6. 7 Big poppa 11/05/2012 at 12:54 am

    …you misspelled living


  1. 1 Species recognition and pheasants « Dave Hone’s Archosaur Musings Trackback on 08/12/2009 at 9:05 am
  2. 2 Osteological correlates « Dave Hone’s Archosaur Musings Trackback on 22/01/2010 at 8:36 am

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