The missing tail of Pteranodon

I have commented on this before, but the occasional use of ‘long’ and ‘short’ tailed to describe the rhamphorhynchoids and pterodactyloid pterosaurs respectively does not fit very well. In the case of the former, it’s the anurognathids that cause the problems, and with the latter it is Pteranodon. This is something I will come back to in another pterosaur post in preparation, but it is interesting how some ideas never get overturned in the public mind (and even of some experts) even when the results are pretty clear, unambiguous, and have been published prominently and referred to infrequently.

In this case, Chris Bennett first described the elongate tail way back in 1987. His figure was reproduced both in Peter Wellnhofer’s stellar (and very much used by experts and the public alike) ‘Encyclopaedia of Pterosaurs’ in 1991 (now sadly and bizarrely out of print in English and German, but available in an updated version in Spanish I understand). Chris again covered it in his monstrous and phenomenally detailed monograph on Pteranodon in 2001. In short, it’s been covered scientifically in detail, and in perhaps the most prominent (admittedly of a very low number) of public books on pterosaurs. Why then have so few people realised that this is the case? I rarely see it mentioned when non-pterosaur experts refer to Pteranodon, and much artwork and reconstructions seem to miss it when by now it has been doing the rounds for over 20 years.

pteranodon-tail

Here is that figure (courtesy of Chris) to show you how the tail is structured, with a bunch of normal vertebrate at the base (on the left) and then the caudal ‘rod’ as it has become known (A is in dorsal view, i.e. from above, B from the left side). This was originally thought to be some form of caudal projection for the rear vertebrae, but now appears to be instead a series of small fused vertebrae with a groove down the middle apparently part of the neural arch. It should be noted that this information comes not from a single specimen, but information combined from several each of which preserved varying sections but sufficient to put this together. I would like to add at this point that Chris is famous for having seen pretty much every specimen of Pteranodon ever in museum collections, currently clocking in at over 1200 by his count. OK, some of these are just single partial bones, but it should give you an idea of just how much he knows about Pteranodon. If he says the tail looks like this, I’m happy to take his word for it.

The next point to make is that while I am calling this a ‘long’ tail, it is still really pretty short by pterosaur standards, even compared to some other pterodactyloids. Chris estimated that the tail (including the rod) was about in length about 3.5% of the wingspan of the animal. For a large Pteranodon, say around 7 m across, the tail would be still only around 25 cm. Small yes, but much longer than many would have considered, and indeed seem to.

4 Responses to “The missing tail of Pteranodon”


  1. 1 Christopher Collinson 06/04/2009 at 9:22 pm

    Codorniú reconstructs the tail of Pterodaustro to at least 22 caudals based on several juvenile specimens. And NSM-VP 19892 holotype of Anhanguera piscator preserves 11 caudals. In both cases the tails were probably somewhat longer as no obvious terminal cadual is preserved.

  2. 2 Rutger 06/04/2009 at 11:57 pm

    What does this mean in tail vertebrae count? I think that is a better indication for tail length, rather than the relative measurement of its proportion to wingspan.

  3. 3 David Hone 07/04/2009 at 8:02 am

    Rutger: Well as for a vertebral count in Pteranodon, it’s pretty much impossible to say, the rods appear to be so fully sutured that even if you cut them apart I doubt you would be able to find the original joints and make a count. As I say this reconstruction is based on a number of tails in any case so we’d probably only have a rough estimate and not an absolute count.

    The point about the proportion to wing length was really to show that it is still not a huge tail. In the circumstyances it’s actually not a bad estimate since a) we can’t count the vertebrae, and b) pterosaurs are very conservative, so you can make a decent guess at the tail length of a Pteranodon even without a preserved tail.

    Chris: I made a point of counting and measing Anhanguera when in Tokyo hence my comment about longer ones in other pterodactyloids. It’s true that distal caudals are rarely preserved and it’s hard to tell quite where they might have ended, though obviously they tend to taper so while one or even five cuadla might be missing they were probably very small and would make little difference to the total length of the tail provided you already have a fairly complete one. The rod of Pterandond does show that we can make a dramtic underestimation however if we miss soemthing like this, it pretty much doubles the tail length.

  4. 4 helderdarocha 15/04/2013 at 3:51 pm

    Hi David. I am making a Tupuxuara skeleton out of foam (http://imaginosaurus.wordpress.com). It’s almost finished but it lacks some parts such as fingers, feet, and a tail, since I was unable to find fossil images or even diagrams with reliable information on these bones. I am probably going to model the tail from Pteranodon (but nor really sure if I will use those last two long vertebrae.) Do you know of any images or diagrams showing the tail of a Tupuxuara or more closely related pterosaur?


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