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Thursday, 28 March 2013

Book news for Easter: more from Daisy and the Isle of Wight Dragon, and exciting plans for Pterosaurs

Two bits of good news, everyone! You can now purchase Martin Simpson's Daisy and the Isle of Wight Dragon, which I co-illustrated, direct from Amazon  for a mere £5. To celebrate, here's an vaguely Easter-themed illustration I contributed to the book, depicting a Vectidraco hatching from a typically soft-shelled pterosaur egg. I'm sure hatchling pterosaurs would be adorable little urchins that we'd feature in innumerable YouTube videos if they were alive today, but perhaps only once they'd dried out from hatching. Like freshly-emergent bird chicks, baby pterosaurs were probably initially covered in goopy, matted integuments and would look pretty skanky (as in the image above, then). For the nerdy among you, I used the hatching body mass regressions detailed in Lü et al. (2011) to work out the likely mass of a Vectidraco hatchling to get an idea of its size and proportions. The reported wingspan estimate for an adult Vectidraco by Naish et al. (2013) is 0.75 m, which translates to a freshly-laid egg mass of 10 g, an egg mass of 16.25 g at the end of the incubation period, and a hatchling mass of 7.25 g. To put that into perspective, Vectidraco hatchlings would have tiny wingspans of 18-19 cm, and would probably neatly fit inside your loosely-closed hand.

The second bit of good news is that Princeton University Press and I have been putting our heads together to plan some launch events for my own book, Pterosaurs (preorders being taken here). They're still at very early stages and we cannot say anything concrete about them yet, but there are plans to bring some leathery-winged goodness to the Internet, and parts of the UK, this July. Further updates as they come in. Enjoy the Easter weekend, all!

  • Lü, J., Unwin, D. M., Deeming, C., Jin, X., Liu, Y. and Ji, Q. 2011. An egg-adult association, gender, and reproduction in pterosaurs. Science, 331, 321-324.
  • Naish, D., Simpson, M. I. & Dyke, G. J. 2013. A new small-bodied azhdarchoid pterosaur from the Lower Cretaceous of England and its implications for pterosaur anatomy, diversity and phylogeny. PLoS ONE 8(3): e58451. doi:10.1371/journal.pone.0058451


  1. Wait. "... which translates to a freshly-laid egg mass of 10 g, an egg mass of 16.25 g at the end of the incubation period."

    You're saying that eggs increase their mass by 62.5% after laying?!

    1. Yup. Because pterosaur eggs had soft, thin shells, they could probably take up water from their surroundings rather than relying on an on-board water store, à la dinosaur eggs. The result, as you may expect, is a considerable increase in egg mass post oviposition. The calculations here are derived from mass models for modern squamate eggs.

    2. Huh! Live and learn!

      So birds' eggs don't do this?

    3. Bird eggs lose a little mass through water evaporation, but not much - around 10% or so, but it's variable between species. I'm pretty sure that no bird eggs increase in mass, though.