• Tag Archives pterosaurs
  • New paper on the strangest pterosaur ever.

    Ooh, I’m coming in under the wire this time (see the time stamp).

    So when someone talks about pterosaurs, or flying reptiles, you probably think of something like one of these:

    PteranodonRhamphorhynchus

    Pteranodon and Rhamphorhynchus. The two archetypes of pop culture pterosaurs.
    Former image from here. Latter image by Charlie McGrady.

     

    Few folks would normally think of this as a normal pterosaur:

    Pterodaustro

    Pterodaustro guinazui (pic culled from Wikipedian artist: Arthur Weasley).

     

    Its name was Pterodaustro guinazui, and unlike other pterosaurs, which fed on fish, insects, or other types of meat, P. guinazui was a filter feeder. It has commonly been compared to a Mesozoic flamingo (thus resulting in more than a fair share of flamingo like drawings). It sifted microorganisms from the waters that it lived near. Unlike today’s modern flamingo (Phoenicopterus), Pterodaustro could filter feed without dipping its head upside down. As far as pterosaurs go, it was certainly one of (if not) the strangest species to have come from this group.As is typical with the weird ones, though they are celebrated for their uniqueness; that is about all that is known about them.

    Well, no more:

    Chinsamy, A., Codorni?, L., Chiappe, L. 2008. Developmental growth patterns of the filter-feeder pterosaur, Pterodaustro guinazui. Biology Letters. DOI: 10.1098/rsbl.2008.0004 (online: first cite)

    Abstract
    Life-history parameters of pterosaurs such as growth and ontogenetic development represent an enigma. This aspect of pterosaur biology has remained perplexing because few pterosaur taxa are represented by complete ontogenetic series. Of these, Pterodaustro is unique in that besides being represented by hundreds of individuals with wing spans ranging from 0.3 to 2.5m, it includes an embryo within an egg. Here we present a comprehensive osteohistological assessment of multiple skeletal elements of a range of ontogenetic sizes of Pterodaustro, and we provide unparalleled insight into its growth dynamics. We show that, upon hatching, Pterodaustro juveniles grew rapidly for approximately 2 years until they reached approximately 53% of their mature body size, whereupon they attained sexual maturity. Thereafter, growth continued for at least another 3–4 years at comparatively slower rates until larger adult body sizes were attained. Our analysis further provides definitive evidence that Pterodaustro had a determinate growth strategy.

    Pterodaustro skull

    Pterodaustro guinazui skull (photo from: http://www.pterosaurier.de)

     

    I have yet to read the full paper, but from what it says here, it would appear that the filter feeding lifestyle took its toll on P. guinazui, as its growth rate was remarkably slow. As this is the first time a growth series has been done on a pterosaur, it probably shouldn’t be assumed that this growth was typical of all pterosaurs (which would have had diets that were much higher in protein, thus aiding growth). Still the results are definitely interesting. Plus any new bits of info on the world’s strangest pterosaur, is a good thing in my book.

    ~Jura


  • The Hummingbird of Pterosaurs.

    Nemicolopterus

    Just announced today in the journal PNAS, is the discovery of the world’s smallest pterosaur. Dubbed: Nemicolopterus crypticus, this little guy had a wingspan of only 10 inches (25.4 cm). I haven’t had a chance to read the paper on it yet, but from the abstract, it appears to be a juvenile. I’d like to know how much larger the authours believe N.crypticus got.

    Either way, this is big news for pterosaur researchers. It means that either:

    • A.) Pterosaurs covered a greater size range than previously thought, or…
    • B.) Pterosaur juveniles lived in different niches than adults.

    Given the reptilian status of pterosaurs, I wouldn’t be surprised if it did turn out to be choice B. The large size discrepancy between adults and hatchlings / juveniles, often results in the formation of two size classes per species. This allows the animals to better exploit their given ecosystems.

    Anyway, we’ll just have to wait for the paper, and see what the results suggest.

    Still, it’s a mighty neat find.

    ~Jura