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[dinosaur] Flying lizards + captorhinid evolutionary history (free pdfs)





Ben Creisler
bcreisler@gmail.com


Two recent non-dino papers with free pdfs:


J. Maximilian Dehling (2017)
How lizards fly: A novel type of wing in animals.
PLoS ONE 12(12): e0189573.Â
doi: https://doi.org/10.1371/journal.pone.0189573
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0189573



Flying lizards of the genus Draco are renowned for their gliding ability, using an aerofoil formed by winglike patagial membranes and supported by elongated thoracic ribs. It remains unknown, however, how these lizards manoeuvre during flight. Here, I present the results of a study on the aerial behaviour of Dussumier's Flying Lizard (Draco dussumieri) and show that Draco attaches the forelimbs to the leading edge of the patagium while airborne, forming a hitherto unknown type of composite wing. The attachment of the forelimbs to the patagium suggests that that aerofoil is controlled through movements of the forelimbs. One major advantage for the lizards is that the forelimbs retain their complete range of movement and functionality for climbing and running when not used as a part of the wing. These findings not only shed a new light on the flight of Draco but also have implications for the interpretation of gliding performance in fossil species.


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Marco Romano, Neil Brocklehurst & JÃrg FrÃbisch (2017)
Discrete and continuous character-based disparity analyses converge to the same macroevolutionary signal: a case study from captorhinids.
Scientific Reports 7, Article number: 17531 (2017)
doi:10.1038/s41598-017-17757-5
https://www.nature.com/articles/s41598-017-17757-5
https://www.nature.com/articles/s41598-017-17757-5.pdf


The relationship between diversity and disparity during the evolutionary history of a clade provides unique insights into evolutionary radiations and the biological response to bottlenecks and to extinctions. Here we present the first comprehensive comparison of diversity and disparity of captorhinids, a group of basal amniotes that is important for understanding the early evolution of high-fiber herbivory. A new fully resolved phylogeny is presented, obtained by the inclusion of 31 morphometric characters. The new dataset is used to calculate diversity and disparity through the evolutionary history of the clade, using both discrete and continuous characters. Captorhinids do not show a decoupling between diversity and disparity, and are characterized by a rather symmetric disparity distribution, with a peak in occupied morphospace at about the midpoint of the cladeâs evolutionary history (Kungurian). This peak represents a delayed adaptive radiation, identified by the first appearance of several high-fiber herbivores in the clade, along with numerous omnivorous taxa. The discrete characters and continuous morphometric characters indicate the same disparity trends. Therefore, we argue that in the absence of one of these two possible proxies, the disparity obtained from just one source can be considered robust and representative of a general disparity pattern.



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