[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Cassowary (theropod) headgear (cassowary casque) (free pdf)



Ben Creisler
bcreisler@gmail.com


Note that Darren Naish has made the pdf available for free at this link:


https://darrennaish.files.wordpress.com/2014/11/naish-perron-2014-cassowary-casque-history-biology-evolution.pdf

On Thu, Nov 27, 2014 at 10:41 AM, Ben Creisler <bcreisler@gmail.com> wrote:
> Ben Creisler
> bcreisler@gmail.com
>
>
> Just in time for American Thanksgiving, a paper about a giant living
> bird. And just think--if Columbus had landed in New Guinea, we'd be
> eating cassowaries today....and REAL yams (not sweet potatoes labeled
> as "yams").
>
>
>
> Darren Naish & Richard Perron (2014)
> Structure and function of the cassowary's casque and its implications
> for cassowary history, biology and evolution.
> Historical Biology (advance online publication)
> DOI:10.1080/08912963.2014.985669
> http://www.tandfonline.com/doi/full/10.1080/08912963.2014.985669#.VHdmOzHF_To
>
> Cassowaries (Casuarius) possess a cranial casque, sheathed by keratin
> and composed of modified cranial bones. We combine data and hypotheses
> on three areas of cassowary research. First, we present novel
> observations on casque anatomy. The bony core is fragile,
> incorporating a mass of trabeculae anteriorly and an empty space
> posteriorly. Secondly, we use these observations to evaluate
> hypotheses of casque function. Implications that the casque evolved
> within the context of activities involving percussive actions are
> unlikely and observations that might support these hypotheses are
> absent. It is most likely that the casque serves a sociosexual role
> and functions in visual and acoustic display. The similarity in casque
> form between males and females, combined with male parental
> investment, makes it plausible that the extravagant structures present
> in cassowaries evolved within the context of mutual sexual selection.
> Thirdly, we combine morphological, molecular and geological evidence
> to provide a new phylogenetic history for cassowaries. We suggest that
> cassowaries invaded New Guinea in at least two waves and provisionally
> regard crown–cassowaries as a geologically young, post-Pliocene clade.
> We provide these hypotheses as areas requiring discussion and urge
> other workers to test our ideas with new data on cassowary anatomy,
> behaviour and genetics.