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Fw: Pterosaurs as basal archosauriforms




Resend


This should spark the interest of a certain pterosaur blogger. I don't have 
access to the early editions of Historical Biology so I only have the abstract 
to go on, but it sounds like Bennett got some neat results. Under Bennett's 
definition of Ornithodira (dinos + pterosaurs), that would mean pseudosuchians 
are now ornithodirans, which is weirder still given Nesbitt's recent 
reevaluation suggesting dinosaurs are crurotarsans. I feel like the house of 
cards has started tumbling down.

Jason


>> From: Ben Creisler <bcreisler@gmail.com>
>>To: dinosaur@usc.edu 
>>Sent: Monday, 24 September 2012 11:37 AM
>>Subject: Pterosaurs as basal archosauriforms
>> 
>>From: Ben Creisler
>>bcreisler@gmail.com
>>
>>A new online paper:
>>
>>
>>S. Christopher Bennett (2012)
>>The phylogenetic position of the Pterosauria within the
>>Archosauromorpha re-examined.
>>Historical Biology (advance online publication)
>>DOI:10.1080/08912963.2012.725727
>>http://www.tandfonline.com/doi/full/10.1080/08912963.2012.725727
>>
>>
>>A previous analysis of the phylogenetic position of the Pterosauria
>>argued that pterosaurs were not closely related to dinosaurs as is
>>generally accepted, but rather were outside the crown group
>>Archosauria. However, that study was dismissed for the use of
>>inappropriate methods. Here, the data set from that analysis was
>>divided into five partitions: one with characters associated with
>>cursorial digitigrade bipedal locomotion and
the other four with
>>characters from the skull and mandible, postcranial axial skeleton,
>>forelimb and hindlimb, respectively. The partitions were subjected to
>>homogeneity testing, and the Cursorial partition was found to be
>>incongruent with other partitions and all other characters at the α =
>>0.01 probability level. Deletion of the Pterosauria removed all
>>significant incongruence, demonstrating that the incongruence results
>>from the coding of pterosaurs for the cursorial characters. The cause
>>of the incongruence was interpreted as homoplasy in hindlimb
>
aluating and reformulating the characters
>>of the Cursorial partition, the revised data set was tested for
>>homogeneity and no significant incongruence was found. Lastly, the
>>data set was updated with additional characters and taxa from recent
>>analyses, tested as before, and when analysed suggested that the
>>Pterosauria were basal
archosauriforms well outside the crown group
>>Archosauria.
>>
>>
>>
>
>