Re: Skull ornamentation in juvenile Pachycephalosaurus fossils from Upper Cretaceous Hell Creek Formation

[Paul P <turtlecroc@yahoo.com>]

That link doesn't work [either].


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On Sun, 2/7/16, Ben Creisler <bcreisler@gmail.com> wrote:

 Subject: Re: Skull ornamentation in juvenile Pachycephalosaurus fossils from 
Upper Cretaceous Hell Creek Formation
 To: dinosaur@usc.edu
 Date: Sunday, February 7, 2016, 12:31 AM
 
 Sorry. Same fix to this
 ref to prevent the url rewrite and redirect:
 
 Mark B. Goodwin & David C.
 Evans (2016)
 The early expression of
 squamosal horns and parietal ornamentation
 confirmed by new end-stage juvenile
 Pachycephalosaurus fossils from
 the Upper
 Cretaceous Hell Creek Formation, Montana.
 Journal of Vertebrate Paleontology (advance
 online publication)
 DOI:
 10.1080/02724634.2016.1078343
 http: //
 www.tandfonline.com/doi/full/10.1080/02724634.2016.1078343
 
 On Sat, Feb 6, 2016 at 10:27
 PM, Ben Creisler <bcreisler@gmail.com>
 wrote:
 > Ben Creisler
 > bcreisler@gmail.com
 >
 >
 >
 A new paper:
 >
 >
 > Mark B. Goodwin & David C. Evans
 (2016)
 > The early expression of
 squamosal horns and parietal ornamentation
 > confirmed by new end-stage juvenile
 Pachycephalosaurus fossils from
 > the
 Upper Cretaceous Hell Creek Formation, Montana.
 > Journal of Vertebrate Paleontology
 (advance online publication)
 > DOI:
 10.1080/02724634.2016.1078343
 > https://urldefense.proofpoint.com/v2/url?u=http-3A__&d=CwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=x82f3Wlkwtmbr1z8IAt9jA&m=nA9RsiTGGbkmKz3MgOz4zb3aTfEXNvTjwal-fmC3xhQ&s=m7KNFKuqoulZyFw_kfHXgWHQMo9SOe-4mcEOtnfta04&e=
 
 www.tandfonline.com/doi/full/10.1080/02724634.2016.1078343
 >
 > New end-stage
 juvenile specimens of Pachycephalosaurus from the Upper
 > Cretaceous Hell Creek Formation, Montana,
 confirm the earliest
 > expression of
 squamosal nodes, parietal ornamentation, and jugal
 > morphology in the smallest and presumably
 youngest individuals yet
 > known.
 High-resolution computed tomography of the slightly
 thickened,
 > undomed parietal reveals a
 dense cortex, a highly cancellous interior
 > of irregularly shaped erosion cavities,
 and bony trabeculae indicative
 > of
 primary, fast growing bone. The parietal, with its highly
 > ornamented septum morphology and patent
 sutures, is nearly identical
 > to the
 holotype of ‘Dracorex hogwartsia,’ and combined with
 these new
 > internal histological
 details, supports the alternative interpretation
 > that ‘D. hogwartsia’ is a juvenile
 Pachycephalosaurus wyomingensis.
 > The
 squamosal nodes grow into an array of horns and secondary
 nodes
 > exemplified by the
 pachycephalosaurin ‘Stygimoloch spinifer’
 > considered in this study to be a subadult
 P. wyomingensis. Unlike the
 > squamosal
 ornamentation, the hypertrophied midline row of parietal
 > nodes is transient as the frontoparietal
 dome expands later in
 > ontogeny. We
 propose the term ‘ontogimorph’ as a substitute for
 > ‘semaphoront’ to describe these
 taxon-specific morphological variants
 >
 that grow allometrically and express extreme cranial
 morphology along
 > a postnatal growth
 continuum ontogenetically. These juvenile-,
 > sub-adult-, and adult-specific features in
 the skull of
 > Pachycephalosaurus may
 have allowed the visual identification of
 > ontogimorphs and signal their changing
 sociobiological status.