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Re: Kentrosaurus sexual dimorphism and Tarbosaurus juvenile skull



I guess Mike has out-brachiosaur-ed himself for the present LOL We
will need to wait a bit for the next brachiorrhea!

2011/5/14 Jaime Headden <qi_leong@hotmail.com>:
>
> Corrigenda renaming taxa have been in such fascinating things, notes of 
> significant specimens such as "SI" and "SII" being renumbered cannot be 
> considered less than earthshaking. Besides, you were very fun being all 
> self-effacing in the corrigendum.
>
> Not that I think it was necessary, though; you could simply have put that 
> into your next sauropod paper dealing with any brachiosaur that referenced 
> the specimens.
>
> Cheers,
>
> Jaime A. Headden
> The Bite Stuff (site v2)
> http://qilong.wordpress.com/
>
> "Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)
>
>
> "Ever since man first left his cave and met a stranger with a
> different language and a new way of looking at things, the human race
> has had a dream: to kill him, so we don't have to learn his language or
> his new way of looking at things." --- Zapp Brannigan (Beast With a Billion 
> Backs)
>
>
>
>
>
> ----------------------------------------
>> Date: Sat, 14 May 2011 09:20:25 +0100
>> From: mike@indexdata.com
>> To: turtlecroc@yahoo.com
>> CC: dinosaur@usc.edu
>> Subject: Re: Kentrosaurus sexual dimorphism and Tarbosaurus juvenile skull
>>
>> Yes, it's out, at least as regards being online:
>> http://www.informaworld.com/smpp/title~db=all~content=g937434119
>>
>> I have a paper in this issue so radical and wide-ranging in its
>> implications that it will shake the very foundations of evolutionary
>> theory. It's on page 727. I think we can all agree that this should
>> have been in Nature or Science.
>>
>> -- Mike.
>>
>>
>> On 13 May 2011 22:51, Paul P  wrote:
>> > Is the May JVP out yet? We don't have it online yet so I
>> > assume it isn't out in hardcopy yet either.
>> >
>> >
>> > --- On Mon, 5/9/11, bh480@scn.org  wrote:
>> >
>> >> From: bh480@scn.org
>> >> Subject: Kentrosaurus sexual dimorphism and Tarbosaurus juvenile skull
>> >> To: dinosaur@usc.edu
>> >> Date: Monday, May 9, 2011, 8:51 PM
>> >>
>> >> From: Ben Creisler
>> >> bh480@scn.org
>> >>
>> >>
>> >> In addition to the new dinosaurs Arcusaurus and Haya, the
>> >> May JVP has two
>> >> other dinosaur-related papers:
>> >>
>> >> I had an earlier posting on this one based on news stories
>> >> and press
>> >> releases:
>> >>
>> >> Takanobu Tsuihiji; Mahito Watabe; Khishigjav Tsogtbaatar;
>> >> Takehisa
>> >> Tsubamoto; Rinchen Barsbold; Shigeru Suzuki; Andrew H. Lee;
>> >> Ryan C.
>> >> Ridgely; Yasuhiro Kawahara; Lawrence M. Witmer
>> >> (2011)
>> >> Cranial osteology of a juvenile specimen of Tarbosaurus
>> >> bataar (Theropoda,
>> >> Tyrannosauridae) from the Nemegt Formation (Upper
>> >> Cretaceous) of Bugin
>> >> Tsav, Mongolia.
>> >> Journal of Vertebrate Paleontology 31(3): 497 - 517
>> >> DOI: 10.1080/02724634.2011.557116
>> >> http://www.informaworld.com/smpp/content~db=all~content=a937433397~frm=absli
>> >> nk
>> >>
>> >> A juvenile skull of the tyrannosaurid Tarbosaurus bataar
>> >> found in the Bugin
>> >> Tsav locality in the Mongolian Gobi Desert is described.
>> >> With a total
>> >> length of 290 mm, the present specimen represents one of
>> >> the smallest
>> >> skulls known for this species. Not surprisingly, it shows
>> >> various
>> >> characteristics common to juvenile tyrannosaurids, such as
>> >> the rostral
>> >> margin of the maxillary fenestra not reaching that of the
>> >> external
>> >> antorbital fenestra and the postorbital lacking the cornual
>> >> process. The
>> >> nasal bears a small lacrimal process, which disappears in
>> >> adults. Lacking
>> >> some of the morphological characteristics that are adapted
>> >> for bearing
>> >> great feeding forces in adult individuals, this juvenile
>> >> specimen suggests
>> >> that T. bataar would have changed its dietary niches during
>> >> ontogeny. The
>> >> numbers of alveoli in the maxilla (13) and dentary (14 and
>> >> 15) are the same
>> >> a
>> > etically in
>> >> T. bataar and thus are not consistent with the hypothesis
>> >> that the numbers
>> >> of alveoli decreases ontogenetically in tyrannosaurids.
>> >>
>> >>
>> >> Holly E. Barden & Susannah C. R. Maidment (2011)
>> >> Evidence for sexual dimorphism in the stegosaurian dinosaur
>> >> Kentrosaurus
>> >> aethiopicus from the Upper Jurassic of Tanzania.
>> >> Journal of Vertebrate Paleontology 31(3): 641--651
>> >> DOI: 10.1080/02724634.2011.557112
>> >> http://www.informaworld.com/smpp/content~db=all~content=a937432642~frm=title
>> >> link
>> >>
>> >> Sexual dimorphism, the condition whereby males and females
>> >> differ from one
>> >> another physically, is one of the most fundamental aspects
>> >> of the biology
>> >> of any animal. However, sexually dimorphic characters can
>> >> be subtle and are
>> >> mainly related to soft tissue anatomy. They are, therefore,
>> >> difficult to
>> >> identify reliably in the fossil record particularly when
>> >> dealing with small
>> >> sample sizes and osteology alone. The first geometric
>> >> morphometric analysis
>> >> of dimorphism in a thyreophoran (armored) dinosaur shows
>> >> that the femora of
>> >> the stegosaurian dinosaur Kentrosaurus aethiopicus (Upper
>> >> Jurassic,
>> >> Tanzania) bear a statistically significant shape difference
>> >> of the proximal
>> >> end, which is independent of size and is therefore proposed
>> >> to be a sexual
>> >> difference. Although the disarticulated nature of the
>> >> material means that
>> >> intraspecific variation in other skeletal elements, such as
>> >> the enigmatic
>> >> dermal armor, cannot be identified as sexual dimorphism at
>> >> this time, this
>> >> study provides a methodology for further work on
>> >> articulated stegosaurian
>> >> specimens and has the potential to reveal additional
>> >> information regarding
>> >> the palaeobiology and population dynamics of this poorly
>> >> understood clade.
>> >>
>> >>
>> >> --------------------------------------------------------------------
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>> >>
>> >
>> >
>
>