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RE: Spinosaurus redescribed as giant semiaquatic theropod



Yes, I was wondering what people meant by that, too. The thickened limb bones 
might function as ballast, but not a sail.

Thomas R. Holtz, Jr.
Email: tholtz@umd.edu   Phone: 301-405-4084
Office: Centreville 1216                        
Senior Lecturer, Vertebrate Paleontology
Dept. of Geology, University of Maryland
http://www.geol.umd.edu/~tholtz/
Fax: 301-314-9661               

Faculty Director, Science & Global Change Program, College Park Scholars
http://www.geol.umd.edu/sgc
Fax: 301-314-9843

Mailing Address:        Thomas R. Holtz, Jr.
                        Department of Geology
                        Building 237, Room 1117
                        University of Maryland
                        College Park, MD 20742 USA

> -----Original Message-----
> From: owner-DINOSAUR@usc.edu [mailto:owner-DINOSAUR@usc.edu] On Behalf Of 
> mmiller2003@comcast.net
> Sent: Monday, September 15, 2014 9:37 AM
> To: bcreisler@gmail.com
> Cc: dinosaur@usc.edu
> Subject: Re: Spinosaurus redescribed as giant semiaquatic theropod
> 
> I would appreciate some help understanding a point:
> At different times in the many emails regarding Spinosaurus, a statement was 
> made about the sail acting as ballast.  As a sailor, 
on a
> boat ballast is put as low as it can be secured, and always below the 
> waterline.  The sail on a boat, sticking up into the air, is
anything
> but ballast, and in a breeze contributes strongly to the boat tipping 
> sideways.  The purpose of the ballast is to counteract
this.  So,
> question: how is "ballast" being used in the context of Spinosaurus?  And if 
> used to mean the same as for sailboats, how would it
> function as a stabilizer homologous to a sailboat's ballast when it is above 
> the center of mass of the creature, regardless of how
much
> of it is below water and how much above?
> Thanks in advance
> Michael
> 
> ----- Original Message -----
> 
> 
> 
> ----- Original Message -----
> 
> From: "Ben Creisler" <bcreisler@gmail.com>
> To: dinosaur@usc.edu
> Sent: Sunday, September 14, 2014 7:13:54 PM
> Subject: Re: Spinosaurus redescribed as giant semiaquatic theropod
> 
> Ben Creisler
> bcreisler@gmail.com
> 
> And more...
> 
> 
> Scott Hartman's critiques continue...
> 
> Part 2
> http://www.skeletaldrawing.com/home/there-may-be-more-fishiness-in-spinosaurus9132014
> 
> Part 1
> http://www.skeletaldrawing.com/home/theres-something-fishy-about-spinosaurus9112014
> 
> ***
> Luis Rey updates Spinosaurus
> 
> http://luisvrey.wordpress.com/2014/09/14/what-happems-when-spinosaurus-runs-ashore/
> 
> 
> 
> On Sat, Sep 13, 2014 at 8:50 AM, Ben Creisler <bcreisler@gmail.com> wrote:
> > Ben Creisler
> > bcreisler@gmail.com
> >
> > News and blog stuff not yet mentioned (the "Spinosaurnado" continues!):
> >
> >
> > National Geographic photo gallery
> >
> > http://ngm.nationalgeographic.com/2014/10/spinosaurus/hettwer-photogra
> > phy
> >
> > ===
> >
> > The Hunt for Spinosaurus (news story with photo gallery)
> >
> > http://www.washingtonpost.com/news/speaking-of-science/wp/2014/09/11/t
> > he-hunt-for-spinosaurus/
> >
> >
> > ===
> >
> > http://www.smithsonianmag.com/science-nature/meet-mighty-spinosaurus-f
> > irst-swimming-dinosaur-180952679/?no-ist
> >
> > ====
> >
> > BLOGS
> >
> > Includes additional artwork for skull and tail
> >
> > http://novataxa.blogspot.com/2014/09/spinosaurus.html
> >
> > ===
> > Andea Cau Theropoda blog (in Italian with rough English translation
> > option)
> >
> > http://theropoda.blogspot.com/2014/09/spinosaurus-revolution-episodio-
> > ii-ode.html?spref=tw
> >
> >
> > Addresses  "disproportionately"  of pelvic region and limbs compared
> > to the size of the vertebrae
> >
> > ===
> > Luis Alcalá blog (in Spanish)
> >
> > http://www.elmundo.es/blogs/elmundo/blogosaurio/2014/09/11/el-dinosaur
> > io-acuatico.html
> >
> >
> > On Fri, Sep 12, 2014 at 7:16 PM, Ben Creisler <bcreisler@gmail.com> wrote:
> >> Ben Creisler
> >> bcreisler@gmail.com
> >>
> >> Blogs and news...
> >>
> >>
> >> Spinosaurus exhibit inside look
> >>
> >> http://dinosours.wordpress.com/2014/09/12/spinosaurus-at-the-national
> >> -geographic-museum/
> >>
> >> Blogs
> >>
> >> http://qilong.wordpress.com/2014/09/12/the-outlaw-spino-saurus/
> >>
> >>
> >> http://theropoddatabase.blogspot.com/
> >>
> >> ***
> >> Nizar Ibrahim
> >>
> >> http://news.nationalgeographic.com/news/2014/09/140912-emerging-explo
> >> rer-nizar-ibrahim-paleontology-sahara-dinosaur-fossil/
> >>
> >> On Thu, Sep 11, 2014 at 11:32 AM, Ben Creisler <bcreisler@gmail.com> wrote:
> >>> News stories
> >>>
> >>> http://press.nationalgeographic.com/2014/09/11/scientists-report-fir
> >>> st-semiaquatic-dinosaur-spinosaurus/
> >>>
> >>> with videos
> >>> http://news.nationalgeographic.com/news/2014/09/140911-spinosaurus-f
> >>> ossil-discovery-dinosaur-science/
> >>>
> >>> ***
> >>> with video
> >>>
> >>> http://phys.org/news/2014-09-shark-munching-spinosaurus-first-known-
> >>> dinosaur.html
> >>>
> >>> ***
> >>>
> >>> (including some skepticism by other paleontologists about
> >>> conclusions...)
> >>>
> >>> http://www.nature.com/news/swimming-dinosaur-found-in-morocco-1.1590
> >>> 1
> >>>
> >>> http://www.newscientist.com/article/dn26193-biggest-hunting-dinosaur
> >>> -was-an-aquatic-sharkgobbler.html
> >>>
> >>> On Thu, Sep 11, 2014 at 11:14 AM, Ben Creisler <bcreisler@gmail.com> 
> >>> wrote:
> >>>> Ben Creisler
> >>>> bcreisler@gmail.com
> >>>>
> >>>>
> >>>> It's out...
> >>>>
> >>>> Nizar Ibrahim, Paul C. Sereno, Cristiano Dal Sasso, Simone
> >>>> Maganuco, Matteo Fabbri, David M. Martill, Samir Zouhri, Nathan
> >>>> Myhrvold, and Dawid A. Iurino (2014) Semiaquatic adaptations in a
> >>>> giant predatory dinosaur.
> >>>> Science (advance online publication)
> >>>> DOI: 10.1126/science.1258750
> >>>> http://www.sciencemag.org/content/early/2014/09/10/science.1258750.
> >>>> abstract
> >>>>
> >>>> NOTE: Supplementary material is free.
> >>>>
> >>>>
> >>>> We describe adaptations for a semiaquatic lifestyle in the dinosaur
> >>>> Spinosaurus aegyptiacus. These adaptations include retraction of
> >>>> the fleshy nostrils to a position near the mid-region of the skull
> >>>> and an elongate neck and trunk that shift the center of body mass
> >>>> anterior to the knee joint. Unlike terrestrial theropods, the
> >>>> pelvic girdle is downsized, the hind limbs are short, and all of
> >>>> the limb bones are solid without an open medullary cavity, for buoyancy 
> >>>> control in water.
> >>>> The short, robust femur with hypertrophied flexor attachment and
> >>>> the low, flat-bottomed pedal claws are consistent with aquatic
> >>>> foot-propelled locomotion. Surface striations and bone
> >>>> microstructure suggest that the dorsal ?sail? may have been
> >>>> enveloped in skin that functioned primarily for display on land and in 
> >>>> water.
> >>>>
> >>>> ==
> >>>>
> >>>> Michael Balter (2014)
> >>>> Giant dinosaur was a terror of Cretaceous waterways.
> >>>> Science  345(6202): 1232
> >>>> DOI: 10.1126/science.345.6202.1232
> >>>> http://www.sciencemag.org/content/345/6202/1232.summary
> >>>>
> >>>>
> >>>>
> >>>> Researchers have long debated whether dinosaurs could swim, but
> >>>> there has been little direct evidence for aquadinos. Some
> >>>> tantalizing hints have appeared, however, in claimed "swim tracks"
> >>>> made by the bellies of dinos in Utah and oxygen isotopes indicating
> >>>> possible aquatic habitats in a group of dinosaurs called
> >>>> spinosaurs. Now, a research team working in Morocco has found the
> >>>> most complete skeleton yet of a giant carnivore called Spinosaurus,
> >>>> very fragmentary remains of which were first discovered in 1912 in
> >>>> Egypt. The new fossils not only confirm that Spinosaurus was bigger
> >>>> than Tyrannosaurus rex, but also show that it had evolutionary
> >>>> adaptations?ranging from pedal-like feet to a nostril far back on
> >>>> the head to high bone density like that of hippos?clearly suited for 
> >>>> swimming in lakes and rivers.
>