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Re: Sauropod Energetics (Peristaltic pumps for arteries?)



Of some note in this discussion:

Indricotherium. (2006).
Encyclopædia Britannica.
Retrieved January 25, 2006, from Encyclopædia Britannica Premium Service. http://www.britannica.com/eb/article?tocId=9012066


"Indricotherium, formerly Baluchitherium, genus of giant browsing perissodactyls found as fossils in Asian deposits of the Late Oligocene and Early Miocene epochs (30 to 16.6 million years ago). The indricotherium, which was related to the modern rhinoceros but was hornless, was the largest land mammal that ever existed. It stood about 5.5 m (18 feet) high at the shoulder, was 8 m (26 feet) long, and weighed an estimated 30 tons, which is more than four times the weight of the modern elephant. Its skull, small in proportion to its body, was more than 1.2 m (4 feet) in length. Indricotherium had relatively long front legs and a long neck; thus, it was probably able to browse on the leaves and branches of trees. Its limbs were massive and strongly constructed."

Note that _Indricotherium_'s SHOULDER was the height of the largest giraffe's entire body! It had a long neck and a large skull. (In comparision to the giraffe or the sauropod, neither of which had a large skull). My estimate for the height of the beast (its former name, _Baluchitherium_, means beast from Baluchistan), is around 6.75 meters. (Note also, that a possibile synonym for _Indricotherium_ is _Paraceratherium_). The heart-head distance was probably around 2 meters, and I image that its blood pressure would be even higher than extant giraffes.

The article in Wikipedia that Guy referenced, also describes some giraffe adaptations for handling the extremes in BP that giraffes experience. I gonna guess that _Indricotherium_ and sauropods had vey similar (or even more extreme) adaptations.

Allan Edels


From: Guy Leahy <xrciseguy@sbcglobal.net>
Reply-To: xrciseguy@sbcglobal.net
To: rtravsky@uwyo.edu, dinosaur@usc.edu
Subject: Re: Sauropod Energetics (Peristaltic pumps for arteries?)
Date: Wed, 25 Jan 2006 13:11:45 -0800 (PST)

About 5.5 meters, according this reference:

http://en.wikipedia.org/wiki/Giraffe

A 5 m tall giraffe has a heart-head distance of a
little over 1.5 m, and a systolic blood pressure of
~210 mm Hg:

http://compphys.bio.uci.edu/hicks/R629.pdf

Interestingly, in mammals blood pressure scales
positively with body mass, but in birds blood pressure
is independent of body mass:

http://www.journals.uchicago.edu/PBZ/journal/issues/v73n4/990118/brief/990118.abstract.html

For example, a house sparrow has a systolic blood
pressure of 180 mm Hg, while the systolic blood
pressures of an ostrich and emu are 191 and 149 mm Hg.

A 5 m tall giraffe has a total gravitational pressure
of 370 mm Hg.  According to Kent's estimations the
total gravitational pressure in Apatosaurus and
Diplodocus would have been similar, since the maximum
height each could achieve would have been 5-6 m and 4
m, respectively. Giraffe-like cardiovascular
adaptations would have worked quite well for such
sauropods, and do not require hypothetical adaptations
which have not been documented to exist in any extant
vertebrate.

Guy Leahy


--- "Richard W. Travsky" <rtravsky@uwyo.edu> wrote:

> On Wed, 25 Jan 2006, Guy Leahy wrote:
>
> > The following article discusses why such a
> solution to
> > high blood pressures in rearing sauropods is
> unlikely:
> >
>
----------------------------------------------------------------
> > Proceedings: Biological Sciences
> > ISSN: 0962-8452 (Paper) 1471-2954 (Online)
> > Issue: Volume 267, Number 1455 / September 22,
> 2000
> >
> > Pages: 1883 - 1887
> > DOI: 10.1098/rspb.2000.1225
> > URL: Linking Options
> > Hearts, neck posture and metabolic intensity of
> > sauropod dinosaurs
> >[...]
>
> So, how big can a giraffe get? What's the biggest
> one on record?
> (since they're about it for something analogous)
>