RE: Late Cretaceous titanosaur armor

["Jaime A. Headden" <qilongia@yahoo.com>]

Tim Donovan (uwrk2@yahoo.com) wrote:

<If armor was related to defense, it is possible that relatively small
titanosaurs such as Saltasaurus needed it whereas more massive taxa did
not. I don't think Paralititan or Argentinosaurus were armored.
Alamosaurus may have been the largest titanosaur of the late
Maastrichtian. It is probably known from as much material as European or
Malagasy taxa but no armor has been found.>

  There are plenty of smallish titanosaurs from South America and India
for which armor is unknown, nor articulated. VERY few titanosaurs show
articulated armor, and some species, such as *Augustinia,* show armor that
is so bizarrely strange that if known only from the armor, it is not
likely to actually be referred to a titanosaur, maybe a stegosaur or other
thyreophore. The phylogenetic history and distribution of armor in
titanosaur species, and in actual titanosaur armor arrangement, is
unknown, leading one to a lack of basis for making much formulative
hypothesis. It is certainly testable about LARGE titanosaurs bearing
armor, especially in species rich diversities of small species with no
armor, as acknowledged for *Alamosaurus.* However, once again, absence of
evidence DOES NOT mean evidence of absence; it is but an unknown unless ou
can PROVE *Alamosaurus* lacked armor to suggest smaller forms than 80+ ft
lacked armor, and *Almosaurus* is an advanced species and large for which
armor is known for relatives, so bracketing should recover it as armored
before excluding the idea of armor hits the table. Some smaller
titanosaurids, like *Neuquensaurus,* I beleive, also lack articulated
armor, while others (*Saltasaurus* and *Laplatasaurus,* have had armor
referred to them -- I may be wrong on the species here, but not all
Neuquen Group sauropods have armor associated).

<I think it was associated in the case of Ampelosaurus.>

  A single specimen. Take *Hypselosaurus,* known from fragments to which
nests _and_ armor were referred. Why not *Hypselosaurus* _as well_?

<As far as I know, no titanosaur armor has been found in any of the
Nemegtian exposures after more than 50 years of work, even though O.
skarzynskii (=N. mongoliensis?) is now considered a titanosaur, and a
considerable amount of Nemegtian sauropod material is now known from
several localites. Maybe they were all armored but I don't think we can
assume this.>

  This is irrelevant. 30 years of research into the Nemegt failed to
recover *Bagaraatan* until the early 90's, and it is a 10-foot predator
with a huge jaw ... one should think it would be found, but for all the
research, TWO sauropod skulls and ONE sauropod skeleton are known. That's
awesome recovery, right there that bespeaks of the Nemegt's recovery rate,
promising if you wanted to find *Tarbosaurus* and lizards.

=====
Jaime A. Headden

  Little steps are often the hardest to take.  We are too used to making leaps 
in the face of adversity, that a simple skip is so hard to do.  We should all 
learn to walk soft, walk small, see the world around us rather than zoom by it.

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)

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