Re: Segnosaurs

["Jaime Headden" <jaemei@hotmail.com>]

<Last time I looked, segnosaur remains consisted of a handful of bones.

1) How can one be so sure of the appearance of segnosaurs? (or agree so 
much on guessing it)>

Including both statements above, segnosaurs are known by pretty much 
every bone in the dinosaurs' bodies, but from different specimens. 
*Alxasaurus* is known from a nearly complete skeleton, and the first 
relatively complete forelimbs and vertebral column; *Erlikosaurus* from 
a few skeletons (less than 25% complete each that make up a poorly 
understood form) but he gave us the skull and complete pes; 
*Segnosaurus* from a single specimen gave us the pelvis, hindlimb, and 
several other parts, mostly fragments; *Enigmosaurus*, unfortunately, is 
a pelvis; and *Therizinosaurus* from a huge set of claws, vertebrae, 
parts of tyhe hindlimb, and ribs, with referred forelimb, giving us an 
unfortunately incomplete picture of the thing; and *Nanshiungosaurus* 
from two vertebral columns and pelvises. This gives us a pretty 
reasonable picture of the creatures: Long neck, short back with shallow 
chest but deep sides and wide gut, short forelimbs with tibia same 
length or shorter than femur, and short, deep tail. Manus is adorned 
with large claws, curved in all forms known to have them but for 
*Therizinosaurus*; all pedal claws are recurved and large, with digit I 
ungual the largest.

>From all this, we can get a good picture of the appearance of several 
segnosaurs (properly, therizinosauroids) with the others being guessed 
upon. *Alxasaurus* and *Therizinosaurus'* inclusion in the basic 
segnosaur tree are under debate, so their position is not assured, but 
this does not actually change our picture of a segnosaur, for all the 
rest are sufficient to fill in details the others lack; we can be pretty 
certain of this because all have parts that over lap at least one of the 
others, and all are pretty similar.

<2) What do we know/think we now about segnosaurs? Where can I find more 
info?>

You can find the best debate system used for these creatures right here, 
or look for the material in the original literature, which research into 
the library will probably turn up, as well as perusal into the following 
books:

_The Complete Dinosaur_ Padian & Brett-Surman, 1997
_The Encyclopedia of Dinosaurs_ Currie & ?, 1997
_Dinosaurs: the Encyclopedia_ Glut, 1997

All are rich and cover various fields, often overlapping, but getting to 
read at least two of these will assure a fair knowledge of any dino 
subject, dino taxa, and whathaveyou.

<3) How can we be sure that a skeleton belonged to a slightly different 
dinosaur spieces, and not just a e.g. younger of the same spieces?>

Morphological differences and geographic distribution. All material 
known is assured maturity through complete suturing, fusion of elements, 
and especially neurocentral sutures. *Enigmosaurus* lacks vertebrae, the 
only segnosaur to do so, so we are not absolutely sure it is adult, and 
may persist as a younger form of some other known segnosaur (the only 
one big enough, of course, is *Therizinosaurus*).

<4) I have not seen "Lost World" yet. Is it as embarrasing as the first 
"JP"?>

Actually, in some ways, it's better. There is less concern towards the 
dinosaurs as a-1 subjects, and instead focus on modern ecological 
problems with dinosaurs playing the proverbial guinea pigs. The 
*Velociraptor* are still ten feet long and the size of *Deinonychus* 
(Hammond's team may have misidentified the skeletal features as 
*Velociraptor* rather than *Deinonychus*, as we are having difficulty 
with now. Who knows?).

Pair-hunting tyrannosaurs, juveniles, they really add a little family to 
the picture, along with Ian's daughter, Kelly, but then there's the fact 
that it's gorier, _many_ more people die, and there's an obvious 
Bakker-bashing with the character of Robert Burke. But the expression on 
the bull rex's face when baby rex nabs his first kill is priceless.

But rate the movie yourself, rent it.

Jaime A. Headden

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