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You Hailu and Mazongshan



To all,

  You Hailu kindly supplied me with a copy of his thesis, and so far, it
appears to be very interesting. While *Archaeoceratops* and his new
hadrosauroid are treated with a cladistic analysis, his new titanosaur is
not; the cladistic analysis of *Archaeoceratops* agrees with recent work
by Makovicky, and that of the hadrosauroid places it as the most basal
hadrosauroid, but it doesn't take many steps to place it in a trichotomy
with "iguanodontoids" proper and hadrosauroids. The new hadrosauroid is
very similar to both *Altirhinus* on one side and *Jinzhousaurus* on the
other, is short-snouted, and has a dentary more than 75% the jaw length,
as in *Ouranosaurus* and hadrosaurs but unlike the "generic" basal
hadrosaurs *Protohadros* or *Eolambia*, or the basal "iguanodontoid"
*Probactrosaurus gobiensis*. His new titanosaur is said to be very similar
to *Tangvayosaurus*, and the general placement compared to several basal
forms, including *Malawisaurus*, *Phuwiangosaurus*, and *Cedarosaurus*,
tends to agree with recent placement of *Tangvayosaurus* (=*Titanosaurus
falloti*) as a titanosauroid. *Opisthocoelicaudia* is not compared but
*Andesaurus* is. The most interesting thing about the skeleton is perhaps
the distal caudals which, rather than being truly biconvex, have small
mounds on both ends with well-defined rims and a pit dorsal to the mound
(the last is central in the facet, and they do not interlock); despite
this, You says they are not biconvex, which might be a matter of degree
rather than absolute condition; his new form might therefore be
intermediate between the amphiplatyan and biconvex conditions.

  As a note, Mazongshan in Chinese translates to "Horse Mane Mountain", a
name You uses rather frequently; the name for his new hadrosauroid comes
from the Latin, _equus_ and _jubus_, respectively, dropping "mountain".
Stratigraphically, the level from which these forms as well as
*Nanshiungosaurus bohlini* derive appears to balance around the Albian,
based largely on palynological data; the fossils hail from beds relegated
to the Chijinbao or Dugou Formations, which are Early to Middle Cretaceous
in age, and part of the Xinminbao Group. *Archaeoceratops*, an
iguanodontid, and an ornithomimid are known from the lower, red, beds of
the Chijinbao; the middle, grey, beds of the Dugou yield an ornithomimid,
the new hadrosauroid, and the new titanosaur.

  Cheers,

=====
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.

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