New Mammals in _American Museum Novitates_

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

  Meng J., A. R. Wyss, Hu Y.-m., Wang Y.-q., G. J. Bowen, and P. L. Koch. 2005.
    Glires (Mammalia) from the late Paleocene Bayan Ulan locality of Inner
    Mongolia. _American Museum Novitates_ 3473:1-25.

Abstract:
  "Two new early diverging members of Glires, *Eomylus bayanulanensis*, n.sp.
   and *Palaeomylus lii*, n.gen. and n.sp., are described from the late
   Paleocene Bayan Ulan Fauna, Inner Mongolia, China. These species add
   significantly to the diversity of Glires known from the early Paleogene of
   Asia. *E. bayanulanensis* and *Palaeomylus* sp. come from the lowest level
of
   the Bayan Ulan section, from which the classic Bayan Ulan Fauna was
   collected. *Palaeomylus lii* and specimens belonging to two other genera of
   mammals, *Pseudictops* and *Palaeostylops*, are found from a horizon about 8
   m above strata yielding the Bayan Ulan Fauna. These taxa are tentatively
   regarded as constituting a distinct faunal assemblage, which may prove to be
   of biostratigraphic utility within the region. Two calcanea tentatively
   assigned to *Gomphos* from a stratigraphic horizon slightly above the bed
   producing *P. lii* suggest the presence of strata of Early Eocene age in the
   Bayan Ulan section."

  Hu Y.-m., R. C. Fox, Wang Y.-q. and Li C.-k. 2005. A new spalacotheriid
    symmetrodont from the early Cretaceous of northeastern China. _American
    Museum Novitates_ 3475:1-20.

Abstract:
  "Symmetrodonts are Mesozoic mammals having lower molars with nearly
   symmetrical trigonids but lacking talonids. They appear to be stem members
of
   the mammalian clade that led to extant tribosphenic mammals, but the fossil
   record of symmetrodonts is poor. Here we report a new genus and species of
an
   acute-angled spalacotheriid symmetrodont, *Heishanlestes* changi, n.gen. and
   n.sp., represented by well-preserved lower jaws with teeth from the Early
   Cretaceous of northeastern China. The new mammal has four tightly spaced
   premolars and three morphological groups of lower molars, in which the first
   molar has an obtuse trigonid angle and the last two molars have a large
   neomorphic cusp in the center of the trigonid, a feature not seen in other
   mammals. *Heishanlestes* appears to be a specialized member of the
   spalacotheriid subfamily, Spalacolestinae, which is otherwise only known
from
   North America. The animal probably used the premolars to crush its prey
   before shearing it with the molars."

  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.

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


                
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