﻿PROCEEDINGS 
  OF 
  THE 
  UNITED 
  STATES 
  NATIONAl 
  MUSEUM 
  

  

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  SMITHSONIAN 
  INSTITUTION 
  

   U. 
  S. 
  NATIONAL 
  MUSEUM 
  

  

  V' 
  I. 
  ')6 
  Washingtor: 
  1946 
  No. 
  3202 
  

  

  MACHAEROIDES 
  EOTHEN 
  MATTHEW, 
  THE 
  SABER- 
  

   TOOTH 
  CREODONT 
  OF 
  THE 
  BRIDGER 
  EOCENE 
  

  

  By 
  C. 
  Lewis 
  Gazin 
  

  

  The 
  1940 
  Smithsonian 
  Institution 
  expedition 
  to 
  the 
  Bridger 
  

   Basin 
  of 
  Wyoming' 
  had 
  unusual 
  good 
  fortune 
  in 
  securing 
  skeletal 
  

   remains 
  of 
  the 
  rare 
  creodont 
  Machaeroides 
  eothen. 
  The 
  materials, 
  

   consisting 
  of 
  skull, 
  lower 
  jaws, 
  and 
  other 
  skeletal 
  portions 
  of 
  one 
  

   individual, 
  were 
  found 
  by 
  Franklin 
  Pearce 
  in 
  low 
  exposures, 
  

   probably 
  of 
  Bridger 
  "C," 
  immediately 
  to 
  the 
  north 
  of 
  Twin 
  

   Buttes, 
  about 
  30 
  miles 
  southwest 
  of 
  Green 
  River, 
  Wyo. 
  Previous 
  

   finds 
  of 
  this 
  remarkable 
  sabertooth 
  form, 
  so 
  far 
  as 
  known, 
  are 
  

   limited 
  to 
  the 
  lower 
  jaw 
  portions 
  described 
  by 
  Matthew 
  ^ 
  in 
  1909. 
  

  

  The 
  skull, 
  U.S.N.M. 
  No. 
  17059, 
  v/as 
  found 
  with 
  the 
  lower 
  jaws 
  

   in 
  a 
  position 
  of 
  articulation, 
  and 
  although 
  essentially 
  complete 
  

   there 
  has 
  been 
  a 
  small 
  amount 
  of 
  transverse 
  crushing 
  and 
  dis- 
  

   tortion 
  so 
  that 
  the 
  riglit 
  side 
  of 
  the 
  skull 
  is 
  higher 
  than 
  the 
  left. 
  

   The 
  remainder 
  of 
  the 
  skeleton 
  includes 
  portions 
  of 
  the 
  vertebral 
  

  

  lumn, 
  both 
  humeri 
  and 
  femora, 
  the 
  right 
  radius 
  and 
  ulna, 
  an 
  

   incomplete 
  left 
  tibia, 
  and 
  fragments 
  of 
  the 
  pectoral 
  and 
  jielvic 
  

   girdlrs. 
  The 
  feet 
  were 
  not 
  present 
  oxcopt 
  for 
  a 
  carpal 
  and 
  two 
  

   metacarpal 
  bones. 
  

  

  Matthew 
  readily 
  appreciated 
  the 
  indications 
  in 
  the 
  lower 
  jaw 
  

   portions 
  of 
  Machaeroides 
  eothen 
  of 
  a 
  modification 
  nearly 
  parallel- 
  

   ing 
  that 
  of 
  the 
  machairodont 
  forms 
  among 
  the 
  Fissipedia. 
  In 
  

   the 
  materials 
  he 
  had 
  at 
  hand 
  these 
  modifications 
  were 
  not 
  too 
  

   evident, 
  and 
  R. 
  H. 
  Denison 
  - 
  was 
  inclined 
  to 
  consider 
  the 
  M. 
  

   eothen 
  jaw 
  as 
  resembling 
  Felin 
  and 
  not 
  truly 
  "sabertooth." 
  The 
  

  

  ' 
  Matthew, 
  W. 
  D.. 
  Mem. 
  Amcr. 
  Mus. 
  N*t 
  Hist., 
  vol. 
  9, 
  pt. 
  6, 
  pp. 
  4B2-<63, 
  1909. 
  

   ' 
  n..nl<»on. 
  R. 
  II.. 
  Ann. 
  N«w 
  York 
  Acad. 
  8cl.. 
  vol. 
  87. 
  p. 
  181, 
  1938. 
  

  

  335 
  

  

  