﻿MACHAEROIDES 
  EOTHEN 
  MATTHEW 
  — 
  GAZIN 
  341 
  

  

  noticeably 
  recurved 
  below 
  this 
  point. 
  The 
  length 
  of 
  the 
  canine 
  

   in 
  M. 
  eothen 
  cannot 
  be 
  determined 
  from 
  the 
  present 
  material; 
  

   however, 
  if 
  this 
  tooth 
  extended 
  as 
  far 
  as 
  the 
  flange 
  of 
  the 
  lower 
  

   jaw 
  it 
  would 
  have 
  had 
  a 
  length 
  of 
  about 
  3 
  cm. 
  beyond 
  the 
  alveolus. 
  

   The 
  canine 
  shows 
  no 
  evidence 
  of 
  serrations 
  along 
  the 
  anterior 
  or 
  

   posterior 
  margins. 
  

  

  The 
  premolars 
  of 
  M. 
  eothen 
  are 
  1-, 
  2-, 
  3-, 
  and 
  3-rooted, 
  respec- 
  

   tively. 
  F\ 
  preserved 
  only 
  on 
  the 
  right 
  side 
  when 
  found 
  but 
  

   subsequently 
  lost, 
  is 
  a 
  small, 
  simple, 
  conical 
  tooth 
  without 
  an 
  

   accessory 
  cuspule 
  and 
  separated 
  by 
  a 
  diastema 
  from 
  both 
  the 
  

   canine 
  and 
  P-. 
  In 
  both 
  Limnocyon 
  and 
  Thinocyon 
  P^ 
  is 
  2-rooted 
  

   and 
  exhibits 
  a 
  small 
  posterior 
  cuspule. 
  P- 
  of 
  M. 
  eothen, 
  in 
  addi- 
  

   tion 
  to 
  being 
  2-rooted, 
  retains 
  a 
  vestige 
  of 
  a 
  posterior 
  cuspule. 
  

   The 
  tooth 
  is 
  relatively 
  much 
  smaller 
  and 
  transversely 
  more 
  

   compressed 
  than 
  in 
  Limnocyon. 
  P% 
  on 
  the 
  other 
  hand, 
  is 
  much 
  

   better 
  developed 
  than 
  in 
  Thinocyon 
  and 
  apparently 
  than 
  in 
  

   Limnocyon. 
  This 
  tooth, 
  preserved 
  only 
  on 
  the 
  left 
  side, 
  has 
  

   a 
  minute 
  parastyle 
  and 
  a 
  rather 
  well 
  developed 
  posterior 
  cusp 
  

   or 
  crest, 
  approximating 
  P* 
  in 
  this 
  respect. 
  The 
  lingual 
  root 
  

   is 
  slender 
  but 
  extends 
  markedly 
  inward 
  from 
  about 
  midway 
  

   of 
  the 
  tooth 
  length 
  and 
  supports 
  a 
  very 
  small 
  deuterocone. 
  

   P* 
  is 
  relatively 
  robust 
  with 
  a 
  prominent 
  parastyle 
  before 
  and 
  a 
  

   trenchant 
  cusp 
  posterior 
  to 
  the 
  large 
  backward 
  sloping 
  primary 
  

   cusp. 
  The 
  deuterocone 
  portion 
  is 
  broad 
  and 
  well 
  defined, 
  extend- 
  

   ing 
  lingually 
  from 
  the 
  midportion 
  of 
  the 
  tooth. 
  The 
  deuterocone 
  

   portion 
  does 
  not 
  project 
  forward 
  as 
  it 
  does 
  in 
  Thinocyon 
  or 
  (to 
  a 
  

   less 
  degree) 
  in 
  Limnocyon. 
  The 
  deuterocone 
  is 
  situated 
  on 
  the 
  

   lingual 
  margin 
  of 
  the 
  talon 
  and 
  is 
  connected 
  with 
  the 
  primary 
  

   cusp 
  by 
  a 
  low 
  crest 
  across 
  the 
  forward 
  part 
  of 
  the 
  talon. 
  A 
  small, 
  

   shallow 
  basin 
  is 
  enclosed 
  between 
  this 
  forward 
  crest 
  and 
  the 
  

   low 
  cingular 
  crest 
  around 
  the 
  posterior 
  margin 
  of 
  the 
  talon. 
  

  

  The 
  difference 
  in 
  development 
  of 
  the 
  various 
  premolars 
  is 
  

   rather 
  striking 
  in 
  comparison 
  with 
  related 
  forms. 
  P' 
  and 
  P* 
  are 
  

   relatively 
  small 
  and 
  less 
  progressive, 
  probably 
  reduced 
  from 
  an 
  

   earlier 
  but 
  more 
  advanced 
  state, 
  paralleling 
  the 
  machairodonts 
  in 
  

   this 
  respect, 
  as 
  an 
  accompanying 
  factor 
  in 
  sabertooth 
  specializa- 
  

   tion. 
  P\ 
  however, 
  has 
  retained 
  a 
  more 
  advanced 
  stage 
  of 
  devel- 
  

   opment 
  and 
  undoubtedly 
  continued 
  to 
  be 
  a 
  significant 
  and 
  func- 
  

   tional 
  tooth 
  in 
  the 
  later 
  and 
  more 
  advanced 
  Apntaeluntfi, 
  as 
  

   indicated 
  by 
  the 
  well-developed 
  and 
  trenchant 
  P^ 
  with 
  which 
  it 
  

   occludes 
  in 
  the 
  lower 
  jaw 
  of 
  the 
  Uinta 
  form. 
  

  

  ^r, 
  the 
  upper 
  sectional 
  tooth 
  in 
  Machneroides 
  eothen, 
  has 
  taken 
  

   on 
  a 
  very 
  trenchant 
  appearance 
  as 
  compared 
  either 
  with 
  the 
  

  

  