﻿180 
  0. 
  C. 
  Marsh 
  — 
  Restoration 
  of 
  Stegosaurus. 
  

  

  a 
  lithographic 
  plate 
  to 
  accompany 
  the 
  monograph 
  of 
  the 
  

   Stegosauria, 
  prepared 
  by 
  the 
  writer 
  for 
  the 
  U. 
  S. 
  Geological 
  

   Survey. 
  

  

  In 
  this 
  restoration, 
  the 
  animal 
  is 
  represented 
  as 
  walking, 
  and 
  

   the 
  position 
  is 
  adapted 
  to 
  that 
  motion. 
  The 
  head 
  and 
  neck, 
  

   the 
  massive 
  fore 
  limbs, 
  and, 
  in 
  fact, 
  the 
  whole 
  skeleton, 
  indi- 
  

   cate 
  slow 
  locomotion 
  on 
  all 
  fonr 
  feet. 
  The 
  longer 
  hind 
  limbs 
  

   and 
  the 
  powerful 
  tail 
  show, 
  however, 
  that 
  the 
  animal 
  could 
  

   thus 
  support 
  itself, 
  as 
  on 
  a 
  tripod, 
  and 
  this 
  position 
  must 
  

   have 
  been 
  easily 
  assumed 
  in 
  consequence 
  of 
  the 
  massive 
  hind 
  

   quarters. 
  

  

  In 
  the 
  restoration 
  as 
  here 
  presented, 
  the 
  dermal 
  armor 
  is 
  the 
  

   most 
  striking 
  feature, 
  but 
  the 
  skeleton 
  is 
  almost 
  as 
  remarkable, 
  

   and 
  its 
  high 
  specialization 
  was 
  evidently 
  acquired 
  gradually 
  as 
  

   the 
  armor 
  itself 
  was 
  developed. 
  Without 
  the 
  latter, 
  many 
  

   points 
  in 
  the 
  skeleton 
  would 
  be 
  inexplicable, 
  and 
  there 
  are 
  still 
  

   a 
  number 
  that 
  need 
  explanation. 
  

  

  The 
  small, 
  elongated 
  head 
  was 
  covered 
  in 
  front 
  by 
  a 
  horny 
  

   beak. 
  The 
  teeth 
  are 
  confined 
  to 
  the 
  maxillary 
  and 
  dentary 
  

   bones, 
  and 
  are 
  not 
  visible 
  in 
  the 
  figure 
  here 
  given. 
  They 
  are 
  

   quite 
  small, 
  with 
  compressed, 
  fluted 
  crowns, 
  and 
  indicate 
  that 
  

   the 
  food 
  of 
  this 
  animal 
  was 
  soft, 
  succulent 
  vegetation. 
  The 
  

   vertebrse 
  are 
  solid, 
  and 
  the 
  articular 
  faces 
  of 
  the 
  centra 
  are 
  

   bi-concave 
  or 
  nearly 
  flat. 
  The 
  ribs 
  of 
  the 
  trunk 
  are 
  massive, 
  

   and 
  placed 
  high 
  above 
  the 
  centra, 
  the 
  tubercle 
  alone 
  being 
  

   supported 
  on 
  the 
  elevated 
  diapophysis. 
  The 
  neural 
  spines, 
  

   especially 
  those 
  of 
  the 
  sacrum 
  and 
  anterior 
  caudals, 
  have 
  their 
  

   summits 
  expanded 
  to 
  aid 
  in 
  supporting 
  the 
  massive 
  dermal 
  

   armor 
  above 
  them. 
  The 
  limb 
  bones 
  are 
  solid, 
  and 
  this 
  is 
  true 
  

   of 
  every 
  other 
  part 
  of 
  the 
  skeleton. 
  The 
  feet 
  were 
  short 
  and 
  

   massive, 
  and 
  the 
  terminal 
  phalanges 
  of 
  the 
  functional 
  toes 
  were 
  

   covered 
  by 
  strong 
  hoofs. 
  There 
  were 
  five 
  well-developed 
  digits 
  

   in 
  the 
  fore 
  foot, 
  and 
  only 
  three 
  in 
  the 
  hind 
  foot, 
  the 
  first 
  toe 
  

   being 
  rudimentary, 
  and 
  the 
  fifth 
  entirely 
  wanting. 
  

  

  In 
  life, 
  the 
  animal 
  was 
  protected 
  by 
  a 
  powerful 
  dermal 
  

   armor, 
  which 
  served 
  both 
  for 
  defense 
  and 
  offense. 
  The 
  throat 
  

   was 
  covered 
  by 
  a 
  thick 
  skin 
  in 
  which 
  were 
  imbedded 
  a 
  large 
  

   number 
  of 
  rounded 
  ossicles, 
  as 
  shown 
  in 
  the 
  figure. 
  The 
  

   gular 
  portion 
  represented 
  was 
  found 
  beneath 
  the 
  skull, 
  so 
  that 
  

   its 
  position 
  in 
  life 
  may 
  be 
  regarded 
  as 
  definitely 
  settled. 
  The 
  

   series 
  of 
  vertical 
  plates 
  which 
  extended 
  above 
  the 
  neck, 
  along 
  

   the 
  back, 
  and 
  over 
  two-thirds 
  of 
  the 
  tail, 
  is 
  a 
  most 
  remarkable 
  

   feature, 
  which 
  could 
  not 
  have 
  been 
  anticipated, 
  and 
  would 
  

   hardly 
  have 
  been 
  credited 
  had 
  not 
  the 
  plates 
  themselves 
  been 
  

   found 
  in 
  position. 
  The 
  four 
  pairs 
  of 
  massive 
  spines 
  charac- 
  

   teristic 
  of 
  the 
  present 
  species, 
  which 
  Were 
  situated 
  above 
  the 
  

   lower 
  third 
  of 
  the 
  tail, 
  are 
  apparently 
  the 
  only 
  part 
  of 
  this 
  

  

  