[ii] Venous Vessel Phylogeny

• Actinopterygii

  • Lateral abdominal veins lost
  • Pelvic fins drained by posterior cardinal veins
  • Blood from gas bladders empties into hepatic or common cardinal veins
• Dipnoi

  • Right posterior cardinal vein enlarged (postcaval vein)
  • Paired lateral abdominals fused
  • Ventral abdominal vein
• Larval and adult Urodela

  • Internal + external jugular veins
  • Lingual vein drain head
  • Postcaval vein
  • Ventral abdominal vein
  • Blood from hindlimb to liver sinusoids
  • Hepatic veins
  • Drain liver
• Adult Anurans

  • Posterior cardinal vein
  • Does not return blood from kidney to heart
• Reptilia

  • Internal, external jugular + subclavian from paired CCV

  • Enlarged, modified common cardinal vein -> precaval

  • Paired lateral abdominal veins, single postcava present

  • Posterior cardinal reduced -> azygos

  • Sinus venosus reduced
• Aves

  • External jugulars short
  • Internal jugulars long
  • Common cardinals modified
  • Postcava
  • Femoral, caudal, renal veins + hepatic veins
  • Hepatic and renal portal system present
• Mammalia

  • Renal portal, abdominal veins absent
  • Hepatic portal vein present
  • Cardinal vessels
  • Single precava, single postcava
  • Posterior vena cava divided:
  • Hepatic
  • Renal
  • Subcardinal