title: Ussuritidae
text: # Ussuritidae
  
  Ussuritidae are ancestral, Triassic, Phylloceratina characterized by generally smooth, discoidal, evolute shells with rounded venters and little or no ornamentation and by sutures with primitive monophyllitic saddles with a single terminal branch or leaflet.
  
  The Ussuritidae are most likely derived from the Dieneroceratidae and give rise to the Discophyllitidae. Seven genera are included:
  
  * Ussurites
  * Palaeophyllites
  * Monophyllites
  * Majsvarites
  * Leiophyllites
  * Eopsiloceras
  * Eophyllites
  
  Genera are distinguished on the basis of shell morphology and characteristics of the suture.
  
  Ussuritidae are also known as the Monophyllitidae, a junior synonym. Palaeophyllitidae, for Palaeophyllites, is sometimes found in the literature.
  
  