Billingsellida Explained

An order of brachiopods containing the families:

• Suborder Billingsellidina
  • Superfamily Billingselloidea
    • Family Billingsellidae
• Suborder Clitambonitidina
  • Superfamily Clitambonitoidea
    • Family Clitambonitidae
    • Family Gonambonitidae
  • Superfamily Polytoechioidea
    • Family Polytoechiidae