World problems

Title
Threatened species of Hysterocinetida
Threatened species of Hysterocinetia
Threatened species of Glossata
Threatened species of Aglossata
Threatened species of Neopseustina
Threatened species of Odontostomatida
Threatened species of Batrachoidiformes
Threatened species of Piroplasmia
Threatened species of Merostomata
Threatened species of Eucommiales
Threatened species of Tanaidacea
Threatened species of Thermosbaenacea
Threatened species of Spelaeogriphacea
Extinct species of Ptycholepiformes
Extinct species of Anaspidiformes
Extinct species of Thelodontiformes
Threatened species of Branchiura
Extinct species of Perleidiformes
Extinct species of Semionotiformes
Extinct species of Macrosemiiformes
Extinct species of Pycnodontiformes
Extinct species of Peltopleuriformes
Extinct species of Leptolepidiformes
Extinct species of Saurichthyiformes
Extinct species of Haplolepidiformes