Evolutionary Tree of Molluscs

Note that Mya is million years ago. For example, "48.6～40.4 Mya" shows a range between 48.6 and 40.4 million years ago. The time range and the epoch are shown in the Geological Time Table.

Phylogenetic Tree of Molluscs

Kingdom Animalia
- Phylum Mollusca
  - Class Hyolitha (542～255 Mya)
  - Class Tentaculita (490～228 Mya)
  - Class Caudofoveata (Worm-like organisms)
  - Class Aplacophora (Solenogasters, Worm-like organisms)
  - Class Polyplacophora (Chitons)
    - Order Paleoloricata (501 Mya～)
    - Order Neoloricata (460.5 Mya～)
  - Class Monoplacophora (Limpet-like organisms; 530 Mya～)
  - Class Gastropoda (Abalone, Limpets, Conch, Nudibranchs; 520 Mya～)
    - Subclass Archaeobranchia
    - Subclass Eogastropoda
      - Superorder Patellogastropoda (True limpets; 249.7 Mya～)
    - Subclass Orthogastropoda
      - Superorder Cocculiniformia (Deepwater limpets; 112 Mya～)
      - Superorder Vetigastropoda (Limpets; 488.3 Mya～) Snail
      - Superorder Neritaemorphi (Snails)
        
        Order Neritopsina (450 Mya～) Snail
      - Superorder Caenogastropoda (Marine gastropods; 471.8 Mya～)
        
        Order Architaenioglossa (245 Mya～) Snail
        Order Sorbeoconcha (309.2 Mya～) Snail
        Order Hypsogastropoda (449 Mya～) Snail
      - Superorder Heterobranchia (449 Mya～)
        
        Order Heterostropha (388.1 Mya～) Snail
        Order Opisthobranchia (Sea hares, Sea slugs; 418.7 Mya～)
        Order Pulmonata (Pulmonates; 145.5 Mya～)
  - Class Cephalopod (Squid, Octopus, Cuttlefish, Nautilus, Ammonite; 490 Mya～)
    - Subclass Nautiloidea (Nautiluses)
      - Order Plectronocerida
      - Order Endocerida (488.3～345.3 Mya)
      - Order Actinocerida (488.3～312 Mya)
      - Order Pseudorthocerida (468.1～251 Mya)
      - Order Tarphycerida (488.3～418.1 Mya)
      - Order Oncocerida (479～312 Mya)
      - Order Nautilida (Nautiluses; 488.3 Mya～) Nautilus
      - Order Orthocerida (488.3～112 Mya)
    - Subclass Ammonoidea (Ammonites)
      - Order Goniatitida (409.1～140.2 Mya) Ammonite
      - Order Clymeniida (376.1～359.2 Mya) Ammonite
      - Order Ceratitida (488.3～189.6 Mya) Ammonite
      - Order Ammonitida (542～65.5 Mya) Ammonite
    - Subclass Coleoidea (Squid, Octopus, Cuttlefish)
      - Order Belemnitida (339.4～65.5 Mya)
      - Superorder Decapodiformes
        
        Order Spirulida (Ram’s Horn Squid) Squid
        Order Sepiida (Cuttlefish; 161.2 Mya～) Squid
        Order Sepiolida (Pygmy, Bobtail, Bottletail squid) Squid
        Order Teuthida (Squid; 164.7 Mya～) Squid
      - Superorder Octopodiformes
        
        Order Vampyromorphida (Vampire squid) Ocutopus
        Order Octopoda (Octopus; 164.7～11.61 Mya) Ocutopus
  - Class Bivalvia (Clams, Oysters, Scallops, Mussels; 530 Mya～)
    - Subclass Palaeotaxodonta
      - Order Nuculoida (Nut clams; 488.3 Mya～) Bivalve
    - Subclass Cryptodonta
      - Order Solemyoida (Awning clams; 426.2 Mya～) Bivalve
    - Subclass Pteriomorphia (Oysters, Mussels)
      - Order Arcoida (476.8 Mya～) Bivalve
      - Order Limoida (File shells; 376.1 Mya～) Bivalve
      - Order Mytiloida (Sea mussels; 476.8 Mya～) Bivalve
      - Order Ostreoida (Oysters; 260.5～55.8 Mya) Bivalve
      - Order Pterioida (468.1 Mya～) Bivalve
    - Subclass Paleoheterodonta
      - Order Trigonioida (428.2～5.33 Mya) Bivalve
      - Order Unionoida (Freshwater Mussels; 388.1 Mya～) Bivalve
    - Subclass Heterodonta (Clams, Cockles)
      - Order Hippuritoida (Rudists; 436～65.5 Mya) Bivalve
      - Order Myoida (Soft-shell clams; 272.5 Mya～) Bivalve
      - Order Veneroida (Cockles; 490 Mya～) Bivalve
    - Subclass Anomalodesmata
      - Order Pholadomyoida (468.1 Mya～) Bivalve
  - Class Scaphopoda (Tusk shells)
    - Order Dentaliida (422.9 Mya～)
    - Order Gadilida (284 Mya～)