Jawless fish - Animals in the Habitats and the Fossil sites, and Biodiversity

Classified animal picture guide. Highlighting the link of species shows the images, and clicking a link shows Evolutionary Tree.
The followings are extinct jawless fishes excavated and extant jawless fishes in the world. The primitive jawless fishes evolved from Chordate, and lived from Cambrian. The explanation in brackets is the ages they lived in extinct species, and the habitat in extant species. 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 is shown in the Geological Time Table. The followings are a part of the Evolutionary Tree.
  • Kingdom Animalia
    • Phylum Chordata ⇒ Class Fish
      Primitive chordata Haikouella (542~513 Mya), Pikaia (513~501 Mya), Promissum (449~443.7 Mya), Palaeospondylus (397~385 Mya)
      • Subphylum Vertebra
        • Superclass Agnatha (Oldest fishes, Hagfish, Lamprey) Jawless fish
          Jawless fish Haikouichthys (535–520 Mya; Earliest fish), Myllokunmingia (542 to 516 Mya; Earliest fish)
        • Infraphylum Gnathostomata (Jawed vertebrates)
          • Class Placodermi (extinct group; 418.1~245 Mya) Armoured fish
          • Class Chondrichthyes (Ray, Shark; 466 Mya~) Cartilaginous fish
          • Class Acanthodii (extinct group; 421.3~255 Mya) Spiny sharks
          • Superclass Osteichthyes (Bony fish)
            • Class Sarcopterygii (Four-limbed vertebrate, Coelacanth, Lungfish; 422.9 Mya~) Lobe-finned fish
            • Class Actinopterygii (Most living fishes; 421.3 Mya~) Ray-finned fish