The first fish lineages belong to the Agnatha, or jawless fish. Early examples include Haikouichthys. During the late Cambrian, eel-like jawless fish called the conodonts, and small mostly armoured fish known as ostracoderms, first appeared. Most jawless fish are now extinct; but the extant lampreys may approximate

Cambrian (541–485 Ma): The beginning of the Cambrian was marked by the Cambrian explosion, the sudden appearance of nearly all of the invertebrate animal phyla (molluscs, jellyfish, worms and arthropods, such as crustaceans) in great abundance. The first vertebrates appeared in the form of primitive fish, which were subsequently greatly ...

Prehistoric fish are early fish that are known only from fossil records. They are the earliest known vertebrates, and include the first and extinct fish that lived through the Cambrian to the Quaternary. The study of prehistoric fish is called paleoichthyology.

Two jawless fish are known from the Early Cambrian. Myllokumingia had a head and trunk, a dorsal fin, a ventral fin (that might have been paired), 5-6 gill pouches, around 25 muscle segments (myomeres), a pharynx, an intestine, a notochord, and perhaps a pericardial cavity.

1999年11月4日 · Two fish-like animals from Early Cambrian rocks now fill this gap. Most major animal groups appear suddenly in the fossil record 550 million years ago, but vertebrates have been absent from...

1999年11月6日 · A DISCOVERY in China has pushed the age of the first fish back by more than 50 million years into the Cambrian period. The two small lamprey-like fish were found in 530-million- year-old...

Fishes, here defined as ‘non-digitate aquatic vertebrates’, first appear in the Cambrian Period at least 520 million years ago (Ma). They are first represented by fusiform taxa lacking well-developed fins and dermal bone covering.

1999年11月1日 · The first fossil chordates are found in deposits from the Cambrian period (545-490 million years ago), but their earliest record is exceptionally sporadic and is often controversial.

2019年10月6日 · Although most paleontologists wouldn't recognize them as true fish, the first fish-like creatures to leave an impression on the fossil record appeared during the middle Cambrian period, about 530 million years ago.

1999年11月4日 · The first chordate recorded from the Early Cambrian is the ceph-alochordate Yunnanozoon lividum from the 525 million-year-old Chengjiang fauna and predicts that other chordate clades (tunicates and craniates) had evolved by the Late Atdabanian, in the main burst of the Cambrian Explosion.