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The evolution of fish began about 530 million years ago during the Cambrian explosion. It was during this time that the early chordates developed the skull and the vertebral column, leading to the first craniates and vertebrates. The first fish lineages belong to the Agnatha, or jawless fish. Early examples include Haikouichthys.
They evolved from lobe-finned fish of the clade Sarcopterygii, appearing in coastal water in the middle Devonian, and giving rise to the first amphibians. [ 59 ] The group of lobe-finned fishes that were the ancestors of the tetrapod are grouped together as the Rhipidistia , [ 60 ] and the first tetrapods evolved from these fish over the ...
First vertebrates with true bones (jawless fishes). 450 Ma First complete conodonts and echinoids appear. 440 Ma First agnathan fishes: Heterostraci, Galeaspida, and Pituriaspida. 420 Ma Earliest ray-finned fishes, trigonotarbid arachnids, and land scorpions. [77] 410 Ma First signs of teeth in fish. Earliest Nautilida, lycophytes, and ...
Evolution and extinction of placoderms. The diagram is based on Michael Benton, 2005. [17] Dunkleosteus, among the first of the vertebrate apex predators, was a giant armoured placoderm predator. Amazichthys, a pelagic arthrodire from the Middle Famennian of the Late Devonian. Fin spine of Eczematolepis, from the Middle Devonian of Wisconsin
The evolution of tetrapods began about 400 million years ago in the Devonian Period with the earliest tetrapods evolved from lobe-finned fishes. [1] Tetrapods (under the apomorphy-based definition used on this page) are categorized as animals in the biological superclass Tetrapoda, which includes all living and extinct amphibians, reptiles, birds, and mammals.
Coelacanths (/ ˈ s iː l ə k æ n θ / ⓘ SEE-lə-kanth) (order Coelacanthiformes) are an ancient group of lobe-finned fish (Sarcopterygii) in the class Actinistia. [2] [3] As sarcopterygians, they are more closely related to lungfish and tetrapods (which includes amphibians, reptiles, birds and mammals) than to ray-finned fish.
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 . A few living forms, such as the coelacanth are also referred to as prehistoric fish, or even living fossils , due to their current rarity and similarity to ...
Tiktaalik (/ t ɪ k ˈ t ɑː l ɪ k /; Inuktitut ᑎᒃᑖᓕᒃ) is a monospecific genus of extinct sarcopterygian (lobe-finned fish) from the Late Devonian Period, about 375 Mya (million years ago), having many features akin to those of tetrapods (four-legged animals). [1]