Prehistoric Fish

Prehistoric fish, as the term suggests, are those primitive fish species that are identified only through fossil data and archaeological evidences. As we all know, fish are the first forms of vertebrates existed on the planet, after which amphibians and the land animals evolved gradually. Hence, it is very intriguing to discuss the characteristics of ancient fish and how other advanced life forms have evolved from them. The branch of study that deals with prehistoric fish is referred to as paleoichthyology. In this article, we will talk regarding list of prehistoric fish and some species that are found alive.

Prehistoric Fish List

The first fish was thought to have existed in the Cambrian period of the Paleozoic era. Prehistoric fish include those species that survived from the Cambrian to the Tertiary period. Fossil records suggest that ostracoderms, jawless fish having shelled skin, were the earliest species that survived somewhere about 510 million years ago and they became extinct in the Devonian period. The jawed fish, placoderms followed them and thrived from the early Devonian to late Devonian period. Likewise, several fish species had appeared and diminished with passing time. Listed below are prehistoric fish, which are now extinct:

List of Jawless Fish

• Myllokunmingia
• Drepanaspis
• Arandaspis
• Boreaspis
• Haikouichthys
• Doryaspis
• Pteraspis
• Thelodus
• Tremataspis
• Hemicyclaspis
• Pharyngolepis
• Astraspis
• Errivaspis
• Dartmuthia
• Jamoytius

List of Placoderms and Acanthodians

• Pterichthyodes
• Bothriolepis
• Cretoxyrhina
• Coccosteus
• Dunkleosteus
• Cretoxyrhina
• Groenlandaspis
• Materpiscis
• Gemuendina
• Ctenurella
• Cheiracanthus
• Culmacanthus
• Ischnacanthus
• Acanthodes

List of Cartilaginous Fish

• Carcharocles megalodon
• Carcharocles angustidens
• Deltoptychius
• Cladoselache
• Heliobatis
• Helicoprion
• Cobelodus
• Ischyodus
• Otodus obliquus
• Sclerorhynchus
• Scapanorhynchus
• Hybodus
• Stethacanthus
• Squalicorax
• Spathobathis

List of Basal Ray-finned Fish

• Canobius
• Moythomasia
• Cheirolepis
• Aspidorhynchus
• Pycnodus
• Platysomus
• Semionotus
• Dapedium
• Palaeoniscum
• Saurichthys
• Perleidus
• Lepidotes

List of Modern Ray-finned Fish

• Sphenocephalus
• Enchodus
• Hypsidoris
• Hypsocormus
• Pholidophorus
• Knightia
• Protobrama
• Leptolepis
• Berycopsis
• Gyrosteus
• Thrissops
• Gryouchus
• Eobothus

List of Fleshy-lobed Fish

• Eusthenopteron
• Strunius
• Griphognathus
• Dipnorhynchus
• Gyroptychius
• Holoptychius
• Chinlia
• Osteolepsis
• Dipterus
• Macropoma

Prehistoric Fish Found Alive

Recently, extinct fish types are not included in prehistoric fish category, rather, they are studied under extinct fish. There are some prehistoric fish that are found alive, all of which are classified under living fossils. They are believed to be already extinct species, but found surviving till today. Such living fossils are very rare in occurrence and possess certain features similar to those of extinct forms. Following are some prehistoric fish identified much later from their evolution time.

Coelacanth
Scientific name Latimeria Chalumnae, living coelacanth was discovered for the first time in 1938 by a South African museum curator. The characteristic feature of this marine fish is the paired lobbed fins, which resemble legs in function. Considering this, coelacanth is considered to be the base organism for evolution of amphibians.

White Sturgeon
Sturgeon species is known to have evolved around 200 million years ago. It is the largest freshwater fish of those times, measuring about 20 feet length and weighing approximately 1,500 pounds. Sturgeon is popular for its dramatic jumps out of water, when threatened or hooked. With conservation programs, the population of white sturgeon increases to about 50,000.

Frilled Shark
A frilled shark was caught in Japan by a fisherman in 2007. Later, it was handed over to Japan's Awashima Marine Park. It is another rare prehistoric fish species that live in the deepest part of the ocean. Scientists are unaware as to why this bottom dwelling fish swim in the surface. Unfortunately, the fish died after a few hours, leaving the curiosity of scientists answered.

So, this was brief overview about prehistoric fish. According to scientists, Dunkleosteus terrelli was a giant prehistoric fish belonging to the placoderms. It had the most powerful jaws that any fish could have possessed. Be it the shark or huge crustacean, this marine beast gutted anything that came on its way. Taking its powerful jaws into consideration, dunkleosteus was believed to be the dominant predator in the Devonian period. However, scientists are unsure about its level in the food chain. The living fossils are the subject of common interest among scientists, eccentric explorers and crypto biologists.