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Fishes are a paraphyletic group and for this reason, the class Pisces seen in older reference works is no longer used in formal taxonomy.Traditional classification divides fish into three extant classes (Agnatha, Chondrichthyes, and Osteichthyes), and with extinct forms sometimes classified within those groups, sometimes as their own classes: [1]
As of September 2016, the International Union for Conservation of Nature (IUCN) lists 65 extinct fish species, 87 possibly extinct fish species, and six extinct in the wild fish species. [ 1 ] [ 2 ] Cartilaginous fish
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An inexplicable virus with symptoms of delusions, hallucinations, paranoia, and ultimately death, which affects humans and birds and brings the world close to the brink of extinction while allowing insects to overpopulate. The illness is named after the first few cases, where the infected, lost in daydream-like hallucinations, wandered into ...
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.
A second extinction pulse, the Hangenberg event closed the Devonian period and had a dramatic impact on vertebrate faunas. Placoderms mostly became extinct during this event, as did most members of other groups including lobe-finned fish, acanthodians and early tetrapods in both marine and terrestrial habitats, leaving only a handful of survivors.
The list includes all commonly accepted genera, but also genera that are now considered invalid, doubtful (nomina dubia), or were not formally published (nomina nuda), as well as junior synonyms of more established names, and genera that are no longer considered agnathans. Modern forms are excluded from this list.
Acropholis stensioei (fossil at the Geological Museum in Copenhagen) is a taxon referred to Palaeonisciformes based on superficial resemblance with Palaeoniscum. The systematics of fossil and extant fishes has puzzled ichthyologists since the time of Louis Agassiz, who first grouped all Palaeozoic ray-finned fishes together with Chondrostei (sturgeons, paddlefishes), gars, lungfishes, and ...