To install click the Add extension button. That's it.

The source code for the WIKI 2 extension is being checked by specialists of the Mozilla Foundation, Google, and Apple. You could also do it yourself at any point in time.

4,5
Kelly Slayton
Congratulations on this excellent venture… what a great idea!
Alexander Grigorievskiy
I use WIKI 2 every day and almost forgot how the original Wikipedia looks like.
What we do. Every page goes through several hundred of perfecting techniques; in live mode. Quite the same Wikipedia. Just better.
.
Leo
Newton
Brights
Milds

From Wikipedia, the free encyclopedia

Teleostomes
Temporal range: 445–0 Ma OrdovicianPresent
an acanthodian
Four species of bony fish
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Eugnathostomata
Clade: Teleostomi
C. L. Bonaparte, 1836
Subgroups

Teleostomi (from Greek τελεος, complete + Greek στόμα, mouth) is an obsolete taxon[1] of jawed vertebrates that supposedly includes the tetrapods, bony fish, and the wholly extinct acanthodian fish. Key characters of this group include an operculum and a single pair of respiratory openings, features which were lost or modified in some later representatives. The teleostomes include all jawed vertebrates except the chondrichthyans and the extinct class Placodermi.

Recent studies indicate that Osteichthyes evolved from placoderms like Entelognathus, while acanthodians are more closely related to modern chondrichthyes. Teleostomi, therefore, is not a valid, natural clade, but a paraphyletic group of species.[1]

The clade Teleostomi should not be confused with the similar-sounding infraclass Teleostei.

YouTube Encyclopedic

  • 1/1
    Views:
    35 174
  • Vertebrate Diversity: The Fish

Transcription

Origins

The origins of the teleostomes are obscure. They are traditionally assumed to be descendants of the Acanthodians ("spiny sharks") from the Early Silurian Period; however, more recent discoveries show that the "spiny sharks" are actually a paraphyletic assemblage leading to Chondrichthyes, and that placoderms like Entelognathus are more closely related to true bony fish.[1] Living teleostomes constitute the clade Euteleostomi, which includes all osteichthyans and tetrapods. Even after the acanthodians perished at the end of the Permian, their euteleostome relatives flourished such that today they comprise 99% of living vertebrate species.

Physical characteristics

Teleostomes have two major adaptations that relate to aquatic respiration. First, the early teleostomes probably had some type of operculum; however, it was not the one-piece affair of living fish. The development of a single respiratory opening seems to have been an important step. The second adaptation, the teleostomes also developed a primitive lung with the ability to use some atmospheric oxygen. This developed, in later species, into the lung and (later) the swim bladder, used to keep the fish at neutral buoyancy.[citation needed]

Acanthodians share with Actinopterygians the characteristic of three otoliths, the sagitta in the sacculus, the asteriscus in the lagena, and the lapillus in the utriculus. In dipnoans there are only two otoliths and in Latimeria there is only one.[2]

However, most of the above synapomorphies can ultimately be found in several chondrichthyan groups.[3]

Relationships

Gnathostomata
Teleostomi

References

  1. ^ a b c Zhu M, Yu X, Ahlberg PE, Choo B, Lu J, Qiao T, Qu Q, Zhao W, Jia L, Blom H, Zhu Y (October 2013). "A Silurian placoderm with osteichthyan-like marginal jaw bones". Nature. 502 (7470): 188–93. Bibcode:2013Natur.502..188Z. doi:10.1038/nature12617. PMID 24067611. S2CID 4462506.
  2. ^ Nelson, Joseph, S. (2006). Fishes of the World. John Wiley & Sons, Inc. ISBN 0-471-25031-7.{{cite book}}: CS1 maint: multiple names: authors list (link)
  3. ^ Pradel A, Maisey JG, Tafforeau P, Mapes RH, Mallatt J (May 2014). "A Palaeozoic shark with osteichthyan-like branchial arches". Nature. 509 (7502): 608–11. Bibcode:2014Natur.509..608P. doi:10.1038/nature13195. PMID 24739974. S2CID 3504437.
This page was last edited on 14 April 2024, at 12:56
Basis of this page is in Wikipedia. Text is available under the CC BY-SA 3.0 Unported License. Non-text media are available under their specified licenses. Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc. WIKI 2 is an independent company and has no affiliation with Wikimedia Foundation.