Actinopterygii or the ray-finned fishes, constitute a class or subclass of the bony fishes. The ray-finned fishes are so called because their fins are webs of skin supported by bony or horny spines (“rays”), as opposed to the fleshy, lobed fins that characterize the class Sarcopterygii (lobe-finned fish). A – dorsal fin: B – fin rays: C – lateral line: D – kidney: E – swim bladder. Class Actinopterygii and Class Sarcopterygii. FishBase World Wide Web electronic publication. Accessed August 16, at http://www. Definition: The last common ancestor of Actinopterygii (ray-finned fish) and Sarcopterygii (lobe-finned fish). Osteichthyan Trends: Osteichthyes weren’t the first.
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Berliner Geowissenschaftliche Abhandlungen A 53 In Late Devonian vertebrate speciation, descendants of pelagic lobe-finned fish—like Eusthenopteron —exhibited a sequence of adaptations: Although the sister group relationship of Sarcopterygii and Actinopterygii is not controversial, the hypothesis that Cladistia including Polypteriformes is included in Actinopterygii has not been rigorously tested.
Cyclostomata Myxini hagfish Hyperoartia actinotperygii. The muscle mass came to insert on a coronoid process extending dorsally from the jaw. Arratia G Actinopterygian postcranial skeleton with special reference to the diversity of fin ray elements, and the prolem of identifying homologies.
Lance Grande and W. In Origin and Phylogenetic Interrelationships of Teleosts eds. Brachydegma was previously considered to be a paleoniscid 99 and Hurley et al.
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Single dorsal fin right. Body scales are reduced in thickness, with the vascular layer and ganoine reduced. I am a biologist specialized in ichthyology and ichthyopaleontology. After review of the specimens by one of us G. Gars and fossil relatives. Some are autapomorphic or convergent on crown actinopterygii E. Discussion Our analyses of ray-finned fish phylogeny employed 21 independent loci and broad taxon sampling within all lineages where multiple extant taxa exist.
Single exons were sequenced from each nuclear gene Table 1. Schematic of Cheirolepisa non-neopterygian and Amiaa neopterygian The mouth: Hedges SB, Kumar S, editors. Scale structure and systematics position.
If you really want to know, consult the technical literature. Osteichthyes, the group inclusive of ray-finned fishes Actinopterygii and lobe-finned fishes plus tetrapods Sarcopterygiicontains all extant vertebrates except chondrichthyans and agnathans, yet our understanding of phylogenetic patterns and divergence times of many early-branching lineages remains incomplete. In advanced bony fishes this connection is lost and the swim bladder is separate from esophagus. The hyomandibula and preopercular became roughly vertical, with the hyomandibula hinged to the neurocranium in such a way as to rotate laterally.
A new stem-neopterygian fish from the Middle Triassic of China shows the earliest over-water gliding strategy of the vertebrates. If you wish to download it, please recommend it to your friends in any social system.
Multi-locus phylogenetic analysis reveals the pattern and tempo of bony fish evolution
Cheirolepis canadensis from Wikipedia. Modified in some as a “swim-bladder” for hydrostatic control. Results Phylogenetic analysis Sequences were generated from 20 nuclear exons and 1 mitochondrial rRNA gene yielding 19, aligned nucleotide positions.
Within teleosts, our results place Elopomorpha as the earliest branching lineage among the teleosts, Osteoglossomorpha as the sister group to Clupeocephala. The resulting phylogenetic hypothesis and evolutionary time scale provide new insights on fish diversification and establish a framework for understanding their many evolutionary innovations.
The fossil record suggests these conditions persisted for up to 10 million years and that full biotic recovery did not occur until the Late Triassic Actinopteri and Neopterygii then diverge successively at roughly million year intervals Ma and Ma, respectively in the Xctinopterygii Mississippian epoch.
Sarcopterygii – Wikipedia
Molecular Phylogenetics and Evolution 2: This appears to be another case where short times separating divergence events result in reduced phylogenetic signal. Northcutt RG Lungfish neural characters and their bearing on sarcoptergian phylogeny. Watsonulus eugnathoidesa paraseminotid.