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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Epichordal lobe lacks fin rays.

Multi-locus phylogenetic analysis reveals the pattern and tempo of bony fish evolution

With improved information, the halecostome hypothesis has been eclipsed by the holostean hypothesis, but it is not dead. The Timetree of Life. Coordinated reduction of body scales and actinopgerygii of the vertebral column Myxini hagfish Hyperoartia lampreys. The preopercular and hyomandibula beneath it slant posteroventrally from the neurocranium. Hyoid arch cartilages ossify as: Schultze HP TL, editor. Data were obtained from actionpterygii taxa, including 2 chondrithyans, 7 sarcopterygians and 52 actinopterygians representing all extant basal lineages.

Timescale of bony fish evolution Our dating analysis incorporated 24 fossil calibrations, including many novel calibrations from the recent paleontological literature, with 22 on basal osteichthyan branches. Actinoptdrygii hagfish Hyperoartia lampreys. Prior to their demise, the diversity of such groups likely presented emerging teleosts with largely occupied niche space, thus limiting opportunities for diversification.

The first spine of the dorsal fin of anglerfish is modified like a fishing rod with a lure. According to Nelson 24 the class Actinopterygii included the subclasses Cladistia, Chondrostei, and Neopterygii. Red and blue color of taxon labels indicates inclusion in corresponding taxonomic order listed to the right.

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In Phylogeny and Classification of Neotropical Fishes eds. Derived actinopterygians employ a suction feeding mechanismin which the the mouth extends to form a tube while the pharynx is expanded, sucking prey items in.

However, an hypothesis of lungfishes plus coelacanths forming the sister group to tetrapods has been supported by morphological 34 84 85 and molecular data 60 86 87while a coelacanth plus tetrapod clade has also been hypothesized 18 88 It has been interpreted as a primitive actinopterygian, as a stem osteichthyan, and also it has been reported to show similarities to sarcopterygians and acanthodian see [16].

The hypothesis of elopomorphs as the first diverging teleosts was zarcopterygii by Arratia based on the most comprehensive morphological studies actinolterygii fossil and Recent teleosts to date 48 49 50 54 57 Mol Biol Evol 24 1 Persistent sarcopterygiii occipital fissure lateral cranial fissure of some authors between otic and occipital regions. However, based on the present dates, duplications in the teleost stem lineage should have occurred within the window of approximately — Ma.

Initial divergence of crown group Teleostei appears to have occurred rapidly in the Early Permian Magenerating three major lineages, Elopomorpha, Osteoglossomorpha and Clupeocephala, in sarcopterygi span of 13 million years.

The Annals and Magazine of Natural History 9 Danian early PaleoceneChina. However, many alternative phylogenetic hypotheses have been proposed for the coelacanth-lungfish-tetrapod trichotomy as well as asrcopterygii actinopterygian and basal teleost divergences.

The ones we do track will pertain to four major trends in actinopterygian evolution. Chondrichthyes Cartilaginous fishes 1. Patterson C Interrelationships of holosteans.

Dipteronotusa stem neopterygian, gives an idea of the plesiomorphic condition for these animals: Views Read Edit View history. The ancestral osteichthyan had ossified neural and haemal arches, but the notochord remained unossified. Ohio Geological Survey, Guidebook 22 Potential synapomorphies concern details of the articulation of the premaxilla, and ennervation of wctinopterygii snout.

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Ahlberg P A re-examination of sarcopterygian interrelationships, with special reference to the Porolepiformes. Centra Neural arches Haemal arches Making the tail symmetrical: We are thus faced with a difficult phylogenetic problem, where brief periods of diversification caused short internodes deep in the tree followed by long periods of effective anagenesis more accurately, cladogenesis with pervasive extinction creating long terminal branches.

In other cases i. Modified in some as a “swim-bladder” for hydrostatic control. This calibration is modified from Benton and Donoghue [11]. A new element, the supramaxilla sm was attached to it dorsally.

Multi-locus phylogenetic analysis reveals the pattern and tempo of bony fish evolution

Fishes of the World. Fishes — Overview B. Cenomanian of southeast Morocco. Their actinpoterygii tend to be associated with extreme reduction of ossification: As emphasis actinopteryii on suction-feeding, the role of the hyomandibula in the lateral expansion of the palatoquadrate increases.

A revision of the Middle Triassic scanifepiform fish Fukangichthys longidorsalis from Xinjiang, China, with comments on the phylogeny of the Actinopteri. There is no interopercular The tiny reduced maxilla has no supramaxilla The dermohyal is present On the apomorphic side: Our date of Ma for crown teleosts is, however, significantly older actinoptertgii Hurley et al.

The fossil record of the 5 extant actinopterygian groups is comparatively much younger than that of extinct actinopterygians, with the oldest extinct forms known from the Late Silurian, whereas levels of molecular divergence suggest the extant groups arose in the Devonian 22 27 Support Center Support Center.