Ichthyodectiformes

Ichthyodectiformes
Thrissops cf. formosus
Temporal occurrence
Kimmeridgian (Upper Jurassic) to Maastrichtian (Upper Cretaceous)
157.3 to 66 million years
Locations
Worldwide
Systematics
Sub-stem : Vertebrates (vertebrata) Superclass : Jaw mouths (Gnathostomata) Class : Ray fins (Actinopterygii) Subclass : Neuflosser (Neopterygii) Subclass : Real bony fish (Teleostei) Order : Ichthyodectiformes
Scientific name
Ichthyodectiformes
Bardack & Sprinkle , 1969

The Ichthyodectiformes are an extinct order of bony fish (Osteichthyes). They lived from the Middle Jurassic to the Upper Cretaceous , most of the species in the sea, some also in brackish or fresh water .

features

Some Ichthyodectidae: 1 Xiphactinus audax , 2 Ichthyodectes ctenodon , 3 Cladocyclus gardneri , 4 Chirocentrites coronini

The fish differ from all other real bony fish (Teleostei) by the structure of the tail fin skeleton and a special bone called ethmopalatinum in the floor of the nasal pit . Their caudal fin is large and deeply forked, typical of fast open water hunters ( pelagic ). Most genera have a long anal fin with 24 to 37 fin rays . The dorsal fin sits far back, opposite the anal fin.

The Ichthyodectiformes were predatory fish that had long conical fangs in their jaws . The members of the Ichthyodectidae family were sometimes very large, Gillicus reached lengths of 1.5 meters, Ichthyodectes was 2.2 meters long and Xiphactinus audax was over four meters long.

Systematics

The Ichthyodectiformes among the Neuflossern (Neopterygii) and by the American ichthyologists Joseph S. Nelson with the recent , living in fresh water, Knochenzünglerartigen (Osteoglossiformes) and moon eyes (hiodontiformes) in the group of Knochenzünglerähnlichen asked (Osteoglossomorpha). The monophyly of the Ichthyodectiformes is uncertain.

There are five families:

• Allothrissopidae
• Cladocyclidae
• Ichthyodectidae
• Occithrissopidae
• Saurodontidae

literature

• Joseph S. Nelson : Fishes of the World. 4th edition. John Wiley & Sons, Hoboken NJ et al. 2006, ISBN 0-471-25031-7 .
• Robert Lynn Carroll : Paleontology and Evolution of the Vertebrates , Thieme, Stuttgart (1993), ISBN 3-13-774401-6
• Karl Albert Frickhinger: Fossil Atlas of Fishes. Mergus, Verlag für Natur- und Heimtierkunde Baensch, Melle 1999, ISBN 3-88244-018-X .
• John A. Long: The Rise of Fishes . The Johns Hopkins University Press, 1995, ISBN 0-8018-4992-6

Web links

Commons : Ichthyodectiformes  - collection of images, videos and audio files

• Mikko's Phylogeny Archive Ichthyodectiformes