Mawsoniidae
| Mawsoniidae | ||||||||||||
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Axelrodichthys araripensis |
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| Temporal occurrence | ||||||||||||
| Ladinian ( Middle Triassic ) to Cenomanian ( Upper Cretaceous ) | ||||||||||||
| 242 to 93.9 million years | ||||||||||||
| Locations | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Mawsoniidae | ||||||||||||
| Schultze , 1993 |
The Mawsoniidae are a coelacanth family that occurred from the Middle Triassic to the Upper Cretaceous . Fossils of the Mawsoniidae have been found in North and South America (Brazil, Chile) and in North (Morocco, Algeria, Egypt) and West Africa (Niger, Congo ). Because of the places where it was found, it is assumed that it is mainly distributed in western Gondwana . With the formation of the South Atlantic, the populations in Africa and South America were separated from each other. In contrast to most of the other coelaceans, including the recent Latimeria species, the Mawsoniidae lived in fresh waters and estuaries .
features
The Mawsoniidae had very different sizes. While Diplurus was rather small with lengths of 10 cm, Axelrodichthys represented a medium-sized fish with a length of about 40 cm, Mawsonia gigas was together with Megalocoelacanthus (family Coelacanthidae) the largest of all coelacanthidae and could be 3.5 to 4.5 in length Reach meters. A single Os quadratum suggests that there were even larger specimens.
Diagnostic features of the family are the long, ossified ribs and the wrinkled ornaments on the bone surfaces. The subopercular , part of the gill cover, is usually missing, as is the descending outgrowth of the supratemporal (skull bones), which can also only be reduced.
Genera
Five genera are definitely assigned to the family, and there are six other possible members (here with a question mark):
- Alcoveria ? (Triassic, Spain)
- Axelrodichthys (chalk, Madagascar)
- Chinlea (Triassic, Arizona & New Mexico)
- Diplurus (Triassic, Eastern North America)
- Garnbergia ? (Triassic, Germany)
- Indocoelacanthus ? (Jura, India)
- Libys ? (Jura, Germany)
- Lualabaea ? (Chalk, Morocco, Niger, Madagascar)
- Mawsonia (chalk, Algeria, Morocco, Brazil)
- Parnaibaia (Jura, Brazil)
- Trachymetopon ? (Jura, Germany)
Systematics
The Mawsoniidae are the sister group of the Latimeriidae , to which the two recent coelacanth species also belong, and form with them the suborder Latimeroidei. In contrast to the Mawsoniidae, the Latimeriidae lived and still live in the sea.
Individual evidence
- ^ A b Valéria Gallo, Marise Sardenberg Salgado de Carvalho, Hugo Ricardo Secioso Santos: New occurrence of † Mawsoniidae (Sarcopterygii, Actinistia) in the Morro do Chaves Formation, Lower Cretaceous of the Sergipe-Alagoas Basin, Northeastern Brazil. Bol. Mus. Para. Emilio Goeldi. Cienc. Nat., Belém, v. 5, n. 2, p. 195-205, maio-ago. 2010 PDF ( Memento of the original from January 20, 2015 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ^ Marise SS de Carvalho & John G. Maisey: New occurrence of Mawsonia (Sarcopterygii: Actinistia) from the Early Cretaceous of the Sanfranciscana Basin, Minas Gerais, southeastern Brazil. PDF
- ^ Karl Albert Frickhinger: Fossil Atlas Fish , Mergus-Verlag, Melle, 1999, ISBN 3-88244-018-X
- ^ A b Matías Soto, Marise SS De Carvalho, John G. Maisey, Daniel Perea & Jorge Da Silva: Coelacanth Remains from the Late Jurassic-? Earliest Cretaceous of Uruguay: The Southernmost Occurrence of the Mawsoniidae. Journal of Vertebrate Paleontology, 32 (3): 530-537. 2012. doi : 10.1080 / 02724634.2012.660899
- ^ Peter L. Forey: History of the Coelacanth Fishes. Springer Verlag GmbH, ISBN 0-412-78480-7
- ↑ Teruya Uyeno, Yoshitaka Yabumoto: Origin of Extant Coelacanths. PDF ( Memento of the original from February 27, 2012 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
