Mawsoniidae
Axelrodichthys araripensis
- North & South America
- Africa
- Europe?
- India?
The Mawsoniidae are a family of coelacanth which occurred from the Middle Triassic to Upper Cretaceous. Fossils of Mawsoniidae were found in North and South America (Brazil, Chile) and North (Morocco, Algeria, Egypt ) and West Africa (Niger, Congo ). Due to the sites, especially the spread in the western Gondwana is assumed. With the emergence of the South Atlantic populations in Africa and South America were separated. In contrast to most other coelacanth Latimeria including the recent species which lived in freshwater and estuaries Mawsoniidae.
Features
The Mawsoniidae had very different sizes. While Diplurus with lengths of 10 cm was rather small, represented Axelrodichthys with a length of about 40 cm a medium sized fish, Mawsonia gigas was with Megalocoelacanthus (Family Coelacanthidae ) the greatest of all the coelacanth and was a length of 3.5 to 4.5 achieve meters. A single Os quadratum suggests that there were larger specimens.
Diagnostic characters of the family are the long, ossified ribs and the wrinkled ornaments on the bone surfaces. The Suboperculare, part of the gill cover, normally absent, as the descending outgrowth of the supratemporal ( skull bones), which can also be reduced but only.
Genera
Five genera are attributed with certainty to the family, and there are six other potential members (indicated by a question mark ):
- Alcoveria? ( Triassic, Spain)
- Axelrodichthys ( Cretaceous, 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 )
System
The Mawsoniidae are the sister group of the Latimeriidae, which include the two recent Quastenflosserarten, and form with them the subordination Latimeroidei. In contrast to the Mawsoniidae lived and live the Latimeriidae in the sea.