(named after J. Mawson?).
Named By: J. Mawson & A. S. Woodward - 1907.
Classification: Chordata, Sarcopterygii, Actinistia, Coelacanthiformes, Mawsoniidae.
Species: M. gigas (type), M. brasiliensis, M. lavocati, M. libyca, M. tegamensis, M. ubangiana.
Size: Up to 4 meters long, though isolated fossils suggest that rare individuals may have grown slightly larger than this.
Known locations: Fossils are mostly known from across South America and North Africa. Individual countries known to include Algeria, Brazil and Morocco.
Time period: Early Cretaceous.
Fossil representation: Numerous specimens ranging from partial remains to a few almost complete individuals. Fossils of the skull bones seem to be most common.
are one of the few creatures that typify animal life in the Mesozoic
that are still alive today. Modern coelacanths are represented by the
that live in the deep waters of the Indian Ocean, the
largest examples of which are known to easily attain lengths of two
meters. Back in the early Cretaceous however these fish would have
been small fry, with impressively large coelacanths of the Mawsonia
genus reaching lengths of up to four meters, double that of the
largest observed Latimeria. Because of their
large size, Mawsonia
are rarely preserved complete, and specimens which are preserved,
are usually of smaller individuals under three meters. Skull bones
are usually the most common specimens of Mawsonia
due to the greater
bone density increasing the likelihood of those parts surviving long
enough to fossilize.
Mawsonia like other coelacanths were probably predatory fish that would cruise over the sea floor snatching up fish and larger invertebrates that were sheltering in crevices amongst rocks and coral. We do not know for certain however if Mawsonia were nocturnal like the Latimeria coelacanths that we know today. Interestingly, Mawsonia may have been more inclined to stray into shallower waters than what Latimeria are known to. This is because most of the fossil bearing formations that Mawsonia are known from were estuarine and mangrove habitats back in the early Cretaceous.
When fully grown to such a large size, Mawsonia may have had few predators, though larger sharks, pliosaurs and perhaps even spinosaurid dinosaurs, may have still been potential dangers for Mawsonia.
- On the Cretaceous formation of Bahia (Brazil), and on vertebrate fossils collected therein. Quarterly Journal of the Geological Society of London 63:128-139 - J. Mawson & A. S. Woodward - 1907.
- Un nouveau Coelacanthidé du Crétacé inférieur du Niger, remarques sur la fusion des os dermiques [A new coelacanth from the Lower Cretaceous of Niger, remarks on fusion of the dermal bones]. - Colloques Internationaux du Centre National de la Recherche Scientifique, Paris, 1973. Problèmes actuels de Paléontologie (Évolution des Vertébrés). Centre National de la Recherche Scientifique 218:175-190. - S. Wenz - 1975.
- Coelacanths from the Lower Cretaceous of Brazil. American Museum novitates ; no. 2866. - John G. Maisey - 1986.
- A new coelacanth from the Early Cretaceous of Brazil (Sarcopterygii, Actinistia). - Paleontological Research 6: 343-350. - Yoshitaka Yabumoto -2002.
- New mawsoniid coelacanth (Sarcopterygii: Actinistia) remains from the Cretaceous of the Kem Kem beds, Southern Morocco - In Mesozoic Fishes 3 – Systematics, Paleoenvironments and Biodiversity, G. Arratia & A. Tintori (eds.): pp. 493-506, 7 figs. - Lionel Cavin & Peter L. Forey - 2004.
- New materials of a Cretaceous coelacanth, Mawsonia lavocati Tabaste from Morocco. - Bulletin National Science Museum Tokyo C 01/2005; 31:39-49. - Yoshitaka Yabumoto & Teryua Uyeno - 2005.
- New occurrence of Mawsonia (Sarcopterygii: Actinistia) from the Early Cretaceous of the Sanfranciscana Basin, Minas Gerais, southeastern Brazil. - Geological Society, London, Special Publications 01/2008; 295(1):109-144. DOI: 10.1144/SP295.8. - Marise S. S. de Carvalho & John G. Maisley - 2008.