It is amongst the largest of all coelacanths, with one quadrate specimen (DGM 1.048-P) possibly belonging to an individual measuring 5.3 metres (17.4 feet) in length.

[6] The genus was named by Arthur Smith Woodward in 1907, from specimens found in the Early Cretaceous (Hauterivian) aged Ilhas Group of Bahia, Brazil.

[1] In Africa, they are known from the Continental Intercalaire of Algeria and Tunisia, the Ain el Guettar Formation of Tunisia, the Kem Kem Group of Morocco, and the Babouri Figuil Basin of Cameroon, spanning from the Late Jurassic, to early Late Cretaceous.

Fossils assigned to Mawsonia have also been found in Woodbine Formation of Texas, USA, then part of the island continent Appalachia.

It has been suggested that the denticles were used to crush hard shelled organisms (durophagy)[16] or that prey was swallowed whole using suction feeding.