Arganodus is an extinct genus of freshwater lungfish that had a wide global distribution throughout much of the Triassic period, with a single species surviving across Gondwana into the Cretaceous.[1] It is the only member of the family Arganodontidae, although it is sometimes placed in the Ceratodontidae or synonymized with the genus Asiatoceratodus.[2][3][4]
Indeterminate specimens have been found in the Redonda Formation, New Mexico and the Cumnock Formation, North Carolina, although the North Carolinian specimens are smaller than most recorded specimens.[9][10][11] Other indeterminate remains are also known from the Late Triassic of India and Turkey.[4] Possibly the oldest records of the genus are probable remains from the Induan of northwestern Australia.[4] It has been suggested that shortly after the origin of Arganodus in the early Triassic, it spread into what is now Europe, evolving into A. multicristatus. Before the Late Triassic, it diverged into two vicariant lineages separated by the Central Pangean Mountains: A. atlantis in the east, and A. dorotheae & the Cumnock species in the west, while going extinct in the European region. It eventually went extinct in Laurasia, but one species, A. tiguidensis, managed to survive in Gondwana throughout the Jurassic and Cretaceous.[4]
Kemp (1998) placed Arganodus as a synonym of Asiatoceratodus, and this taxonomy has been followed by many other authors, although others still retain them as different genera and families.[3][4]
Paleoecology
Arganodus was probably similar to modern lungfish, and lived in underwater burrows during dry periods until monsoons occurred.[6]
^ abcdefSkrzycki, Piotr; Niedźwiedzki, Grzegorz; Tałanda, Mateusz (2018). "Dipnoan remains from the Lower-Middle Triassic of the Holy Cross Mountains and northeastern Poland, with remarks on dipnoan palaeobiogeography". Palaeogeography, Palaeoclimatology, Palaeoecology. 496: 332–345. Bibcode:2018PPP...496..332S. doi:10.1016/j.palaeo.2018.01.049. ISSN0031-0182.
^Martin, M. (1979). "Arganodus atlantis et Ceratodus arganensis, deux nouveaux Dipneustes du Trias supérieur continental marocain [Arganodus atlantis and Ceratodus arganensis, two new dipnoans from the continental Moroccan Upper Triassic]". Comptes Rendus de l'Académie des Sciences de Paris. 289: 89–92.
