The genus was named after the locality Bobasatrana (near Ambilobe) in northeast Madagascar, from where the type species, Bobasatrania mahavavica, was described. The name of this species refers to the Mahavavy River.[4]
Bobasatrania mahavavica fossilFossil of Bobasatrania canadensis (AMNH 6210)Bobasatrania groenlandica slab and counterslab fossils at the Geological Museum in CopenhagenBobasatrania ceresiensis fossil at Paleontological Museum, University of Zürich
†B. ladina (Accordi, 1955) - Latest Permian or earliest Triassic of Italy
†B. mahavicaWhite, 1932 - Early Triassic of Madagascar
†B. moroderi (Accordi, 1955) - Latest Permian of Italy (possibly conspecific with B. antiqua)
†B. nathorsti (Stensiö, 1921) - Earliest Triassic of Svalbard
†B. scutata (Gervais, 1852) - Middle Triassic (late Ladinian) of Germany and France
Remains of indeterminate species are known from the earliest Triassic of both Australia (found via drill core) and the Salt Range of Pakistan, as well as the later Early Triassic of the US states of Nevada and Idaho.[2]
The remains of a "Platysomus"-style tooth plate known from the latest Carboniferous or earliest Permian of the United States appear to be the earliest record of a Bobasatrania relative.[2]
Occurrence
Bobasatrania probably originated during the Lopingian (late Permian) epoch, survived the Permian-Triassic extinction event, and underwent a speciation event during the Triassic in the shallow coastal waters off the Pangaean supercontinent. Their fossils are therefore found across the globe (Canada, France, Germany, Greenland, Italy, Madagascar, Spitsbergen, Pakistan, Switzerland, United States).[2][5][6] Some of the best examples are known from the Wapiti Lake region of British Columbia, Canada.[7] The geologically oldest fossils are from the latest Permian Bellerophon Formation of Italy, while the youngest are from the late Ladinian Muschelkalk of Germany and France. Fossils include complete specimens but also isolated, characteristic tooth plates.[2]
Appearance
They have a distinctive diamond-shaped body, forked tail and long thin pectoral fins. B. ceresiensis was about 25 cm (9.8 in) long,[8] while other species, such as B. canadensis, grew to about 1.2 m (3.9 ft) in length or larger.[9][10] The structure of their teeth (tooth plates) suggests they fed on shelled animals.
^Bürgin, Toni (1992). "Basal ray-finned fishes (Osteichthyes; Actinopterygii) from the Middle Triassic of Monte San Giorgio (Canton Tessin, Switzerland)". Schweizerische Paläontologische Abhandlungen. 114: 1–164..
^Russell, Loris S. (1951). "Bobasatrania? canadensis (Lambe), a giant chondrostean fish from the Rocky Mountains". Annual Report of the National Museum of Canada, Bulletin. 123: 218–224.
^Neuman, Andrew G. (2015). "Fishes from the Lower Triassic portion of the Sulphur Mountain Formation in Alberta, Canada: geological context and taxonomic composition". Canadian Journal of Earth Sciences. 52 (8): 557–568. Bibcode:2015CaJES..52..557N. doi:10.1139/cjes-2014-0165.
Further reading
Nielsen, Eigil. 1942. Studies on Triasslc Fishes from East Greenland. I. Glaucolepis and Boreosomus. Palaeozoologica Groenlandica. vol. I.
Nielsen, Eigil. 1949. Studies on Triassic Fishes from East Greenland. II. Australosomus and Birgeria. Palaeozoologica Groenlandica. vol. III. 204 Medd, fra Dansk Geol. Forening. København. Bd. 12. [1952].
Stensiö, E. A:EON, 1921. Triassic Fishes from Spitsbergen. Part I. Vienna.
Stensiö, E. 1932. Triassic Fishes from East Greenland. Medd. om Grønland, Bd. 83, Nr. 3.
Stensiö, E. 1947. The sensory Lines and dermal Bones of the Cheek in Fishes and Amphibians. Stockholm, Kungl. Sv. Vet. Akad. Handl., ser. 3, Bd. 22, no. 1.
Watson, D . M. S., 1928. On some Points in the Structure of Palaeonlscid and allied Fish. London, Zool. Soc. Proc, pt. 1.
