5 km NE of d'Irato (Triassic to of Madagascar)

Where: Diana, Madagascar (13.4° S, 48.9° E: paleocoordinates 44.4° S, 41.5° E)

• coordinate estimated from map

• small collection-level geographic resolution

When: Middle Sakamena Formation (Sakamena Group), Induan to Induan (252.2 - 247.2 Ma)

• "All previously described tetrapod specimens from the Diego Basin have been collected from the 'Couches à Poissons et Ammonites' (Besairie 1971) suggesting that the material described herein also pertains to this horizon, though this cannot be stated with absolute certainty." The "Couches à Poissons et Ammonites" are equivalent to the Middle Sakamena Formation of the Morondava Basin. "Biostratigraphical correlations based on ammonite faunas indicate referral of the 'Couches à Poissons et Ammonites' to the local Gyronitien Stage (Besairie 1971), which is equivalent to the Induan Stage of the Lower Triassic. This conclusion is supported by comparisons between the vertebrate faunas of Madagascar and the African mainland, which suggest that the Middle Sakamena Formation is intermediate in age between the Lystrosaurus and Cynognathus Assemblage Zones (Battail et al. 1987). Palynological data is also consistent with these interpretations (Wescott and Diggens 1998)." (Ketchum & Barrett, 2004. Canadian Journal of Earth Sciences 41:1-8).

•"The presence of Magniestheria truempyi in the same formation (Shen et al., 2002) indicates an Early Smithian (Olenekian, Early Triassic) age by correlation with the well-constrained Triassic strata of the Germanic Basin (Kozur and Weems, 2010)." (Falconnet et al. 2010. Comptes Rendus Palevol 11:357-369)

•Given the conflicting suggestions of an Induan or early Olenekian age, an Induan–Smithian range is given here.

• bed-level stratigraphic resolution

Environment/lithology: deltaic; nodular siliciclastic sediments

• Fossils preserved in ironstone nodules

Size class: macrofossils

Preservation: mold/impression

Reposited in the MNHN

Primary reference: J.-P. Lehman. 1966. Nouveaux Stégocéphales de Madagascar. Annales de Paléontologie (Vertébrés) 52:117-139 [R. Butler/R. Butler]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 144083: authorized by Richard Butler, entered by Richard Butler on 30.04.2013

Creative Commons license: CC BY (attribution)

Taxonomic list

Osteichthyes
 Temnospondyli - Rhytidosteidae
Mahavisaurus dentatus n. gen. n. sp.
Mahavisaurus dentatus n. gen. n. sp. Lehman 1966 tetrapod
MNHN MAE3037, MAE3031a, b