Oryctos
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Accès privé :
| volume 2, 1999 |
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Michel Martin, Laurent Barbieri & Gilles Cuny, The Madagascan Mesozoic ptychoceratodontids (Dipnoi) : systematic relationships and paleobiogeographical significance. Oryctos 2, 3-16.
The Mesozoic continental deposits of Madagascar have yielded a lot of Dipnoan tooth plates which have been described a long time ago, on the bases of new data they are revised inside. Dipnoan tooth plates yielded by the madagascan continental Upper Triassic are referred to Ptychoceratodus cf. hislopianus and to P. acutus. These species are closely related to P. hislopianus and to P. virapa respectively (continental Late Triassic, India). They possess an obtuse inner angle on the tooth plates which could be an apomorphic character. These species provide evidences for good terrestrial connection between Madagascar and India during the Late Triassic. The Late Cretaceous lungfish cf. Ferganaceratodus madagascariensis is related to a special group of ptychoceratodontids worldly recorded since the Late Triassic (apart from Africa), frequently these ptychoceratodontids do not show a clear apex of the inner angle on the tooth plates. In the Late Cretaceous these latter ptychoceratodontids have no longer paleogeographical significance. During the Mesozoic they are recorded everywhere apart from Africa and several landroutes are possible in order to explain their distribution during the Late Cretaceous.
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