Isalo II, also known as the Makay Formation, is an informal Triassic geological unit in Madagascar.
It is described as "thick beds of mottled red or green clays associated with soft cross-bedded sandstones, light in colour and much finer-grained than the Isalo I sandstones." It is prominent in the Makay Massif.Brenon, P. (1972). The Geology of Madagascar. In: Battistini, R., Richard-Vindard, G. (eds) Biogeography and Ecology in Madagascar. Monographiae Biologicae, vol 21. Springer, Dordrecht. https://doi.org/10.1007/978-94-015-7159-3_2
Fossil content Amphibians Amphibians Taxon Material Notes Metoposauridae indet. An interclavicle, skull fragments, and intercentra Indeterminate metoposaurid remains similar to those of Indian metoposaurids. Some fossils were the basis for the dubious species "Metoposaurus hoffmani". May be from Isalo II or III. Stereospondyli indet. Interclavicles Indeterminate stereospondyl remains. May be from Isalo II or III.
Reptiles Synapsids Taxon Material Notes Archosauriformes sp. Teeth, a coracoid, a centrum fragment, and cranial fragments Various indeterminate fragments, some of which may belong to dinosaurs. Azendohsaurus madagaskarensis Numerous skulls and postcranial fossils An allokotosaurian archosauromorph, originally mistakenly identified as a "prosauropod" dinosaur. Isalorhynchus genovefae Numerous fossils representing parts of the skull and postcrania A rhynchosaur sometimes considered a species of Hyperodapedon. Possibly represents two taxa. Reported sphenodontian fossils are most likely juvenile rhynchosaurs instead. Kongonaphon kely A maxilla and postcranial material A tiny lagerpetid avemetatarsalianMambachiton fiandohanaA partial skeletonAn armored basal avemetatarsalian Phytosauria indet. Teeth Similar to Rutiodon teeth. Procolophonidae sp. A jaw fragment and other remains An unnamed procolophonid parareptile Pseudosuchia indet. Osteoderms Likely referable to stagonolepid aetosaurs, though similar to goniopholidid crocodylomorphs as well. Silesauridae sp. An unnamed silesaurid dinosauromorph
Synapsids Synapsids Taxon Material Notes Chiniquodon kalanoro Part of a jaw A chiniquodontid cynodont Dadadon isaloi Several skulls and jaw fragments A massetognathine traversodontid cynodont Kannemeyeriiformes sp. An unnamed kannemeyeriiform dicynodont Menadon besairiei Skulls, jaws, and postcranial material A traversodontid cynodont
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