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.

Fossil content

Amphibians

Amphibians
TaxonMaterialNotes
Metoposauridae indet.An interclavicle, skull fragments, and intercentraIndeterminate 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.InterclaviclesIndeterminate stereospondyl remains. May be from Isalo II or III.

Reptiles

Synapsids
TaxonMaterialNotes
Archosauriformes sp.Teeth, a coracoid, a centrum fragment, and cranial fragmentsVarious indeterminate fragments, some of which may belong to dinosaurs.
Azendohsaurus madagaskarensisNumerous skulls and postcranial fossilsAn allokotosaurian archosauromorph, originally mistakenly identified as a "prosauropod" dinosaur.
Isalorhynchus genovefaeNumerous fossils representing parts of the skull and postcraniaA rhynchosaur sometimes considered a species of Hyperodapedon. Possibly represents two taxa. Reported sphenodontian fossils are most likely juvenile rhynchosaurs instead.
Kongonaphon kelyA maxilla and postcranial materialA tiny lagerpetid avemetatarsalian
Mambachiton fiandohanaA partial skeletonAn armored basal avemetatarsalian
Phytosauria indet.TeethSimilar to Rutiodon teeth.
Procolophonidae sp.A jaw fragment and other remainsAn unnamed procolophonid parareptile
Pseudosuchia indet.OsteodermsLikely referable to stagonolepid aetosaurs, though similar to goniopholidid crocodylomorphs as well.
Silesauridae sp.An unnamed silesaurid dinosauromorph

Synapsids

Synapsids
TaxonMaterialNotes
Chiniquodon kalanoroPart of a jawA chiniquodontid cynodont
Dadadon isaloiSeveral skulls and jaw fragmentsA massetognathine traversodontid cynodont
Kannemeyeriiformes sp.An unnamed kannemeyeriiform dicynodont
Menadon besairieiSkulls, jaws, and postcranial materialA traversodontid cynodont