Isalo II Formation | |
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Stratigraphic range: Ladinian-Carnian | |
Type | Geological formation |
Unit of | Isalo Group |
Underlies | Isalo III Formation (unconformity) |
Overlies | Isalo I Formation |
Lithology | |
Primary | Sandstone, mudstone |
Location | |
Coordinates | 20°18′S45°24′E / 20.3°S 45.4°E |
Approximate paleocoordinates | 23°06′S24°42′E / 23.1°S 24.7°E |
Region | Mahajanga & Toliara Provinces |
Country | Madagascar |
Extent | Morondava Basin, Mahajanga Basin |
Isalo II, also known as the Makay Formation, is an informal Triassic geological unit in Madagascar. [1]
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. [2]
Amphibians | ||
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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. [3] |
Stereospondyli indet. | Interclavicles | Indeterminate stereospondyl remains. May be from Isalo II or III. [3] |
Synapsids | ||
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Taxon | Material | Notes |
Archosauriformes sp. | Teeth, a coracoid, a centrum fragment, and cranial fragments | Various indeterminate fragments, some of which may belong to dinosaurs. [4] |
Azendohsaurus madagaskarensis [5] | Numerous skulls and postcranial fossils [1] | An allokotosaurian archosauromorph, [6] [7] [1] originally mistakenly identified as a "prosauropod" dinosaur. [5] |
Isalorhynchus genovefae | Numerous fossils representing parts of the skull and postcrania | A rhynchosaur sometimes considered a species of Hyperodapedon . [8] Possibly represents two taxa. [9] Reported sphenodontian [5] fossils are most likely juvenile rhynchosaurs instead. [10] |
Kongonaphon kely [11] | A maxilla and postcranial material | A tiny lagerpetid avemetatarsalian [12] |
Mambachiton fiandohana [13] | A partial skeleton | An armored basal avemetatarsalian [14] |
Phytosauria indet. | Teeth | Similar to Rutiodon teeth. [4] |
Procolophonidae sp. | A jaw fragment and other remains | An unnamed procolophonid parareptile [8] |
Pseudosuchia indet. | Osteoderms | Likely referable to stagonolepid aetosaurs, though similar to goniopholidid crocodylomorphs as well. [4] |
Silesauridae sp. | An unnamed silesaurid dinosauromorph [14] | |
Synapsids | ||
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Taxon | Material | Notes |
Chiniquodon kalanoro [15] | Part of a jaw | A chiniquodontid cynodont |
Dadadon isaloi [16] | Several skulls and jaw fragments [17] [18] | A massetognathine [18] traversodontid cynodont |
Kannemeyeriiformes sp. | An unnamed kannemeyeriiform dicynodont [5] [15] [1] | |
Menadon besairiei [16] | Skulls, jaws, and postcranial material [19] | A traversodontid cynodont |