Palaeos: | ![]() |
Amniota |
The Vertebrates | Dendrogram |
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Abbreviated Dendrogram
REPTILIOMORPHA | `--AMNIOTA |--Casineria |--Westlothiana `--Crown Amniota |--Sauropsida (= Reptilia) | |--ANAPSIDA | `--EUREPTILIA `--SYNAPSIDA |
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This is surely one of the smaller dendrogram pages on Palaeos, as not much is known regarding stem amniotes. We have tentatively placed Casineria and Westlothiana here, as they fit the expected pattern of miniaturisation combined with advanced amniote features, but they could just as easily as easily go among the Reptiliomorpha. Most cladistic analyses actually place those two taxa beneath the diadectomorphs (almost certainly amphibians) and Solenodonsaurus, leaving the amniote ancestor unknown; the present author considers this could also be an artifact of diadectmorph convergence with early reptiles; as with multiple mammal-like lines of therapsids and bird-like lines of coelurosaurs there were clearly a number of lineages indepedently evolving in the same direction. MAK120321
REPTILIOMORPHA | `--AMNIOTA |--Casineria •X |--Westlothiana •X `--Crown Amniota MH, ToL|--+--Sauropsida MH / Reptilia | |--ANAPSIDA | `--EUREPTILIA `--SYNAPSIDA
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checked ATW050518, new page MAK111106, revised 120321