Palaeos: Palaeos Amniota
The Vertebrates Dendrogram

Amniota: Dendrogram

Abbreviated Dendrogram
REPTILIOMORPHA
|
`--AMNIOTA
    |--Casineria
    |--Westlothiana
    `--Crown Amniota
       |--Sauropsida (= Reptilia)
       |  |--ANAPSIDA
       |  `--EUREPTILIA 
       `--SYNAPSIDA
Contents

Overview
Stem Amniota
Crown Amniota
Reptiles
Sauropsida
Dendrogram
References


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

checked ATW050518, new page MAK111106, revised 120321