Palaeos		Diapsida
Vertebrates		Dendrogram

Diapsida: Dendrogram

AMNIOTA
|--SYNAPSIDA
`--SAUROPSIDA
   |--ANAPSIDA
   `==EUREPTILIA
        |
        `--DIAPSIDA
           |==Araeoscelida
           `--Neodiapsida
               |=="Younginiformes"
               `--+--Ichthyosauria
                  `--Sauria
                     |--LEPIDOSAUROMORPHA
                     `--ARCHOSAUROMORPHA

The following is an unfortunately rather uninformative dendrogram. On the one hand, little phylogenetic work has been done with groups like the Hupehsuchia who are shown with a flattened bush arrangement that one gets from simply translating a low-phylo information Linnaean taxonomy to a cladistically-based dendrogram without adding any new input. On the other hand, the extreme specialisations of some of these early taxa, and lack of widely applicable synapomorphies, render any actual cladistic analysis dubious to the extreme. Hence the placement of even higher grade taxa like the ichthyosaurs on this tree should be taken as tentative and provisional MAK111116

REPTILOMORPHA
|--SYNAPSIDA
`--+--ANAPSIDA
   `--+==EUREPTILIA
      `--o DIAPSIDA MH, ToL
          |==Araeoscelida (probably paraphyletic, i.e. Aeroscelida = Diapsida))
          |  |-- Spinoaequalis
          |  `--+-- Petrolacosaurus     
          |     `-- Araeoscelis
          `--o Neodiapsida MH
             |--Orovenator
             `--+--Lanthanolania
                 |--Youngina           " Younginiformes" (paraphyletic)
                 |--Thadeosaurus
                 `--+--o Tangasaurinae
                     |   |--Tangasaurus
                     |   `--+--Hovasaurus
                     |       `-- Acerosodontosaurus
                     `--+--Claudiosaurus
                         `--+--o Weigeltisauridae
                             |   |--Weigeltisaurus
                             |   `--Coelurosauravus
                             `--+--+--+--+--o Thalattosauria/Thalattosauriformes
                                 |   |   |   |--Askeptosauroidea
                                 |   |   |   |   |--Endennasaurus
                                 |   |   |   |   `--Askeptosauridae
                                 |   |   |   `--Thalattosauroidea
                                 |   |   |      |--+--Nectosaurus
                                 |   |   |      |  `--Xinpusaurus
                                 |   |   |      `--Thalattosauridae
                                 |   |   |         `--+--Thalattosaurus
                                 |   |   |           `--Claraziidae
                                 |   |   `?--o Saurosphargidae
                                 |   |        |--Saurosphargis
                                 |   |        `--Sinosaurosphargis
                                 |   `--ICHTHYOSAURIA
                                 |?--Omphalosaurus
                                 |?--o Hupehsuchia
                                 |     |--Hupehsuchus
                                 |     |--Nanchangosaurus
                                 |     |--Unnamed species (SSTM 5025)
                                 |     `--Unnamed species (V4070)
                                 `--o Sauria  MH
                                    |?--CHORISTODERA
                                    |--LEPIDOSAUROMORPHA
                                    `--ARCHOSAUROMORPHA

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