thalattosuchian
cochliodont
aspidorhynchid
pygocephalomorph
order Eurypterida
aigialosaurid
Eurypterida
palaeobatrachid
Arachnida
family Uintatheriidae
eutriconodontan
arthropod genus
Uintatheriidae
class Arachnida
tanystropheid
phoebodontiform
polyglyphanodontian
palaeonisciform
pycnodontiform
order Sauropterygia
arthropleurid
pistosauroid
thalattosaur
Ictodosauria
Sauropterygia
stryacocephalid
euomphalid
sea scorpion
choristoderan
therapsid
order Ictodosauria
anomocarid
Stenopterygius quadrisicissus
opisthodontian
petalodontiform
mammaliamorph
anamorphosis
gyracanthid
stenopterygius
bystrowianid
polydolopimorphian
dissorophid
semionotiform
Sisyridae
family Sisyridae
phoebodont
ankylopollexian
Belemnoidea
nothosaur
dinornithiform