order Eurypterida
pistosaurid
aeolosaurid
skaracarid
acritolepid
neoichthyosaur
gyracanthid
anatoliadelphyid
nectridean
neoichthyosaurian
eumaniraptoran
acanthostegid
halecomorph
dolichosaurid
nothosaurid
cochliodont
aigialosaurid
eryopid
pleuropholid
ctenacanthiform
euomphalid
pycnodontid
chiltoniid
eriptychiid
kuehneosaur
Uintatheriidae
orthoceratoid
euparkeriid
stenopterygius
hymenochirin
archaeostracan
onychodontid
leptocleidid
choristodere
family Uintatheriidae
halisaurine
lophosteiform
Stenopterygius quadrisicissus
arctolepid
pituriaspid
placodont
pteraspidid
sibyrhynchid
aspidorhynchid
thunnosaur
aplanochytrid
phyllodontid
blochiid