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