Phylogenetics Review
240 230 220 210 200 190 180 170 160 150 140 130 120 110 Millions of years ago
Eoraptor
Ornithischian dinosaurs
IV
111
Reduction
of IV and V
IV
Coelophysolds
Loss of V: II
and III about
the same length
Four digits
In hands
Allosaurids
Loss of IV
and V: II is
longer
Compsognathids
Hollow bones,
furcula (wish bone)
Pubic boot, three digits
Tyrannosauroids
In hand
Reduction
of III
Hollow cylindrical
feathers
Oviraptorosaurs
Tufted feathers
Dromeosaurids
Semillunate carpal in hand,
feathers dosed with barbules
and hooks, nest-brooding
Archaeopteryx
Feathers dosed and asymmetrical
III
Elongation
of 11
Long arms (uina longer than femur)
Toothless beak, fused wing
digits, short feathered tall
Living birds
A
Reduction of
I: fusion of
II and III;
loss of some
phalanges
Question 2
Which taxon is the outgroup the rest of the dinosaur clade shown here?
Living birds
Archaeopteryx
Eoraptor
Ornithischian dinosaurs
0/1 point
