The Skull
Figure 4
a) CORYTHOSAURUS CASUARIES, with an extensive semicircular crest
b) PARASAUROLOPHUS WALKERI, with an extensive tubular crest
c) EDMONTOSAURUS REGALIS, crestless
d) LAMBEOSAURUS LAMBEI,with an anterior hollow crest and a small solid crest inclined backward
- The skull is used to distinguish the various species of hadrosaurs.
- The family HADROSAURIDAE can be broken down into two subfamilies
based on their skulls. LAMBEOSAURINES are characterized as "tube heads" and
HADROSAURINES are characterized as "flateheads".
Figure 5 & Figure 6
- In flatheaded forms, hollow crests are never present in the skull and their beak is relatively broad and
ducklike.
- In tubeheaded forms, hollow crests are present in the skull and their beak is
relatively narrow.
