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
In tubeheaded forms, hollow crests are present in the skull and their beak is