Question | Answer |
Marginocephalians belong to what group? | Ornithiscians |
What 2 groups are the marginocephalians split into? | Pachycephalsauria (dome, bone-headed) & Ceratopsia (horned) |
Early characteristics of the marginocephalians? | small-bodied and bipedial |
What does "marginocephalian" mean? | margin-headed |
Which of the two groups of marginocephalia are from the cretaceous of Europe, Asia, and N. America? Also they are found sparsely IF found. | Pachycephalosaurus |
Other group: Very successful, found in abundant remains in the late cretaceous of N. America and Asia | Ceratopsians |
Pachycephalosaurs Anatomy: (mr. burns dinosaur) | Thickened skull domes (thickened frontals and parietals), bipedal, leaf-shaped/serrated teeth |
Ceratopsians anatomy: | Frill (made from parietals and squamosal bones), horns |
Who is the oldest ceratopsian? | Yinlong |
Which ceratopsian is small-bodied, bipedal, and nicknamed the "parrot-lizard"? | Psittacosaurs |
Group of mid-sized ceratopsians who are thought to be bipedal while others of this same group were quadrupedal? | Protoceratopsids |
Compare protoceratopsids to psittacosaurs | protoceratopsids possess longer frills but were shorter. Some had a nasal bump (not a horn). Teeth were more advanced. |
Were all ceratopsids considered bipedal? | No, they were all quadrupedal. |
What kind of teeth system did ceratopsids possess? | Complex dental batteries (continuous surface of teeth that were placed in rows so teeth were present when the new were replacing the old.) |
What hypotheses have been made about the dome head of the pachycephalosaur? | Head-butting, flank butting, sexual or intraspecific display |
What has been found in ceratopsians for processing food? | Gastrolith, or a gizzard |
What has there been much controversy about as far as the ceratopsian's movement? | Posture and gait of ceratopsids |
What hypotheses have been made about ceratopsian horns and frills? | Expanded surface for attachment of large jaw muscles, protection, thermoregulation. The strongest being that the frill is used for display. |
What indicates that ceratopsids traveled in herds? | Large quantities of ceratopsids in one bonebed. |