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Lecture 13 Wrld Dnsr
Horn-heads and dome-heads
|Marginocephalians belong to what group?
|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?
|Which of the two groups of marginocephalia are from the cretaceous of Europe, Asia, and N. America? Also they are found sparsely IF found.
|Other group: Very successful, found in abundant remains in the late cretaceous of N. America and Asia
|Pachycephalosaurs Anatomy: (mr. burns dinosaur)
|Thickened skull domes (thickened frontals and parietals), bipedal, leaf-shaped/serrated teeth
|Frill (made from parietals and squamosal bones), horns
|Who is the oldest ceratopsian?
|Which ceratopsian is small-bodied, bipedal, and nicknamed the "parrot-lizard"?
|Group of mid-sized ceratopsians who are thought to be bipedal while others of this same group were quadrupedal?
|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.