chapter 27 ceratopsians Flashcards
(9 cards)
What is the key evolutionary novelty of all marginocephalia?
the presence
of a thickened bony shelf (margin) at the back of the skull
How does the thickened boney shelf present itself in ceratopsia and pachycephalosauria?
Ceretopsia: it makes a frill at the back of the head
Pachycephalosauria: it shows as a sort of dome
What are the key evolutionary novelties of ceratopsia?
-frill
- narrow beak with
flaring jugals
-rostral bone
where was the ceratopsian
Psitaccosaurus found? was it primitive or derived? and what time period was it found in?
-Mongolia, China and Siberia
-primitive
-Early cretaceous
What are the key evolutionary novelties of Neoceratopsia? and when and where were they abundant?
-abundant in the late cretaceous in North America
-an extremely large head
-broad and prominent frill
-pointed and sharply
keeled rostral bone
-limbs reflecting
quadrupedalism
when and where did Protoceratops live? what where some of its distinctive features?
-70-75 million years ago in Mongolia
- sexual dimorphism
-two large holes in the frill
when and where did Leptoceratops live? were some of its distinctive features?
what does its name mean?
-66.8-66 million years ago in Alberta and Wyoming
-name is little horned face
- it was an facultative biped
What are the key evolutionary novelties of ceratopsidae? and when were Ceratopsids found?
- Late cretaceous in North America
-larger more advanced - very large skulls (1 to 2.8 m skull length)
-large nasal openings
-prominent frills
-a variety of horns
-a dental battery
How do the two clades of ceratopsidae differ?
Give example species of each and state what their names mean.
- centrosaurinae: large nasal horn laking horns above the eyes, spikes going of the frill
Example: Centrosaurus
-Chasmosaurinae: large horns above the eyes and no large spikes on the frill
Example: Triceratops
