Week 7 Theropods 1 Flashcards
What is the difference in hip bones between Saurischian and Ornithischian dinosaurs?
Explain how theropods stood and walked/ran and what fossil evidence supports that?
Theropods had narrow legs, walked one foot in front of the other (small gait), horizontal head and tail balanced over pelvis. Tracks/ imprints in fossilized ground supports this hypothesis.
How many digits were in the footprints of different theropods?
3 digits were most common, 4 digits in more primitive theropods
Were theropod arms useless? What could they have been used for?
MIGHT be used for mating and grasping prey
Differentiate carnivore and herbivore skulls using their size and shape
Carnivores had bigger heads w/ a bigger mandible for stronger bites.
Herbivores had smaller, narrower skulls for lightweight head and for further reach when eating vegetation.
What are a few characteristics that separate carnivore teeth from herbivore teeth?
Carnivore teeth had serrated blade-like teeth for slicing and holding prey in mouth.
Herbivore teeth would either be more pencil like at the tip with space in between teeth for grab and gulp method or flat w/ wear on their teeth from grinding and chewing.
Compare the vision of different dinosaurs and what fossil evidence supports this comparison?
Carnivores had eyes facing forward (can see in 3D)
—> had shortned snouts to help increase range
Herbivores had eyes on sides of head for better view of surroundings (can’t see in 3D)
—> Fossil evidence is shown in the positioning and size of orbit in skull
What are some reasons for different morphs in the same species? Why is this a problem for paleontologists?
Environnmental adaptations, Ontogenic changes, Sexual dimorphism.
—> issue for paleontologists because they can misclassify a species or get confused w/ growth stages.
What is the encephalization quotient and what does it tell us about intelligence in different types of theropods?
EQ is the estimate of an animal’s brain size compared to the brain size predicted for it’s body mass.
—> Theropods w/ higher EQ have more complex behaviours and cognitive abilities. For ex: birds are very intelligent for their large brain compared to their small body.
Define sexual dimorphism
The difference in appearance (colour, shape, size, structure) between males and females of the same species
What is the general pattern of feather evolution in dinosaurs and what were the different types used for?
Possible uses: insulation, display for colour and shape —> to attract a mate, flying?
What are the leading hypothesis for the origin of flight in dinosaurs?
- Tree-down -> climbing and gliding.
- Ground-up -> running and leaping
- The Compromise -> started by helping them run up
