Week 3 - eating Flashcards
What’s the main way to determine a dino’s diet?
comparative anatomy
What are some general adaptions of herbivores?
- thin, rigid or leaf shaped teeth –> shearing
- broad flat teeth –> grinding
- long legs and necks –> browse in trees
What are some general adaptations of carnivores?
- sharp pointed teeth –> piercing
- shape hooked claws –> hold onto struggling prey
- teeth w serrated edges –> slice through flesh
- sharp teeth + strong round teeth + strong jaws –> puncture and rip flesh and crack bones
What is durophagy?
consumption of bones
what are frugivores and some adaptations?
eat primarily fruit
- beak = sharp and hooked –> rip and tear apart peals and husks of large tropical fruits
what are piscivores and some adaptations?
eat primarily fish
- tall, sharp, conical teeth that lack serrations –> spearing and holding onto fish
- long jaws –> snap shut quickly
- procumbent dentition = teeth at the front pointed forward at and angle –> allows front tips of the jaw to be used to impale fish
what are insectivores and some adaptations?
eat primarily insects
- sharp piercing teeth –> puncture the chitinous exoskeletons of insects
- weak jaws and reduced teeth (may have no teeth) –> swallow soft-bodied insects whole
- large spade-shaped claws + powerful short limbs –> digging
What are some general adaptations of omnivores?
- unspecialized beaks and teeth or variety of teeth with diff shapes (canines = carnivorous teeth; molars = herbivorous teeth)
What modern animals replace their teeth?
sharks and alligators
Describe teeth replacement in dinos
- when a old tooth is ready to be replaced, the root is reabsorbed
- new teeth grow in and push upwards on the old teeth
- after reabsorption, the crown is shed
What is resorption and why is it important?
resorption = chemical process by which a dino breaks down its old teeth and bones
allows minerals and nutrients to be reused
Why do herbivores have to replace their teeth more often?
teeth wore down faster due to grinding
when is a crown usually shed?
during feeding
how can we tell that a tooth was shed?
worn and lacks roots
why is digesting plant material difficult? how do animals digest it?
cellulose is tough to digest
animals require bacteria to help digest cellulose, and chewing food helps
what are dental batteries? what dinos have them? did it evolve indep or dep?
arrangements of densely packed teeth that collectively form a single, large chewing surface, found in hadrosaurs and ceratopsians (convergent evolution)
How would have sauropods used their guts?
as fermentation tanks - did not chew food, so more time the food stayed in the gut, the better
how did hadrosaurs use their dental batteries?
- chewing surface were angled down
- moved their jaws back and fourth and side to side
How did ceratopsians use their dental batteries?
teeth in jaw would have slid together like scissors
Why were dental batteries inset in the jaw (positioned close to the tongue)?
helped make room for large cheeks –> holding food
what structure covers the outside of teeth, and which is found inside teeth?
enamel = covers outside
dentine = inside the tooth
What kind of teeth did sauropods and ankylosaurs have? What was the consequence of this?
had simple teeth –> nip of vegetation, but only break down their food a little –> had extensive guts –> big rib cages to house the immensive GIT –> takes longer to get their energy + increase the volume of food that can be held in the GIT
name two herbivourous theropods, and describe how they chewed their food
oviraptosaurus and ornithomimids –> lacked teeth but have gastroliths in their rib cages
Describe how gastroliths work
gastroliths = small masses of little stones in gastric mills –> filled by swallowing pebbles –> help toothless animals chew their food via muscular contractions that grind the rocks together and against plants
describe dromeosaurs and give an example of one
theropods with thin tails supported by special rod-like projections of their caudual vertebrae + chevrons, e.g. velociraptor
describe the carnivorous adaptations of dromeosaurs and troodontids
- serrated teeth
- large sickle-shaped claw on each hind foot
- resemble retractable claws and could be raised off the ground
- keeping it raised –> keep the claw sharp
- slash and puncture prey, help some climb trees
Why are spinosaurs thought to be piscivores?
teeth are conical, have sharp tips and have few to no serrations
Describe alvarezsaurs and give an example of one
- theropod with short front limbs and compact hands
- insectivores –> reduced teeth + short but strong front limbs
- shivuuia –> one large spade-shaped claw on each hand
Describe the carnivoruous adaptations of tyrannosaurs
- teeth with serrated edges
- teeth have blunt tips –> attachment for jaw muscles –> increase bite force –> capable of durophagy
What are some non-morphological indicators of diet?
- cololites (fossil gut contents)
- gastroliths
- bite marks on bones
- corpolites (poopies)
