Mammalian structure and function: Feeding Flashcards
Describe dentition
- enamel wears away with age (more dentine exposed)
- tooth position
- incisors
- canines
- [diastema]
- premolars
- molars
Describe tooth morphology
- crown
- gum line
- root
- enamel
- dentine
- pulp cavity
- root canal
- cementum
Compare and contrast carnivores and predators
- position of mandibular condyle
- primary chewing muscles
- temporalis in carnivores
- masseters in herbivores
Describe molar teeth
- omnivore: crushing (hard, brittle or turgid)
- carnivore: shearing (soft, tough)
- herbivore: grinding (tough, fibrous)
Describe herbivore feeding
- occlusal surfaces
- bunodont (pig)
- lophodont; cusps in transverse ridges (African elephant)
- selenodont (deer) crescent-shaped ridges
Describe the white-tailed deer dentition
- lower incisors show lateral incisiform canines
When did teeth differentiate?
Mesozoic
List some mammalian trophic groups
- Insectivorous
- Carnivorous
- Herbivorous
- Omnivorous
Describe different mammalian feeding specialisations from the basal insectivore (hedgehog)
- mollusc specialists (walrus)
- specialised insectivores (mole, armadillo, anteater, giant anteater)
- plankton specialists (right whale)
- fish and squid specialists (porpoise)
- nectar specialists (nectar-eating bat)
- fruit specialists (fruit-eating bat)
- omnivores (bear, peccary, marmoset)
- grazing and browsing herbivores (horse, deer)
- gnawing herbivores (jackrabbit, woodrat)
- carnivores (mountain lion, coyote, raccoon)
Describe insectivory
- basal condition of Eutheria
- nine mammalian orders (Monotremata; Carnivora, aardwolf)
Describe insectivory Tamandua
- tongue specialisation (long, vermiform)
- anchored to the sternum
- can be protruded extensively to catch ants and termites
Describe the tongue of Tamandua
- tongue muscle divided
- mandible weak, toothless
- tongue cylindrical, sticky
- salivary gland (large!)
- tongue anchored to posterior end of sternum
Describe the digestive system of herbivores
- stomach
- anus
- short intestine, no caecum
- short-tailed shrew
Describe the digestive system of carnivores
- oesophagus
- stomach
- caecum
- anus
- short intestine and colon
- small caecum
- ref dox
Describe the digestive system of non ruminant herbivores
- simple stomach
- large caecum
- anus
- black-tailed jackrabbit
Describe the digestive system of ruminant herbivores
- esophagus
- large rumen
- reticulum
- abomasum
- omasum
- caecum
- anus
- four chambered stomach
- long small and large intestine
- e.g. mule deer
Describe convergent burrowing
- placental mole
- marsupial mole
Describe convergent anteating
- anteater
- numbat
Describe mouse conversion
- mouse
- marsupial mouse
Describe convergent climbing
- lemur
- spotted cuscus
Describe convergent gliding
- flying squirrel
- flying phalanger
Describe convergent felinism
- bobcat
- Tasmanian tiger cat
Describe convergent wolfism
- wolf
- tasmanian wolf
Describe Carnivory
- terrestrial carnivores
- aerial carnivores
- aquatic carnivores
Describe vampire bats
blade-like upper incisors
Describe baleens
filter-feeders
Give an aerial carnivore
vampire bats
Give an aquatic carnivore
baleens
Describe the Canidae
- wounding bite (African wild dog)
- puncturing grip (side-striped jackal)
- rapid champing (bat-eared fox)
Describe the relationship between carnivore and prey mass
strong linear positive correlation
Describe feeding on ecological systems
- mob operators
- middle way groupers
- spatial groupers
Describe ruminants
foregut fermentation
Hindgut fermentation
- monogastric system
- characteristic of perissodactyls
- horses, zebras, asses, tapirs, rhinoceroses, elephants, lagomorphs, rodents
Describe foregut fermentation
- digastric digestive system
- typified by artiodactyls
- cervids, bovids, kangaroos, colobus monkeys
Herbivorous specialisations
- granivory
- folivory
- frugivory
- nectarivory
- gummivory
- mycophagy
Describe the tube-lipped nectar bat
- protrusible tongue
- glossal tube
- tongue retractor
Give an example of nectivory
honey possums
List some gum-eating organisms
- marmosets
- bush-babies
- lorises
List some mycophagous herbivores
sciurids, cricetids, Potoridae
Describe gnawing mammals
- large gnawing incisors
- reaching and nibbling
Describe coprophagy (aka refection)
- digestion of cellulose in hindgut fermenters occurs in the cecum
- rapid digestion: minimal fibre
- shrews, rodents and lagomorphs
- large quantities of vegetation
- large caecum contains bacterial flora to digest cellulose
- dual passage of food
Describe coprophagous generalised morphology
- oesophagus
- stomach
- mixing zone
- alimentary mass
- fermentation in caecum
- excretion of hard faeces
- ingestion of caecal pellets from anus
Describe omnivore
- opportunistic
- opossums, primates, pigs,
bears and raccoons - versatile dentition (bunodont cheekteeth)
- relatively simple digestive system
Describe optimal foraging in ruminants
- need for sufficient energy
- need for sufficient sodium intake (aquatic plants bulkier; more sodium)
- size of the rumen
- triangulate constants
Describe extant whale skull telescoping
- terrestrial mammal (horse)
- archaeocete whale (heterodont)
- modern odontocete (common dolphin)
- modern mysticete (fin whale)
- extended posteriorly to overlap parietal bones
- nostrils have moved
components of skull (whale)
- nasal
- pre-maxilla
- maxilla
- frontal
- parietal
- occipital
Marine mammal feeding specialisations
- ## size of baleen
Describe whale feeding
- zooplankton
- arrangement of baleen in
upper jaw of mysticetes - size and number of plates vary among species
Describe whale feeding morphology
- upper jaw
- gum base
- baleen plates
- bone of lower jaw
- fringes forming filter mat
- tongue
- keel of palate
Describe the dentition patterns of pinnipeds
- most: generalist feeders
- modified cusps in filter- feeding crabeater seals, forming a sieve to filter krill
Describe generalist pinnipeds
well-developed cheekteeth, usually single-cusp and peg-like
List some pinnipeds
- Southern sea lion
- Northern fur seal
- Southern elephant seal
- Hawaiian monk seal
- Crabeater seal
- Leopard seal
