EUTHERIAN MAMMALS
Eutherian Mammals are classified into
orders on the basis of dentition.
It does not involve phylogeny.
Dinosaurs..?
TROPHIC TYPES FOUND AMONG
EUTHERIAN MAMMALS
• Predators
– Flesh eaters
– Insectivores
– Scavengers
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Grazers
Frugivores
Nectar drinkers
Strainers - Plankton
Radiation of mammalian feeding habits
Early Insectivores
GENERALIZED MAMMALIAN DENTITION
TEETH
•Much of the adaptive success of mammals is related to
teeth
•Mammals are the only vertebrates that masticate food
•Mammalian teeth are adapted for various diets
• There is a relationship between dentition and feeding pattern.
• It impacts shape and structure of jaw and associated
musculature
• [temporal, masseter, and pterygoid muscles]
•Mammalian fossil record is typically teeth (and isolated jaws)
Cusp pattern of mammalian teeth
CARNIVORES
Cats
Cat branch
Civets
Hyenas
Dogs
Bears
Dog/bear branch
Red Panda
Seal
Sea lion
CARNIVORES
The fourth upper premolar and
first lower molar in the jaws of
many modern carnirora are
enlarged and bladelike.
Termed carnassial teeth,
they are used for slicing and
chopping.
Tiger Skull
Brachyodont & Bunodont teeth
Omnivores
Low-crowned teeth, is termed brachydont.
Human teeth are brachydont & bunodont.
Brachyodont teeth
OMNIVORES
Pigs, bears, monkeys, man
Bunodont dentition
Cusps are low and rounded.
The figure shows upper cheek teeth of a young domestic pig; some bunodont
dentition, such as human teeth, are simpler; others are more complex.
Hypsodonts
• Mammals that feed on rough substances are
subject to rapid wear on their teeth.
• Many of these species have especially highcrowned teeth, that is, teeth that extend
unusually far above the gumline, providing lots
of extra material for wear.
• These teeth are called hypsodont. The teeth of
cows and deer are hypsodont.
Lophodonts
• Herbivores must efficiently and thoroughly grind
their food, which is many cases is hard and
rough.
• The addition of hard enamel ridges to the teeth
improves their grinding action. These teeth are
called lophodont.
– Lophodont teeth have elongated ridges called lophs
that run between cusps.
– The molars and premolars of tapir, manatees, and
many rodents are lophodont.
– Extreme lophodonty is seen is modern elephants.
Lophodonts
HERBIVORES
Grazers
Horse
LOPHODONT & HYPSODONT
Perissodactyls have
lophodont (ridged)
teeth.
Special Dental Adaptations
Frugivore
an animal that
mainly eats fruit
• Fruit bat Pteropus, uses its sight and smell to find food. Fruit bats
are nocturnal.
• They drink fruit juices by crushing the fruit in the mouth and
pressing the tongue against the upper plate.
• Juice and soft pulp are swallowed, but the bat spits out the skin,
hard pulp, and seeds in the form of a pellet.
• The usual diet consists of bananas, guavas, mangoes, papayas,
flowers, nectar, pollen and sometimes leaves or bark.
NECTAR FEEDERS
Micro chiropterans
Nectar bats feed on the nectar and pollen.
Their long tongues enable them to reach
deep within the flowers to obtain the
nectar, much like hummingbirds.
Vampire bats are the only mammals that feed exclusively on blood. The
three species are all found in Central and South America. Two feed almost
entirely on bird blood, but the common vampire bat feeds on the blood of
mammals.
Homodonts
Dolphins & Toothed Whales
• They are predators, feeding actively on
fish and squid.
• They possess sharp teeth, usually in
both jaws, used to catch their prey.
Humpback whale
14 m
Baleen whales do not have teeth. They have baleen, which is made of
Keratin, the same material as our fingernails or hair. These teeth are
arranged like the teeth of a comb, The whales open their mouths to fill
it with water. Then they force the water out of their mouths, and the mat
on the inside of the baleen teeth catches plankton.
Gray whales are baleen whales. They feed in a number of ways, but
are specially suited for bottom-feeding. The whale dives to the ocean
floor, turns on its side, and sucks up a mouthful of sand and mud.
With its short baleen, it filters out and eats tiny crab-like animals
called amphipods, or worms that live in the muck.
Aardvark; Order Tubilidentata
anteaters have long noses, long sticky tongues, and strong
sharp claws, but they do not have any teeth.
Armadillo; Order Edentata
Pangolin; Order Pholidota
Skull of ant giant eater
Non trophic
functions of
teeth