20 Class mammalia Flashcards
(35 cards)
(mamma =
breast
Name is derived from the possession of mammary glands which secrete milk for the nourishment of
their young
* Endothermic (warm-blooded) and homeothermic (able to maintain a stable internal body temperature)
* Tetrapod (but a few species can walk in 2 legs/bipedal)
* Found in all kinds of habitats (terrestrial and aquatic)
* Only 4300 species from 26 orders (1 order for monotremes, 7 orders of marsupials, 18 orders of
placental mammals)
Class mammalia
the skin, which consist of the epidermis + dermis
cutis
In places that are subject to much contact and use (ex. Palms, soles of feet), it is thick and cornified with
keratin
the layer below the epidermis that consist of dense connective tissue and cushions the body from stress and strain
dermis
small muscles attached to
hair follicles in mammals. Causes hairs to stand
on end to make animal look bigger.
Arrector Pili Muscle
(solid and thick strands) of
porcupines and hedgehogs,
Spines
(hard and rough strands) of hogs/pigs
bristles
in armadillos and pangolins
Scale-like plates
sensory hairs that provide a tactile sense; it is longer in nocturnal or weak-sighted animals because it provides a “sixth sense”
Vibrassae (“whiskers”)
hollow sheaths of keratinized epidermis that embrace a core of bone from the skull
horns
also keratinized, it is branched and composed of solid bone when mature
antlers
Occur over much of the body surface
sweat gland
secretes watery fluid that draws heat away from the skin and cools it;
* Occurs in hairless regions, but is all over in horses and primates
* Absent in rodents, rabbits, and whales
Eccrine glands
mammalian dentition has differentmorphology/appearance in order to perform specialized
Heterodont Teeth
has simple crowns and is mainly for snipping or biting.It is the front group of teeth.
incisors
has long conical crowns, specialized for
piercing. Usually 2 pairs (lower mandibular and
upper maxillary)c
canines
– have compressed crowns and suited for shearing, slicing, crushing, and
grinding
premolars and molars
mammals only have 2 sets of teeth
Diphyodont Dentition
(“milk teeth”) – the first and temporary set of teeth, which is replaced by a
permanent set when the skull has grown large enough.
Deciduous teeth
(like rodents, rabbits, beavers)
Gnawers
(cattle, goats, sheep, deer, etc.)
ruminants
This is a protein material that makes up the outer layer of mammalian skin, hair, horns, and nails.
Keratin
This is a type of gland that secretes fluid that can help regulate body temperature by cooling the skin.
Eccrine