mamaliformes Flashcards
what does narrow pelvis development after monotremes allow for?
imporves muscles attachment for locomotion - as independent from caudal vertebrae
also probable switch from eggs to live birth with narrow pelvis
What are two defining characters of mammals?
hair and lactate (milk production)
What is likely reason for hair development? modifications?
insulation to keep metabolism up.
modifications probably allowed for camooflauge, communication and sensation following initial development
What is purpose of lactation?
separates offspring rearing from food abundance as can now use stored fat
What is a feature of all monotremes?
electroreceptive beaks
longer tailed sperm
males are venomous (spurs on hind legs)
How did mammals change of locomotion?
muscles attachment no longer to spin but to enlarged pelvis (ilium)
What are the three types of foot planting?
Plantigrade
Digitigrade
Unguligrade
What is Plantigrade?
heel on ground
What is digitigrade?
only digits on ground (e,g, cat)
What is unguligrade?
only tips of digits on ground (e.g. cows, horse, deers)
What are perrisodactyla?
odd toed ungulates (Rhino, Horse, Tapir)
What are ateriodactyla?
even toed ungulates (Deer, Pigs, Hippos, Whales)
What is difference between a deer jaw and canine jaw?
deer lower jaw is more L shaped and hinge is higher, all teeth contact at same time in a grinding action (not slicing)
What are hypsodont?
high-crowned teeth
What are hypselodont?
front incisors of rodents (ever-growing)
What are differneces between herivore and canine skulls?
canines generally have a smaller lower jaw and sharper teeth (canines) that are not lined up directly underneath each other
