Lecture 34: Aves and Mammals Flashcards
Shared common ancestor with birds?
Archaeopteryx
Class Aves?
Birds and crocs are extant group of archosaurs
Modern bird characteristics?
Amniotic egg
Scales on legs
Endothermic
Adaptations for flight
Hollow bones feathers reduced digits Horny beaks Gizzard
Precocial
Young feed themselves
Altricial
Born helpless and featherless
Bird ecology?
Terrestrial, freshwater, marine
preds, herb, scav, and omni
Amniote Phylogeny?
Reptilia (birds) and Synapsida (mammals)
Synapsids?
Hole in skull
non mammals extinct
Therapsids?
Enlargment of dentary bone on jaw
Bony secondary palate
Class mamalia characteristic?
movement of leftover jaw bone to middle ear
Mammary glands
Endothermic
Dentition different from reptiles
Monotreme clade?
platypus and echidnas Oviparous (lay eggs) Cloaca Lack teeth Feed on invertebrates
Mammals with placenta
Marsupials and eutherians
Marsupials?
Born as partially developed embryo
Crawl to mother’s pouch
Eutherians?
nourish young via placenta till well developed
then milk
no cloeca