Birds and Mammals PDF

What is the subclass and superorder of class Aves

Diapsida, archosaura

Birds are most closely related to _____ dinosaurs

Theropod

Flightless birds with no keel are called ______ birds

Ratite

Foot similarities between theropods and birds?

Bipedalism, tridactyl foot, digitigrade (walking on toes), intertarsal ankle, pointed claws

Bone similarities between theropods and birds (non-foot)?

Mobile S shaped neck, fused boney sternum, furcula (fused clavicle), pneumatic bones, acetabulum, horny bill

What evolutionary demand necessitated endothermy?

Demand for continuous locomotion

Birds maintain a _____ and _____ body temperature (Tb).

Increased and constant

The body temperature of birds demands high amounts of ____ and ____

Food and oxygen

_____ help retain heat and energy in birds

Feathers

What separated the link between locomotion and respiration?

Bipedalism

What are the three pre-adaptations for flight?

Feathers, bipedalism, efficient respiration

The arboreal theory of flight states that birds _______________

Climbed up trees and glided

The cursorial theory of flight states that birds ______________

Jumped off ridges and small heights

The wing-assisted-incline-running theory of flight states that birds ______________

Used wings to climb steep surfaces

After Archeopteryx, avian evolution focused on the ______ and shifted the center of mass towards the _________

Flight apparatus, thoracic region

Skeletal adaptations include ______ for better flight and ______ for perching

keeled sternum and hallux

The pelvic bones fused with sacral vertebrae, resulting in the _____ and _____

Synsacrum, pygostyle

The _____ processes in birds ensure ribs only move up and down.

Uncinate

Two reasons birds reverted to flightlessness:

High energy demand of flight, lack of predators

The worldwide colonization of birds gave rise to ______ spp.

16,000

What is the subclass of class Mammalia?

Synapsida

Mammals dominated ________ (before or after) the age of the Dinosaurs

Before

What are the 2 major non - mammalian synapsid (Single temporal opening) lineages?

Pelycosaurs and therapsids

Pelycosaurs are ____ (more or less) primitive, found in the ______

More primitive, northern hemisphere

Therapsids are ____ (more, less) primitive, found ______

Less, found extensively

The sail - backed synapsid is known as the:

Pelycosaur

Pelycosaurs have few _______ or ______ advancements over reptiles

Locomotion or metabolic

Two adaptations of pelycosaurs:

Specialized dentition, arched palate

Therapsids evolved from ________ lineage with the last survivors called the ______

Pelycosaurs, cynodonts

What is the major respiratory adaptation of therapsids

Limbs placed below the body

What are the signs that therapsids evolved higher metabolism?

Wide distribution, increased complexity of jaw muscles, heterodont dentition, secondary palate, development of diaphragm

Therapsids evolved _______ which gave them better temperature and moisture regulation

Turbinates

There _____ (is, is not) direct evidence of insulative hair in therapsids

Is not

Early true mammals were similar to _______ and were _______

shrews, carnivores

2 traits that characterize all extant mammals:

Hair, mammary glands

What is viviparity in mammals?

Nourishment of young inside womb

Mammary glands are derived _____ glands, and gave rise to _____ behaviour

Apocrine, suckling

All forms of milk contain:

Water, antibacterial properties, nutrients, pheromones

Early mammals had a small body size and low _______ until the ______ era

diversity, cenozoic

What factors increased mammal diversity?

Extinction of dinosaurs, decreased competition, decreased predation, climate change, continental movement away from equator

The radiation of mammals reflects _____ changes during the cenozoic

Vegetational

Diversification included:

Large grazers, extensive rodents, carnivores that preyed on mammals

In mammals, derived traits develop mainly through specializations in the _______

Dentition

Changes in dentition allow for fast radiation and speciation, such as ____ and _____

Generalists and specialists

What are the three groups mammals evolved into?

Monotremes, marsupials, eutherians.

What are the benefits of ectothermy?

Smaller body size possible, increased shape variation, higher

What are the costs of endothermy?

90% of energy cost is maintaining high Tb, 10% goes to biomass conversion (Smaller mammals especially)

Endothermy benefits?

Stable Tb, faster response times for brain and muscle tissue, constant activity levels, activity in cold, new food resources, higher reproductive success