Birds and Mammals

Question 1

What are the only descendants of the dinosaurs that lived during the mesozoic?

Answer 1

BIRDS, are dinosaurs that are no longer dinosaurs

Question 2

Similarities between modern birds

Answer 2

Have a beak with no teeth, wings, feathers for flight, and for insulation

Question 3

What did birds lose?

Answer 3

Teeth and heavy bones and muscles that support them are unnecessary weight to a flyer

Question 4

What is a pygostyle?

Answer 4

Formed from the fusion of the last several vertebrae of the bird’s spine

Attachment for tail feathers, tail feathers essential for flight are bound to the pygostyle with ligaments and muscle

Question 5

What is the sternum?

Answer 5

Location where ribs come together to connect at the chest, strong to protect our organs FOR HUMANS

FOR BIRDS usually reshaped into a long ridge of bone called the bird’s KEEL named after the keel of a ship

Question 6

DIURNAL animals

Answer 6

Day time

Active in the daylight and go to sleep at night when the sun goes down

These animals live their lives in the sunlight

Question 7

NOCTURNAL animals

Answer 7

Active in the nighttime and go to sleep during the daylight hours

Question 8

What was unique about mammals until the extinction?

Answer 8

MAMMALS WERE NOCTURNAL UNTIL THE EXTINCTION, extinction of dinosaurs let mammals come out of hiding and step into the sunlight

ALOT OF ANCESTRAL MAMMALS SPRUNG UP AFTER THE EXTINCTION

Question 9

What are the three modern animal mammals?

Answer 9

Monotremes, marsupial, and placentals

Question 10

What do most common mammals present?

Answer 10

Earth today all common mammals fall within the placental group

Question 11

What are monotremes?

Answer 11

Egg laying mammals that are the MOST ARCHAIC modern group of mammals

PLATYPUS and ECHIDNA

Reptilian sprawling gait

Lack of teeth

Question 12

What are marsupials?

Answer 12

Only mammals with pouches, carry the highly underdeveloped newborn marsupial young

Dont have placenta meaning that the children will be forced out quickly when they start to develop

Question 12

What are placentals?

Answer 12

Mammals with a placenta, placenta connects the developing embryo directly to the mother’s blood supply

Placenta organ responsible for gas exchange, nutrient uptake, and waste disposal

Placenta acts as a barrier between the immune systems of the mother and child, without placenta, the mother’s body will see the child as a foreign invader

Question 13

What mammal group was the most dominant?

Answer 13

DURING CENOZOIC marsupials were the dominant mammals of the southern hemisphere

INHABITED south america, antartica, and australia

Question 14

What is unique about monotremes?

Answer 14

Have teeth when young, these teeth are lost as adults but are very distinctive and are found in fossil monotremes

Question 15

What do marsupials also have?

Answer 15

Marsupials have EPIPUBIC BONES on the front of their pelvis that stick outward and upward

ALL have a pair of PALATAL HOLES within the palate (roof of mouth) of their skulls

^^^^^ ABSENT IN MONOTREMES AND PLACENTALS

Question 16

Common ancestor shared by all mammals

Answer 16

PROTUNGULATUM

Question 17

GROUP CARNIVORA

Answer 17

ALL cats, hyenas, dogs, bears, and handful of marine mammals

Nearly all members are exclusive carnivores

Question 18

Characteristic of carnivora

Answer 18

Have carnassial teeth for shredding and tearing meats

Thats why dogs are biting from the side of the mouth since they are using their carnassial teeth

ALL HAVE keratin claws, cats have a notch in their second finger bone to make space for their claws to retract

Cat claws remain very sharp because of this but dogs have blunt toes

Question 19

HOOVED ANIMALS

Answer 19

Ungulates

divided into groups based on the number of toes in their hoof

Question 20

EVEN TOED UNGULATES

Answer 20

ARTIODACTYLS

even number of toes

CAMEL , DEER, PIG, HIPPO

Question 21

Cetaceans, dolphins, and whales

Answer 21

ALL Cetaceans, dolphins and whales share a similar descent and have a similar body plan

all differences are superficial

Question 22

CETACEANS

Answer 22

ALL HAVE tail flukes, dorsal fin, flippers, and a blowhole atop their head

Unique to the cetaceans

Question 23

Swimming for whales and dolphins

Answer 23

Swim by flapping their tail flukes up and down rather than side to side

differ from fish and sharks who swim side to side tail flap

Question 24

WHALES

Answer 24

Were born of even toed hooves animals that were related to the ancestors of hippos, reduced their legs and adapted flippers

LEGS AND PELVIS NEARLY LOST

Blowhole of whales formed from the migration of the nostrils to the top of the head

Question 25

PERISSODACTYL

Answer 25

ODD TOED ungulates

odd toed ranging 1-5

HORSE, RHINO, HYRAX, ELEPHANT

Question 26

HORSES

Answer 26

TREND toward fewer toes through time since toes are fragile and easily broken, so the remaining toe is robust and strong like a leg (hoove)

Increase in body size from SMALL TO LARGE animals

Modern Horses largest horses ever

Question 27

ELEPHANTS

Answer 27

Evolved from odd toed ungulates

overtime experimented when it came to teeth, tusks, and trunk shape

Elongation of canine tusks

Lower jaw and smaller teeth, trunk grew larger over time

Question 28

EARLY ELEPHANTS

Answer 28

Was used like a large shovel for scooping food and water over time this lower jaw would be reduced

AS JAW GOT SMALLER, trunk grew in order to drink water

Question 29

MANATEES

Answer 29

Closely related to elephants

SHARE similar feet, nails, grey hairless skin and teeth

Both capable of manipulating food with their flexible lips and/ trunk