Vertebrate Zoology Exam 4

Examples of flying vertebrates:

Birds, Bats, Pterosaurs

What does the synacrum do?

provides strong structure for attaching legs

Birds have highly modified reptilian scales called -------

feathers

What are feathers?

highly modified reptilian scales, epidermal scales

\------- are the warmest vertebrates. What is their average body temperature?

Birds

40-41 Celcius

What is the function of air sacs in birds?

enhance unidirectional flow of air through the lung

What structure produces bird sounds?

syrinx

How many ovaries do birds have? Oviducts?

one ovary, one oviduct

What is the nitrogenous waste component of guano?

uric acid

Uric acid is a nitrogenous waste product produced by birds. It is a component of-------.

guano

In the traditional classification scheme, birds are part of Class ------.

*Aves*

There are about ------- species of birds

10,000

Birds have many ------- characteristics.

reptilian

Birds are hypothesized to be closely related to the -------dinosaurs. In particular to dinosaurs such as the --------.

Theropod

\
Velociraptor

Birds have many skeletal characteristics in common with ------- dinosaurs.

theropod

Based on cladistics, birds may actually represent a living ------- that is specialized for flight.

dinosaur

The earliest bird fossils are from the ------- Period of the ------- Era.

\
There are about 12 fossils of this early bird. In what country were these fossils found?

Jurassic Period of the Mesozoic Era

\
Germany

What is the earliest bird in the fossil record?

\
What does its name mean?

*Archaeopteryx*

\
“ancient wing”

*Archaeopteryx* had both bird-like and reptile-like characteristics. What were some of these characteristics?

* feathers
* reptile-like head: teeth and scales
* reptile-like tail: well-developed with vertebrae

It is believed that *Archaeopteryx* only flew for short distances. Why?

* appeared to be relatively heavy
* no keel

What are the three groups of flying vertebrates?

* Pterosaurs
* Birds
* Bats

What is the first bird in the fossil record?

\
When did it appear?

*Archaeopteryx*

\
Appeared about 150 MYA during the Jurassic Period

The skeletal structure of *Archaeopteryx* appears very similar to what dinosaur?

the Velociraptor

T/F: Some Theropods had feathers:

True. It is hypothesized that Velociraptors may have had feathers.

When do the first birds appear in the fossil record?

the Jurassic Period, middle of the Mesozoic Era, about 150 MYA

When did birds radiate?

Cenozoic Era

The Cenozoic Era is known as “The Age of -------”, but ------- also radiated during this time

The Age of Mammals

\
birds also radiated

The first *Archaeopteryx* fossil was found in what year?

1861

Birds radiated in the------- Period of the ------- Era, but when did bird radiation first start?

Tertiary Period, Cenozoic Era

\
started in the Cretaceous Period, end of the Mesozoic Era

Birds widely radiated during the Cenozoic Era after surviving the:

K/T Mass Extinction event

T/F: Birds radiated during the Jurassic Period:

False. Birds first appear during the Jurassic Period, but they radiate in the late Cretaceous/ early Tertiary

T/F: During the Tertiary Period, some birds challenged mammals for domination of the terrestrial environment.

True. There were very large predatory birds, such as the Terror Bird and *Gastornis,* that often fed on mammals.

What was *Gastornis*?

Large, carnivorous, flightless bird of the early Cenozoic Era:

* up to 7 feet in height
* fast runner with large legs
* short wings
* large head with a large hooked beak used for killing prey and tearing meat

\*Also called Diatryma

What was the Terror Bird?

*Titanis walleri*

Large, carnivorous, flightless bird that lived up until about 2 MYA:

* around 7 feet tall
* lived in North America from Central Florida to Texas (possibly Alabama)

*Gastornis* was historically called -------.

*Diatryma*

What was *Diatryma*?

Large, carnivorous, flightless bird of the early Cenozoic Era:

* up to 7 feet in height
* fast runner with large legs
* short wings
* large head with a large hooked beak used for killing prey and tearing meat

\*Also called *Gastornis*

Birds have a variety of unique characteristics that are adapted to -------

flight.

pneumatic

air-filled

Birds have ------- bones. What does this mean?

pneumatic. Air-filled cavities.

The skeletal system of birds is well-adapted for flight: It is extremely -----, but -----.

extremely light, but sturdy.

For flight adaptation, the larger bones of birds such as the ------- bones and ------- bones are pneumatic.

leg bones and wing bones

Many bird bones, including the skull, are fused into one piece. Why?

Fused for strength

About how much does the skeleton of a 20 pound pelican weigh?

23 ounces

The trunk portion of the bird skeleton forms a rigid ------- for attachment of wings and wing muscles.

“rigid airframe”

Describe the pneumatic bones of birds:

The bones are hollow, but have cross structure to add strength.

The lightweight bones of birds help to facilitate -------.

flight

The vertebrae of the ------- portion of birds are fused together.

trunk

In birds, the ribs are fused to the ------- and -------.

sternum and vertebrae

What is the name of the braces between bird ribs?

uncinate processes

T/F: All birds have a large keeled sternum.

False. The Ratites (Ostriches, Rheas, Cassowaries, Emus, etc.) are keel-less birds

The large, keeled sternum found in most birds facilitates the attachment of ------- muscles

flying/flight muscles

\
particularly those for down strokes

What are the Ratites?

Group of keel-less, flightless birds that rely on running:

* Ostriches, Rheas, Cassowaries, Emus, etc.

T/F: Ratites are believed to have evolved from flightless birds.

False. Ratites have lost the ability to fly, they evolved from birds that could fly.

Sacral, lumbar, and caudal vertebrae fuse to form what structure in birds?

the Synsacrum

What is the function of the synsacrum?

forms a solid platform for attachment of legs

A bird’s toes are adapted to its -------.

ecology

Most, but not all, birds usually have ------- toes, with ----- facing forward and ----- facing backward.

usually have 4

\
3 facing forward

\
1 facing backward

Describe the toes of the Roadrunner.

\

4 toes: 2 facing forward and 2 facing backward to facilitate running- allows for a steady, even surface

The toes and feet in many birds are specialized for ------- and/or -------.

perching and/or capturing prey

Describe the perching mechanism in birds.

As a bird bends its legs to settle on a branch, the tendons automatically tighten the toes to grip the branch.

The ------- and ------- are strong structures for wing and leg attachment.

* Rigid “airframe”
* Synsacrum

Typical perching birds, like Conures, have a ------- -like perching mechanism

lever-like

The legs and toes of Ratites are adapted for:

walking, running, and kicking

Bird feathers are homologous to -------.

\
How so?

homologous to reptilian scales:

\
they develop in a similar fashion and are epidermal in origin.

\------- appear to be highly modified reptilian scales.

Feathers

T/F: Although birds are not the only group that can fly, they are the only group to have ever had feathers.

False: Some dinosaurs appear to have had feathers which may have been used for insulation rather than flight.

Feathers are composed of what protein?

keratin

The feather vane is made up of ------- and small hooks called --------.

barbs and small hooks called barbules.

What are the functions of feathers?

1. Flight
2. Insulation
3. Buoyancy
4. Camouflage
5. Advertisement and display
6. Territoriality

How do feathers function in flight?

Contour feathers provide a streamlined profile of the body to enhance flight.

\
Flight feathers give shape to the wings and tail and provide lift.

How do feathers function in insulation?

“Down feathers” are soft feathers that are usually under the contour feathers. They are important for insulation because their loose structure traps air.

Down feathers trap -------.

air.

What type of feathers are abundant in young birds? What is the function of this type of feather?

Down feathers

\
important for insulation

What type of bird has more feathers than any other bird?

Why do they need so many?

How many do they have?

Penguins

they need insulation from a cold climate

they can have up to 70 feathers per square inch

How do feathers function in buoyancy?

they increase buoyancy by trapping air, allowing birds to float on water

\------- feathers provide “shape” to the bird’s body.

Contour

Flight feathers provide -------.

lift

How do feathers aid in camouflage?

coloration allows birds to avoid predators by blending into their habitat

How do feathers function in advertisement and display?

Mature males of many species are often brightly colored to attract females

What are filoplumes?

special ornate feathers found in some bird species to aid in mate attraction

T/F: Birds have scales.

True: Birds have scales on their feet and legs

What type of scales do birds have?

epidermal scales (homologous to reptilian scales)

T/F: Birds are ectotherms.

False: Birds are endotherms/homeotherms

T/F: Mammals are the warmest vertebrates.

False: Birds are the warmest vertebrates. The body temperature of birds is about 40-41 C, mammals range between 28 an 38 C.

Endothermy and flight require an increased amount of energy. Therefore, birds have very efficient ------- and ------- systems to furnish energy.

Circulatory and Respiratory

Birds have a ------- -chambered heart.

4

In birds, there is a separation of ------- and ------- circulation.

Why?

pulmonary and systemic

\
they have a four-chambered heart

What group has the most efficient and complicated respiratory system of all vertebrates?

the birds

What is the need for the high efficiency seen in the bird respiratory system?

the efficiency is needed to sustain the energy requirements of flight and homeothermy.

Describe the muscular diaphragm in birds.

Nonexistent. Birds do not have a diaphragm.

Birds are ------- pressure breathers.

negative

Movement of -----, ------, and ------ move air through the lungs of birds. Why these structures?

wings, ribs, and sternum

\
They lack a diaphragm

Birds have ------- in their thorax and abdomen that attach to the lungs

air sacs

Birds normally have about ------- air sacs.

8 or 9

Air sacs enhance the ------- flow of air through lungs.

unidirectional

Mammals ------- old air. Air sacs decrease this in birds.

“rebreathe”

Air sacs help to cool birds in warm weather. Birds don’t -------.

sweat

Birds do not sweat, they give off heat in their -------.

breath.

For diving birds, such as the Brown Pelican, air sacs can act as ------ ---------.

shock absorbers.

Birds use both ------- and -------- cues.

sound and visual