Vertebrates - Birds

Question 1

Where is bird evolution traced?

Answer 1

Coelurosaurs being a late theropod lineage

Question 2

Theropods

Answer 2

These were late triassic-terrestial predators

Question 3

What are the distinct skeletal features of bird?

Answer 3

Highly modified forelimbs
Trunk in horizontal position
Bone fusion in hindlimbs and digitidgrade
Paedomorphic

Question 4

Digitidgrade

Answer 4

This means to walk on the toes and not touch the ground with their hells

Question 5

Paedomorphic

Answer 5

This is the prolonging of larval life or retention or larval characteristics in seuxally marine animals

Question 6

What is a good identifir of evolution with birds?

Answer 6

Tracing skeletal structures to before bird lineages

Question 7

Furcula

Answer 7

This is the wishbone formed by ventral fusion of the right and left clavicles and the median interclavicle

Question 8

What is an example of bone fusion?

Answer 8

Furcula

Question 9

How is Furcula an identifier of evolution?

Answer 9

It is widespread in theropods now used for flight

Question 10

Pneumatization

Answer 10

THis is the presence or development of air-filled cavities in the bone.

Question 11

Why is the wrist joint important in birds?

Answer 11

Allows the carpometacarpus to inward bend and rest on the ulna and radius when the wing is folded(human rist on 90 degree bend)

Question 12

Uncinate Processes

Answer 12

These are bony projections in the ribs extending upwards and backwards from each rib, important in respiration

Question 13

What bone morphologies are used to indicate bird evolution?

Answer 13

Pneumatization
Uncinate processes
Furcula

Question 14

What was the discovery of the feather?

Answer 14

Found as a single feather in 1860, Archaeopteryx found in Solnhofen limestone

Question 15

What are the features of Archaeopteryx?

Answer 15

Had reptilian forelimb claws, boned tail and teeth, whilst bird-like feathers and wings

Question 16

What was the origin of feathers?

Answer 16

Theropods before birds in protofeathers

Question 17

What were the first protofeathers?

Answer 17

1-5cm long structures with beta-keratin presence

Question 18

What were early feathers in Coelurosaurs used for?

Answer 18

Sexual selection in displays and sex identificaiton

Question 19

How is Coelurosaurs sexual seleciton evidenced?

Answer 19

Ornithomimus juveniles contain only filamentous feathers whilst adults have both filaments and pennaceous feathers

Question 20

How can colour be determined in fossils?

Answer 20

Scannine electron microscopy in melanosomes

Question 21

When is lift generation preadaptations first seen?

Answer 21

Dromaeosaurs by sideway wrist rotation for prey grabbing

Question 22

What was the early proavian environment like?

Answer 22

Highly competitive, having long legs for much running

Question 23

What are the two theories of bird evolution?

Answer 23

From The Trees Down
From The Ground Up

Question 24

What doe sthe From The Trees Down theory say?

Answer 24

Origins of flight dreives from evolution of fliding in arboreal species with tree gliding

Question 25

What does the from the ground up theory say?

Answer 25

Proavian ancestor cursorial strucuts used as leverage to run up inclines