Archaeology - Evolution in Fossil Record

Question 1

How fossilization varies with species?

Answer 1

Soft bodied species fossilise less, humid forests decay faster.

Question 2

How do we infer fossil record is incomplete?

Answer 2

The fact we still make discoveries, the largest dinosaur was found in spain in 2006.

Question 3

Fossils being lost…

Answer 3

Degradation by erosion, subduction and metamorphosis.

Question 4

Anagenesis

Answer 4

This is the formation of species without branching of the evolutionary line of descenet.

Question 5

Cladogenesis

Answer 5

This is the divergence of taxa due to selection of an adaptation to different envrionmental pressures/niches.

Question 6

Two types of evolution in lineage?

Answer 6

Anagenesis
Cladogenesis

Question 7

Example of evident evolutionary change?

Answer 7

Foraminefera CaCO3 shells(Contusotruncana shelll shapes become increasingly cone shaped)

Question 8

How can higher taxa be measured over geological time periods?

Answer 8

Displaying of macroevolution

Question 9

What are displayed that indicate higher taxa macroevolution?

Answer 9

Homology and
mosaic evolution

Question 10

Inferring evolution from similar characteristics…

Answer 10

Humans and primates having tails and opposalbe toes.

Question 11

Example of inferring evolution.

Answer 11

Sphecomyrma cretaceuos ants from primitve species and wasp families.

Question 12

Groups taxons are split in?

Answer 12

Stem groups and crown groups

Question 13

Origins of tetrapods…

Answer 13

Sarcopterygii (osteolepiformes) these gave rise to Tetrapods, then Ichthyostega

Question 14

Sarcopterygii

Answer 14

Lobe-finned fishes found 408mya in early Devonian (lungfishes and coelacanths)

Question 15

Ichthyostega

Answer 15

These had more flexibile neck due to gill removal, the same tail fin and distinct skull and teeth.

Question 16

Similarities of Ichthyostega to Sarcopterygians

Answer 16

Brain case had joints between anterior and posterior sections

Question 17

Ichtyostega relationship to mammalian evolution…

Answer 17

Mosaics of sarcopterygian and tetrapod

Question 18

Example of an intermediate form of tetrapod?

Answer 18

Tiktaalik a morph of the two(flat mobile head, elongated snout and no gill cover bones)

Question 19

Tiktaalik fin morphology?

Answer 19

Homologous humerus, ulna, radius and wrist provided evidence that limb could be flexed at elbow and the wrist

Question 20

What dinosaur taxon do birds belong to?

Answer 20

Theropod dinosaurs(initially defined by their feathers)

Question 21

First feathered dinosaur?

Answer 21

Archaeopteryx

Question 22

Archaeopteryx

Answer 22

Feathers for flight, theropod derived leg structure, tail elognation and clawed fingers

Question 23

Examples of other theropods with feathers?

Answer 23

Oviraptorosaur both feathered tail and arms.

Question 24

Preadaptations

Answer 24

Adaptations serving a different purpose from the one they originally evolved.

Question 25

How are mammalls document in the fossil record?

Answer 25

Characterisitc skeletal features(particularly skull and haw)

Question 26

Differences of mammals to reptiels…

Answer 26

Dentary bone instead of multiple
Jaw articulation between dentary and squamosal, whilst tettra between articular and quadrate
Singular sound transmission in early amniotes, mammals have three ossicles

Question 27

What did synapsids emerge from?

Answer 27

Amniotes with characteristc temporal fenestra,

Question 28

Importance of temporal fenestra.

Answer 28

Allows space for enlarged jaw muscles.

Question 29

Therapsida

Answer 29

With permian synapsids had enlarged canine teeth with suggestion of seperation of breathing passage from the mouth cavity by a recessed plate

Question 30

Cynodonts

Answer 30

Therapsids from late permian to late triassic represent several steps towards mammals.

Question 31

What steps of cynodonts towards mammals?

Answer 31

Compressed rear skull, enlarged dentary, several cusps row of cheek teeth, smaller quadrate and looser

Question 32

What followed cynodonts?

Answer 32

Morganucodon

Question 33

Morganucodon

Answer 33

Typical mammalian teeth, weak articular/quadrate hinge, fully developed mammalian articulation between dentary/squamosal.

Question 34

Articular/Quadrate bones in jone articulation in morganucodo?

Answer 34

Sunk into ear and became ossicles.

Question 35

Hadrocodium

Answer 35

Complete dentary bone in lower jaw, with full speration of articular/quadrate (followed morganucodon)

Question 36

Closest relative of cetaceans?

Answer 36

Hippo, cetaceans thus in Artiodactyla(alongside camels, pigs and ruminants)

Question 37

Where is cetacean evolution documented most?

Answer 37

Pakistan from aquatic locomotion transition from 50mya to 35mya

Question 38

First known cetacean whale…

Answer 38

Pakicetus

Question 39

Steps of whale evolution…

Answer 39

Pakicetus
Amvulocetus(adapted for shallow coastal waters)
Protocetids
Dorudontine(complete adaptation to water)