Diversity of Life Part Two

Question 1

What did mammals also evolved from in the Mesozoic?

Answer 1

From advanced types of synapsids that survived into the Mesozoic (first appeared in the Upper Triassic).

Question 2

What is one of the key evolutionary transitions in the evolution of the mammals from earlier synapsids?

Answer 2

The reduction in the number of bones in the lower jaw and their migration into the inner ear.

Question 3

What are early mammals mostly classified on?

Answer 3

Teeth (since that is all that usually found) - usually small (house cat sized). Teeth are harder than bone so they keep better; cheek teeth are very specialized in mammals.

Question 4

What are Monotremes?

Answer 4

Primitive egg laying mammals.

Question 5

How many living monotremes are there?

Answer 5

3, Platypus and two species of echidna. Found in Australia and New Guinea.

Question 6

What are the dominate mammals today?

Answer 6

Placental mammals.

Question 7

True or False: Comparatively, the young of Placental Mammals are born at a higher degree of development.

Answer 7

True.

Question 8

What is the oldest placental Mammal?

Answer 8

Eomeria from the Early Cretaceous of China.

Question 9

Where is the oldest marsupial found?

Answer 9

In the same rocks as the oldest placental.

Question 10

How old is the Sinodelphys?

Answer 10

125 million years old.

Question 11

How developed are Marsupial offspring?

Answer 11

Marsupial offspring are underdeveloped and spend time in their mothers womb.

Question 12

When did Diapsids evolve?

Answer 12

In the Carboniferous, but did not diversify until after the Permian extinction.

Question 13

What do Diapsids include?

Answer 13

Birds, reptiles, dinosaurs, and other Mesozoic reptiles. They have 2 openings on the side of their skull.

Question 14

What are examples of Marsupials?

Answer 14

Possums, kangaroos.

Question 15

What were Diapsids like in the Palaeozoic?

Answer 15

Small and lizard-like. Minor part of the fauna at this time, some moved into the oceans to become the earliest marine reptiles.

Question 16

What are Basal Archosaurs?

Answer 16

A group of diapsids that increased in numbers during the Mesozoic. Includes dinosaurs, birds, crocodilians, and pterosaurs. Most early ones were small, bipedal, lightly built animals.

Question 17

When did Basal Archosaurs first appear?

Answer 17

In the Triassic (lizard looking). The group is united by an opening in front of the eyes on the snout.

Question 18

What are characteristics of Basal Archosaurs?

Answer 18

Some reverted to being 4 footed, large aquatic and terrestrial carnivores. Convergently similar to crocodiles; were the largest land animals of the Triassic (up to 11m).

Question 19

When did Dinosaurs appear?

Answer 19

In the Upper Triassic.

Question 20

What were the two main groups of Dinosaurs?

Answer 20

Ornithischians and Saurischians, divided based on type of hips.

Question 21

What hips do Ornithischians have?

Answer 21

Bird-hipped.

Question 22

What hips do Saurischians have?

Answer 22

Lizard-hipped (birds, TRex).

Question 23

What is the oldest known bird?

Answer 23

The Jurassic Archaeopteryx from Germany. The ‘missing link’ found in 1860, found in Solnhofen of Bavaria. Clearly shows a mixture of dinosaur and modern bird traits.

Question 24

What are Pterosaurs?

Answer 24

Flying archosaurs that evolved in the Late Triassic. (Three different wings).

Question 25

What were the earlier group of Pterosaurs called?

Answer 25

Earlier groups called rhamphorhynchoids, which had long tails.

Question 26

What are the Pterodactyloids?

Answer 26

The tail-less pterosaurs. This group includes the largest animal to ever fly (Quetzalcoatlus wingspan = 12 m). Like birds, bones are hollow. This negatively affects the fossil record.

Question 27

What are Crocodilians evolved from?

Answer 27

Ancestors in the Late Triassic that were lightly built and most likely bipedal.

Question 28

When did the first true crocodiles appear?

Answer 28

In the Early Jurassic.

Question 29

When do crocodilians start looking like modern crocodiles?

Answer 29

In the Jurassic. Some reached huge sizes (12m and 8 tonnes).

Question 30

Why did a number of different reptile groups return to the ocean during the Mesozoic?

Answer 30

To exploit the rich food sources that were not being exploited by other animals.

Question 31

What are Plesiosaurs?

Answer 31

Marine reptiles that were paddle swimmers, some had long flexible necks and others had short necks and massive skulls. Breathe air (have to come up every hour). Found during Jurassic-Cretaceous.

Question 32

What are Ichthyosaurs?

Answer 32

Most fully marine of the reptiles; in many ways, dolphins are convergent with them. Very stream-lined body evolved for swimming quickly after prey; fins, lost back limbs. The tail fins are vertical and the tail moves horizontally. Give live birth, have young in water.

Question 33

What are Mosasaurs?

Answer 33

Large marine reptiles that seem to be ancestral to snakes and lizards. Have long tails, last of the marine reptiles (went extinct end of the Cretaceous). Probably gave live birth.

Question 34

What did land plants probably evolve from?

Answer 34

Fresh water green algae. The earliest spores of possible land plants appear in the Ordovician (well before the earliest body [plants] fossils appear in the Silurian).

Question 35

What were the first land plants?

Answer 35

Nonvascular (no specialized system for transporting water and nutrients throughout the body); not easily preserved in the fossil record.

Question 36

What were the earliest land plant fossils?

Answer 36

Liverworts from the Lower Devonian of Belgium.

Question 37

What group do the early vascular plants belong to?

Answer 37

The Rhyniophytes.

Question 38

What are Rhyniophytes?

Answer 38

The early vascular plants that were slender and leafless - had no roots. Best known of these is the Cooksonia.

Question 39

When did advanced spore-bearing plants appear?

Answer 39

With true leaves in roots, evolved in the Devonian.

Question 40

What were the first spore-bearing plants?

Answer 40

Lycopods (club mosses), sphenophytes (horsetails), pteridophytes (ferns), and Progynosperms (precursors to the seed-bearing gymnosperms). Some plants developed woody tissues at this time, enabling them to attain the stature of trees. Dominated huge forests in the Carboniferous with trees up to 40 m tall.

Question 41

What are Lycopods?

Answer 41

Club Mosses that formed a major part of the Devonian flora. 2 main groups; one extinct, that formed tall trees that dominated Carboniferous coal swamps. The second group remained small, like living members of the group. Sporangia at leaf-branch intersection and clustered in cones.

Question 42

What are Sphenophytes?

Answer 42

Horsetails; have a jointed hollow stem and distinctive spiked leaved fused in whorls. The sporangia are in cones, and some grew to heights of 20 m.

Question 43

What are Pteridophytes?

Answer 43

Ferns known from the Carboniferous, most common living spore-bearing plant. Sporangia found on bottom of fronds (composite leaves), some have tree-like stems.

Question 44

What are the Progymnosperms?

Answer 44

Forerunners of gymnosperms - superficially similar to tree ferns, but have woody trucks with structures similar to gymnosperms. Known from Devonian and Lower Carboniferous.

Question 45

What are Gymnosperms?

Answer 45

The first seed-bearing plants with exposed seeds. The gymnosperms evolved in Devonian and proliferated through the Upper Palaeozoic, and reached their peak in the Mesozoic.

Question 46

What are Angiosperms?

Answer 46

Seed-bearing plants that have flowers and seeds in fruit.

Question 47

When were the first gymnosperms in the fossil record?

Answer 47

In the Carboniferous and Permian. Looked like ferns but true seed bearing plants that evolved from progymnosperms.

Question 48

What is the origin of conifers?

Answer 48

Uncertain - occupied mainly dry environments and were important in the Carboniferous and Permian. Modern conifers appear in the Triassic.

Question 49

What are Cycads?

Answer 49

Plants that dominated the Mesozoic - dominated in the Jurassic when they formed large trees. They experienced a decline in the Late Cretaceous.

Question 50

When are the earliest Angiosperms from?

Answer 50

The Late Jurassic in China. By the Middle Cretaceous they were wide spread.