Lecture 32 Amniotes - Reptiles

Question 1

what are the two major clades of amniotes?

Answer 1

• reptilia : includes birds

- synapsida: mammals and extinct taxa

Question 2

what are amniotes?

Answer 2

• group of tetrapods whose living members are the reptiles, including birds and mammals
• many adaptions for terrestrial life
• amniotes are tetrapods that have a terrestrially adapted egg

Question 3

what is the key unifying feature of amniotes

Answer 3

amniotic egg

Question 4

what are the four extraembryonic membranes that surround and protect the developing embryo

Answer 4

• allantois, chorion, amnion, yolk sac

- no need for water to reproduce – fully adapted to life on land

Question 5

what is the allantois?

Answer 5

waste disposal sac and gas exchange organ

Question 6

what is the chorion?

Answer 6

gas exchange of O2 and Co2 between embryo and air across shell

Question 7

what is the amnion?

Answer 7

protects embryo from mechanical shock

Question 8

what is the yolk sac

Answer 8

contains yolk stores nutrients

Question 9

what kind of eggs are there?

Answer 9

• porous calcareous or leathery shell impervious to water loss

Question 10

what kind of eggs are there?

Answer 10

• porous calcareous or leathery shell impervious to water loss

Question 11

if amniotes don’t lay their eggs on land what do they do with the eggs?

Answer 11

• retain the fertilized egg within the mother

Question 12

how do amniotes develop?

Answer 12

direct development

Question 13

what are other terrestrial adaptations in addition to the amniotic egg?

Answer 13

• thick, stratified, and relatively impermeable skin

- ability to use muscles associated with rib cage to ventilate lungs

Question 14

what are the classification of amniotes?

Answer 14

• anapsid: zero holes in post jaw area: turtles
• synapsid: one : turtles
• diapsid: two holes per side behind eye socket : reptilia

Question 15

what are the two major clades of amniotes?

Answer 15

• reptilia

- synapsida – mammals and numerous extinct taxa

Question 16

what does class reptilia include?

Answer 16

• tuataras, lizards, snakes, turtles, crocs, birds, dinos

Question 17

what are characteristics of non-avian reptilia?

Answer 17

• skin protected by thick, dry, keratinous scales that create a waterproof of barrier; skin shed in sections, as in turtles, or all at once
• leathery eggshell - protects from dessication, some are viviparous, with e

Question 18

what are characteristics of non-avian reptilia?

Answer 18

• skin protected by thick, dry, keratinous scales that create a waterproof of barrier; skin shed in sections, as in turtles, or all at once
• leathery eggshell - protects from dessication, some are viviparous, with extraparous
• most reptiles are ectothermic
• 3 chambered hearts
• little or parental care of young

Question 19

what are characteristics of non-avian reptilia?

Answer 19

• skin protected by thick, dry, keratinous scales that create a waterproof of barrier; skin shed in sections, as in turtles, or all at once
• leathery eggshell - protects from dessication, some are viviparous, with extraparous
• most reptiles are ectothermic
• 3 chambered hearts
• little or parental care of young

Question 20

what was the first major group of reptiles?

Answer 20

• parareptiles, which were mostly large, stocky quadrupedal herbivores
• as they were dwinding, diapsids were diversifying

Question 21

what are the main lineages of diapsids?

Answer 21

• lepidosaurs

- archosaurs

Question 22

what are the main lineages of diapsids?

Answer 22

• lepidosaurs

- archosaurs

Question 23

what are lepidosaurs?

Answer 23

tuataras, lizards, snakes, and extinct mososaurs

Question 24

what are archosaurs?

Answer 24

crocodilians, pterosaurs, and dinosaurs

Question 25

what are pterosaurs?

Answer 25

were first tetrapods to exhibit flight

Question 26

what did dinosaurs include?

Answer 26

• bipedal carnivores, theropods from which birds descended

Question 27

what are the major groups of extant non-avian reptiles?

Answer 27

-turtles, crocodilians, tuataras, lizards, snakes

Question 28

what is order testudines?

Answer 28

amniotes - reptiles - turtles

• have a boxlike bony or cartilaginous shell made of dorsal and ventral shield
• anapsids
• intromittent organ
• herbivores and carnivores

Question 29

what are lepidosaura: order tuataras?

Answer 29

• lizard-like

- look like lizards, but lack the modified jaw structure and male genitalia present in squamates

Question 30

what are lepidosaura: order tuataras?

Answer 30

• lizard-like
• look like lizards, but lack the modified jaw structure and male genitalia present in squamates
• teeth fused to jaw bones
• copulate but lack intromittant organ

Question 31

what are lepidosaura: order squamata?

Answer 31

• lizards and snakes
• characterized by: loosely jointed jaws and skull
• paired hemipenes in male
• external ear openings
• lizards: well developed limbs
• snakes: no external limbs

Question 32

what are archosaurs - order crocodilia?

Answer 32

• crocodilians (alligators and crocodiles)
• belong to an archosaur lineage that dates back to the late Triassic
• can’t chew
• extant species can walk on land
• males have a single intromittent organ
• exhibit maternal care

Question 33

what are extinct reptiles?

Answer 33

parareptiles and numerous diapsids

Question 34

what are parareptiles?

Answer 34

anapsid reptiles that may or may not have left any descendants

Question 35

what are the extinct aquatic diapsids?

Answer 35

• ichthysaurs - dolphin like, short necks, fish-like tails

- plesiosaurs - near lizards, flippered marine reptiles

Question 36

what are archosauria?

Answer 36

• extinct
• include pterosaurs and non-avian dinosaurs
• only extant members: crocodilians and birds
• represent one of 3 independent origns of flapping flight among vertebrates

Question 37

what are theropods?

Answer 37

bipedal saurischian dinos

• may have been the ancestors of birds
• many had feathers