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Vertebrate Zoology LU > Exam 3 > Flashcards

Exam 3 Flashcards

Origin of Chondrichthyes, Origin of Osteichthyes Part 1 and 2, Origin of Tetrapods Part 1 and 2, The Mesozoic, Origin of Amniota, and Living on Land (64 cards)

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1
Q

Where are Chondrichthyes placed phylogenetically?

A

Chondrichthyes occur within Acanthodii. Acanthodii is used primarily for extinct forms, as all extant forms are found within Chondrichthyes.

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2
Q

What are the extant members of Euchondrocephali and Elasmobranchii called?

A

Chimaeriformes refers to extant Euchondrocephalia, and Nesoselachii refers to Elasmobranchii.

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3
Q

What group refers to modern sharks within Neoselachii?

A

Selachii

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4
Q

What is a key feature of Chondrichthyes’ skin?

A

Placoid scales or tooth-like scales that make their skin rough and abrasive.

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5
Q

What is a defining characteristic of the Chondrichthyans skeleton?

A

Made of cartilage, which may display surface mineralization.

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6
Q

How are Chondrichthyans teeth arranged?

A

Teeth are arranged in whrorls, which may be a synapomorphy of all Eugnathostomes.

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7
Q

What type of reproduction is characteristic of Chondrichthyes?

A

Internal fertilization using a pelvic clasper as an intromittent organ.

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8
Q

How many extant species are there in Chimaeriformes?

A

56 species in 3 families

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9
Q

What is the reproductive mode of extant Chimaeriformes?

A

They are oviparous, laying eggs outside of the body.

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10
Q

What are common names for members of Chimaeriformes?

A

Chimaeras, ratfish, and ghost sharks

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11
Q

What are two sister clades within Neoselachii?

A

Selachii (Modern Sharks) and Batomorphi (Sawfishes, Skates, and Rays)

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12
Q

How does the mouth placement differ between basal Neoselachii and extant species?

A

Basal forms had terminal mouth placement, while Neoselachians have their mouths recessed under a protruding rostrum.

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13
Q

How do Batomorphs differ from Selachians in terms of pectoral fin attachment?

A

Batomorphi show fusion of the pectoral fins to the head, while Selachians do not.

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14
Q

What are the two main clades within Selachii?

A

Galeomorphi (includes famous sharks like white sharks and hammerhead) and Squalomorphi (which tend to be smaller and morphologically diverse).

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15
Q

What types of reproductive models are seen in Neoselachains?

A

Oviparity, viviparity, lecithotrophy, and matrotrophy.

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16
Q

Where are the fins on Batomorphs?

A

Fused pectoral fins and a ventral mouth.

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17
Q

What clade is Osteichthyes the sister group to?

A

Acanthodii

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18
Q

WHat are the two main sub-clades of Osteichthyes?

A

Sarcopterygii (lobbed-finned fish) and Actinopterygii (ray-finned fish)

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19
Q

Where is the diversity of Actinopterygii concentrated?

A

In Teleostei.

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20
Q

What accounts for less than 1% of Actinopterygii?

A

Basal Actinopterygian groups.

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21
Q

What happens to the lungs in less basal clades of Osteichthyes?

A

They become a gas bladder in Teleostei.

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22
Q

Name notable bones in the skill of Osteichthyes.

A

Dentary, opercle, maxilla, and premaxilla.

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23
Q

What composes the fin rays of Ostechthyes?

A

Lepidotrichia (segments)

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24
Q

What changed occured to the fins of Sarcopterygians?

A

The monobasic fin anatomy replaced the ancestral tribasic fin anatomy.

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25
What fin type do gars and blowfish display?
Abbreviated heterocercal caudal fin.
26
What is the significance of reduced basal fin elements in Holostei?
They share this feature with Teleostei.
27
What is the shape of the Teleostei caudal fin?
Homocercal
28
Why are Teleost scales thinner than non-Teleosts?
To allow more flexibility during swimming.
29
What special jaw feature do Teleosts have?
Mobile jaw elements with a flared oral cavity and a maxilla that rotates down and forward.
30
What role does the gas bladder play in Teleosts?
It provides buoyancy, reducing the need for fin use in maintaining position.
31
How do Teleost fins evolve?
Fins become more specialized for maneuvering.
32
What are some key features of Teleostei?
- Homocercal caudal fin for enhanced swimming efficiency. - Thinner scales allow more flexible body movement. - Mobile jaw elements allow for a wider oral cavity - Specialized gas bladder provides buoyancy, allowing fins to be used for maneuvering - Pharyngeal jaws complement the oral jaws, aiding in food processing Pelagic eggs are common, smaller, and buoyant, joining the plankton community as they develop
33
Key Features of Osteichthyes
- Lungs evolved into gas bladders in more derived clades like Teleostei - Skull contains multiple notable bones: dentary, opercle, maxilla and premaxilla - Fin rays are made of Lepidotrichia - Scales are covered in various forms of ancestral enamal - Fins shifted from a tribasic anatomy to monobasic in Sarcopterygians, while Teleosts reduced basal fin elements
34
What are the three geologic periods of the Mesozoic era?
Triassic, Jurassic, and Cretaceous
35
How long did the Mesozoic era last?
Almost 200 million years.
36
What was the position of landmases at the start of the Triassic period?
Pangaea was fully formed, spanning from the north pole to the south pole.
37
What land masses formed during the Jurassic period after Pangaea fragmented?
Gondwana and Laurasia
38
During what period did modern continents begin moving toward their current postions?
During the Cretaceous period.
39
Where was India located during thee Cretaceous period?
It was an island off the east coast of Africa.
40
What caused the high global temperatures during the first half of the Mesozoic era?
Rising levels of atmospheric carbon dioxide.
41
Was there any glaciation during the Mesozioc era?
No, there were no glaciers or icecaps, and forest occured in polar regions.
42
What happened to sea levels during the Cretaceous period?
There was a significant sea level rise, with epicontinental seas extending into the interiors of some continents.
43
Which group of amniotes was more diverse early in the Mesozoic era?
Synapsids were more diverse than Sauropsids early in this era.
44
What happened to dinosaur diversity during the Jurassic period?
Dinosaurs became larger and more diverse
45
When did dinosaur diversity peak?
During the Cretaceous period.
46
What radiated in the water during the Mesozoic era?
Teleostei fishes and some tetrapods returned to water
47
What evolutionary event occured between marine predators and their intervertebrate prey?
The Mesozoic Marine Revolution, an evolutionary arms race between predators with crushing jaws, and armored prey.
48
What caused the End-Triassic period mass extinction?
Likely caused by intense volcanism and climate change due to the breakup of Pangaea.
49
How many clades of terrestrial and aquatic tetrapods were lost in the End-Triassic mass extinction?
18 Clades
50
What caused the End_Cretaceous (K-Pg) mass extinction?
The Chicxulub meteor strike and intense volcanism.
51
What percentage of tetrapod families went extinct during the K-Pg extinction?
43% of Tetrapod families.
52
Landmass Positions
- The Triassic period began with Pangaea fully formed, spanning from pole to pole. - In the Jurassic period, Pangaea broke into Gondwana and Laurasia, separated by the Tethys Sea. - By the Cretaceous period, the modern continents began to move toward their current positions.
53
Mesozoic Extinction Events
- End-Triassic Extinction: Linked to volcanism and climate change caused by the breakup of Pangaea, 18 Clades of terrestrial and aquatic tetrapods were lost. - End-Cretaceous (K-Pg) Extinction: Caused by Chicxulub meteor strike and intense volcanism. 43% of Tetrapod families went extinct, affecting Archosaur and Mammalian clades.
54
Osteichthyes
Bony Fishes
55
Mammals
Synapsid
56
57
Lepidosauromorpha
Tuatara and Lizards (including snakes)
58
Teleostei
Eels, Catfish, Tarpon, Tuna, Trout, Cod
59
Elopomorpha
Eels
60
Osteoglossomorpha
Bony-tongue fish
61
Siluriformes
Catfish (apart of Teleostei)
62
Zeiformes
Dories
63
Selachii
Modern Sharks like white sharks and hammerheads
64
Batomorphi
Skates and Rays

Vertebrate Zoology LU (1 decks)

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