Exam 3 Quizzes: Amphibians, Sauropsids, Turtles, and Archosaurs

Comprehensive review flashcards covering key concepts from Quizzes 8, 9, and 10 on amphibians, synapsids, sauropsids, lepidosaurs, turtles, and archosaurs.

Based on the sequence of character evolution in the turtle shell, which combination of features would you expect to find in a stem turtle fossil?

A plastron and expanded ribs, but no carapace

In bird respiration, what happens next to air located in the posterior air sac?

When the air sac is compressed by body muscles, the air is pushed into the lung.

Why would discovering a fossil turtle with a nearly complete carapace and very small, separate gastralia be confusing to a paleontologist?

Because other fossil and developmental evidence suggests that the plastron evolved first by expansion of the gastralia before the appearance of the carapace.

According to current evidence, how is the lack of temporal fenestrae in turtles best explained?

A burrowing origin, as akinetic skulls are typical of burrowing vertebrates.

What selective pressure is likely to have driven the elaboration of the faveolar lung into an elaborate unidirectional flow system?

Low atmospheric oxygen levels during the Triassic period

How did the secondary evolution of autostylic jaw suspension in tetrapods alter the function of splanchnocranium elements in snakes?

It left the hyomandibula with no jaw suspension function, placing it in position to transmit vibrations from the jaw to the inner ear (functioning as the columella for hearing), while the quadrate now assists with swallowing large food items.

Which vertebrate groups ventilate their lungs using opposing muscles (or groups of muscles) to shift their internal organs, thereby altering thoracic chamber volume?

Crocodilians and turtles

Which structure appears during the development of scales in both lepidosaurs and fish?

Dermal papilla

Which type of lung or respiratory ventilation has the least amount of mixing of oxygenated and deoxygenated respiratory fluid?

Unidirectional flow in gill respiration

Akinetic skulls in vertebrates are often an adaptation for which lifestyle?

Fossoriality (burrowing)

What general feature of amphibians makes them particularly sensitive to environmental disturbance and promotes the amphibian biodiversity crisis?

Their thin, permeable skin makes them more sensitive to environmental toxins and susceptible to infection by introduced fungi.

How can we be sure that mammals are classified as amniotes?

Because they produce four fetal membranes during development.

Which group of amphibians has a majority of species that are viviparous and matritrophic?

Gymnophiona

In what way is lung ventilation in lungfish and amphibians an extension of gill ventilation in fish?

It moves fluid by changing the volume of the mouth and pharynx.

How is lung ventilation in amniotes similar to lung ventilation in amphibians, but different from gill ventilation in fish?

In amniotes and amphibians, the air has tidal flow (in and out through the same opening), whereas in fish, water flows unidirectionally.