Chapter 26 - Non-Avian Reptiles and Mesozoic Diversity

A comprehensive review of non-avian reptiles and the Mesozoic diversity, focusing on key characteristics, adaptations, and evolutionary history.

Amniotes are defined by a set of extra-embryonic membranes that support the __.

developing embryo.

The origin of amniotes occurred during the __ transition, characterized by cooler and drier conditions.

Permian

The key innovations of amniotes include the __ egg, making water unnecessary for reproduction.

amniotic

In amniotes, lungs are ventilated by negative pressure via __.

ribs

The three skull types in amniotes are __, __, and __ skull types.

synapsid, diapsid, anapsid

Wastes must be detoxified in amniotes, primarily as __ acid.

uric

Anapsid skulls have __ conditions with openings, lacking both foramen and arches.

two

Diapsid skulls have __ openings and are characteristic of reptiles, birds, and dinosaurs.

two

Synapsid skulls are found in __ and their ancestors.

mammals

Crocodilians include species like __, __, and __.

crocodiles, alligators, caiman

The __ Order consists of about 300 species of turtles.

Testudines

Lepidosaurs predominantly include the group __, which encompasses snakes and monitors.

Squamata

Males of the Squamata group possess structures called __ for reproduction.

hemipenes

Jacobson's organ helps snakes to or their environment.

smell, taste

Tuataras are distinguished by their __ eye and have an unmodified diapsid skull.

pineal

Amniota Synapsida includes species such as and .

Dimetridon, humans

Archosaurs are noted for having an opening anterior to the __ shaped like an inverted triangle.

eye

The evolutionary trend in dinosaurs includes a movement towards __ posture.

bipedal

The two major groups of dinosaurs are and .

Saurischia, Ornithischia

The presence of antiorbital and mandibular fenestra is a synapomorphy of the clade __.

Archosauria

Pterosauria, derived from basal archosaurs, had adaptations specialized for __.

flight

Among dinosaurs, Saurischia includes the subgroups and .

Theropoda, Sauropoda

Characterizing the Sauropodomorpha, they typically have __ necks and small heads.

long

Theropoda are primarily __, having features such as sharp claws and serrated teeth.

carnivorous

The Saurischian dinosaurs had a variation in diets, with some evolving into __ and herbivores.

omnivores

Birds are derived from __ dinosaurs, specifically from the clade Theropoda.

theropod

The __ sternum is a notable adaptation in birds for flight.

keeled

The evolution of feathers in birds indicates specialization for __ and other adaptations for flight.

aerial locomotion

In the fossil record, __ represents a transitional species with features of both birds and reptiles.

Archaeopteryx

Plesiosaurs are recognized as aquatic carnivores that had a short, wide trunk and __ features.

specific tooth and skull

The adaptations of endothermic birds include __ for weight reduction during flight.

feathers

The skeletal structure of birds has evolved to form a __ backbone that helps in flight stability.

rigid

The term 'niche' in the context of dinosaur ecology refers to their role as terrestrial apex and large .

predators, herbivores

Amniotes' evolutionary innovations allowed the shift from __ to terrestrial environments due to their reproductive adaptations.

aquatic

Lepidosaurs exhibit the characteristic of shedding skin in __, enhancing their flexibility and growth.

one piece

The diet of herbivorous dinosaurs often required specialization in __ and other plant sources.

different plants

Archaeopteryx is a significant fossil as it exhibits features of __ and is a pivotal figure in avian evolution.

birds and reptiles.

Marine predation as seen in ichthyosaurs and plesiosaurs indicates adaptation to __ environments during the Mesozoic.

aquatic

Nesting behavior among __ dinosaurs highlights their social habits and parental care in some species.

ornithischian

Weight adaptation in birds is critical to achieving __ and efficient flight.

aerodynamics

The presence of __ played a vital role in the evolution of both reptiles and the eventual emergence of birds.

feathers

“Ring finger” wings in pterosaurs highlight __ adaptations related to flight.

bone structure