Pelycosaurs and Therapsids Overview

<p>Eutheria (Placentals) (D)</p> Signup and view all the answers

<p>Nutrition for young offspring (B)</p> Signup and view all the answers

<p>Versatile feeding mechanisms (C), Extended parental care (D)</p> Signup and view all the answers

<p>Claws, hooves, and nails (B)</p> Signup and view all the answers

<p>Metatheria (Marsupials) (C)</p> Signup and view all the answers

<p>Permanent structure throughout adulthood (D)</p> Signup and view all the answers

<p>Small intestine (A)</p> Signup and view all the answers

<p>It is a feature that is retained in modern mammals. (C)</p> Signup and view all the answers

<p>Teeth evolved to have more specialized functions (C)</p> Signup and view all the answers

<p>Acrodont dentition (A)</p> Signup and view all the answers

<p>Blunt teeth for crushing (A)</p> Signup and view all the answers

<p>Moist environments to support gas exchange (A)</p> Signup and view all the answers

<p>Permian (C)</p> Signup and view all the answers

<p>Developed jaw musculature (C)</p> Signup and view all the answers

<p>Chiropterans (B), Primates (D)</p> Signup and view all the answers

<p>Shift to a more upright limb posture (C)</p> Signup and view all the answers

<p>Water is actively pumped over the gills (A)</p> Signup and view all the answers

<p>Teeth (C)</p> Signup and view all the answers

<p>Ability to regulate body temperature (A)</p> Signup and view all the answers

<p>Geological dominance over other reptiles (C)</p> Signup and view all the answers

<p>Regional differentiation of vertebrae (B)</p> Signup and view all the answers

<p>Homodont (A)</p> Signup and view all the answers

<p>Moisten food for lubrication (A)</p> Signup and view all the answers

<p>Two-part structure with a gizzard (D)</p> Signup and view all the answers

<p>Ribs and intercostal muscles (C)</p> Signup and view all the answers

<p>Unidirectional flow (A)</p> Signup and view all the answers

<p>Crop (D)</p> Signup and view all the answers

<p>Conduct food to stomach (C)</p> Signup and view all the answers

<p>Venom production (A)</p> Signup and view all the answers

<p>Parabronchi (C)</p> Signup and view all the answers

<p>It permits progressive loading of oxygen into the blood. (C)</p> Signup and view all the answers

<p>Three (C)</p> Signup and view all the answers

<p>It allows for complete separation of pulmonary and systemic circulation. (D)</p> Signup and view all the answers

<p>Counter-Current System (D)</p> Signup and view all the answers

<p>Air flow is unidirectional through the lungs. (A)</p> Signup and view all the answers

<p>Gas concentrations are relatively constant throughout blood flow. (B)</p> Signup and view all the answers

<p>It allows the transfer of deoxygenated blood to the lungs while breathing air. (B)</p> Signup and view all the answers

<p>To facilitate blood flow from the right atrium to the left atrium. (B)</p> Signup and view all the answers

<p>Ductus arteriosus (A)</p> Signup and view all the answers

<p>To chemically break down food. (D)</p> Signup and view all the answers

<p>Small intestine (C)</p> Signup and view all the answers

<p>Pancreas (C)</p> Signup and view all the answers

<p>Grinding and mixing food. (A)</p> Signup and view all the answers

<p>To regulate the flow of food into the small intestine. (B)</p> Signup and view all the answers

<p>Proventriculus (A)</p> Signup and view all the answers

An evolutionary lineage from Pelycosaurs to Therapsids to Cynodonts and eventually to Mammals, showing adaptations over time.

Pelycosaurs had a single opening (fenestra) in their skull behind the eye socket, unlike some ancestors with two.

Cynodonts developed more complex jaw muscles (masseter and temporalis) for better chewing compared to earlier groups.

Cynodonts evolved nasal turbinates to regulate temperature and water loss, suggesting a more active lifestyle.

Mammals have mammary glands that secrete milk for nourishing their young.

Mammalian vertebrae show regional specialization, like cervical vertebrae adapted for movement and lack of ribs.

Mammals have several key characteristics, including milk secretion from mammary glands, extended parental care, large brains, hair, etc.

A group of Permian therapsids known for their large, heavily armored skulls, possibly used for head-butting.

Different regions of the vertebral column (thoracic, lumbar, sacral, caudal) have distinct characteristics, such as the presence or absence of ribs and articulation with the pelvic girdle.

Mammalian middle ear bones (malleus, incus, stapes) evolved from parts of the jaw in their ancestors, including the palatoquadrate and Meckel's cartilage.

Mammals evolved a jaw joint between the dentary (a single bone) and squamosal bones, different from their ancestors.

Mammals have teeth with specialized functions, categorized into incisors, canines, premolars, and molars, each with specific roles in their diet.

Mammals began diverging before the KT extinction, continuing to diversify after the dinosaurs' demise, leading to the modern diversity of mammals.

Mammals have specialized glands (Sebaceous, Sweat, Mammary, Scent) that perform diverse functions including hair care, thermoregulation and parental care, with some related to sexual selection and defense.

Mammals evolved claws, hooves, and nails from their epidermis, which enhance their ability to interact with their environment.

Mammals are classified into three main groups: Monotremes, Marsupials, and Placentals.

Explosive diversification of mammals after dinosaur extinction.

Factors that speed up evolution of new species into various niches.

Fishes use tidal ventilation (pumping water in and out) for respiration.

Some amphibians, especially larvae, have external gills for respiration.

Amphibians absorb oxygen through their skin, efficient gas exchange.

Receives, digests, absorbs, and gets rid of food.

Teeth attach to the outer jaw surface (like many fish).

Teeth attach to the inner side of the jaw (lizards, salamanders).

Teeth that are embedded in sockets within the jawbone, providing stronger attachment and allowing for more force during chewing.

Having different types of teeth with specialized shapes and functions, like incisors for biting, canines for tearing, premolars for crushing, and molars for grinding.

Salivary glands moisten food to aid in lubrication, making swallowing easier.

A modified part of the esophagus in birds that serves as a storage compartment for food before it is processed in the stomach.

The first part of the bird's stomach that secretes digestive enzymes to break down food.

The second part of the bird's stomach with a tough lining that grinds and mixes food with gastric secretions, often aided by small stones the bird consumes.

Mammalian lungs are ventilated by negative pressure created by the contraction of diaphragm muscles and rib cage, pulling air into the lungs.

In fetal mammals, blood is shunted away from developing lungs and directly into systemic circulation. This happens through two bypasses: the foramen ovale and the ductus arteriosus.

An opening in the fetal heart that allows blood to bypass the right ventricle and flow directly from the right atrium to the left atrium.

A blood vessel in the fetus that connects the pulmonary artery to the aorta, allowing most of the blood to bypass the lungs.

A muscular tube that connects the pharynx to the stomach, transporting food down.

A muscular organ that stores food temporarily, breaks it down with chemicals, and has little absorption.

The specialized four-chamber stomach of ruminant animals like cows, allowing for efficient digestion of plant matter.

The tiny, branching tubes within a bird's lungs where gas exchange happens. They're surrounded by capillaries, allowing oxygen to pass from the air to the blood.

Birds have a different type of breathing than mammals – they use a two-cycle process that involves posterior and anterior air sacs. The air sacs act like bellows, keeping air moving continuously through the lungs.

Birds have a unique breathing pattern. First, they inhale air which goes into the posterior sacs. The first exhalation pushes this air into the lungs. The second inhalation brings more air, pushing the air in the lungs into the anterior air sacs. Finally, the second exhalation pushes the air from the anterior sacs.

Different types of lungs have evolved in vertebrates, with different branching patterns. Alveolar lungs have many branches, while faveolar lungs have fewer. Birds have a unique breathing mechanism that is unidirectional, meaning air flows in one direction through the parabronchi.

Most fish have a single-circuit circulatory system. This means the blood only passes through the heart once before circulating to the rest of the body. The heart has two main chambers - an atrium and a ventricle - and sometimes additional chambers.

Reptiles have a three-chambered heart (two atria and one partially divided ventricle). This allows some mixing of oxygenated and deoxygenated blood. The ventricle's partial separation helps direct blood to the lungs when breathing air and bypass them when diving.

Both birds and mammals have a four-chambered heart (two atria and two ventricles). This completely separates pulmonary and systemic circulation, preventing mixing of oxygenated and deoxygenated blood.

In birds, blood flows through a network of capillaries in the lungs that are perpendicular to the flow of air (parabronchi). This allows for highly efficient gas exchange, with blood constantly encountering fresh oxygen-rich air.