27.19 Vertebrate Diversity

The relationships among major clades are shown in this hypothesis.

Only gnathostomes have a jaw, but Derived characters are listed for some clades.

For example, the hagfishes and lampreys are vertebrates with highly reduced vertebrae, because derived traits have been lost over time or in reduced form.

They have defense-secreting glands.

Amphibians have a hole in the side of a fish.

The lamprey reptiles and mammals eat their host's blood and tissues.

The ray-finned fishes were rediscovered in the Indian Ocean in 1938 after being extinct for 75 million years.

Lungfishes can have both mammals and lungs.

A record of about 450 mil ion years ago is among the diverse ones.

More than 27,000 species of ray-finned swim efficiently after prey, and their jaws allow them to grab prey whole or bite off chunks groups combined, which is almost as many species as in other vertebrates.

The rod meter is one of the key characteristics of lobe-fins, and some giants have more than 10 m shaped bones surrounded by a thick layer of muscle.

The gnathostomes had fins years ago.
The chondrichthyans, ray-finned fishes, and jawed vertebrates are some of the fish species that lived in the brackish waters of the Devonian.

These organs were adapted to life on land and gave rise to limbs and digits.

Some of the events and consequences of bilaterian radiations I and II are discussed in this review.

The ocean's large eukaryotes were slow moving prior to these radiations.
A rich diversity of large, well-defended prey appeared as a result of the radiation of marine invertebrates that began during the early Cambrian.

The rise of aquatic vertebrates, which excelled at capturing food, made the ocean more dangerous.

The jaws of sharks, rays, and their relatives are adapted for feeding.

There are four characters derived from calcium.

There are about 1,000 species of living chon.

The majority of animals are in environments from 535 to 400 mil ion years ago.

Evolution is not goal oriented, for example, for ex sharks and their relatives.

For suggested answers, see Appendix A.

Fossils show arthropods were among the first animals to colonize land around 450 million years ago.

Some bilaterian animals colonized land and fragments of arthropod remains lead to profound changes there as well.

Early animal colonists had opportunities on land.

The atmosphere had more oxygen than early forests.

terres did aquatic environments, and there were new sources of food trial animal communities that were similar to those of today.
Detritivores, animals that eat decaying chal enges as wel, were included.

The re Such chal enges can be lethal.

The soft body of a semblance is so strong that it appears as if the land animals jel y, for example, provides no support against gravity; hence, a simply walked or crawled ashore, as in terrestrial snails and jel y cannot move or survive for long when stranded on land.

Despite the chal enges, members of many animal groups reproduce.

More extensive changes took place in other cases.
The place of arthropods is described shortly for the colonization of land by invaded land multiple times.

Three major groups of organisms that live on land are identified in this chart.

The red type indicates that the ancestors have evolved.

Most of the adaptations in plants evolved after the split.

Two large clades of animals--the insects and the vertebrates--show many ancestral characters that facilitate their transition to life on land.

The ones that happened in plants were 10:11 AM.

The coloniza tion of land was aided by the development of the aquatic relatives of animals that colonized the land.

One pair per arthropods.

The colonization of land by insects is what we focus on after describing the general features of the arthro tail segment).

The appendages of some arthro Walking legs have become modified over the course of evolution, specializing in functions such as walking, feeding, sensory reception, reproduction, and defense.

The lobster's body is covered in arthropods that have distinctive features.

If you've ever eaten an appendage, you know that the cuticle can be thick and hard over some and swimming appendages.
The head has a pair of parts of the body that are thin and flexible.
The whole body is covered.

The animal is protected by the rigid exoskeleton and the muscles that move it.

There ismoths land.

The arthropods left the water.

A variety of specialized gas exchange organs look like arthropods.

Most aquatic species have thin, feathery gils with extensions that place an extensive surface area in contact with which is specialized for dispersal of the surrounding water.
Terrestrial arthropods have both general and reproduction.

The bees and wasp are in the ducts.

They trate the body and carry oxygen to cells.

Fly insects fill the air and live in fresh water.

An animal that can fly can find food and mates in new habitats.

We show just ground because insects have more described than an animal that must crawl about on the species.
Three of the many insect clades have one or two pairs of wings.

The name of the group side of the thorax is "four feet" in Greek.

tetrapods have limbs with digits because of the toral and pelvic fins.
The legs are exten and the feet are sions of the cuticle, which allow the ground insects to fly.
The neck of a walking animal is different from the neck of a tsar.

Some of the species are clumsy on the ground because of the bones of the pel into wings.

As you read in the ground, you will be transferred to the rest of the body.

A fossil record of diverse insect mouth shows that specialized modes of feeding on fins lived in coastal wetlands.

Those that entered shal ow, gymnosperms and other Carboniferous plants could have used their lungs to breathe air.

Some species used their stout fins to swim and walk, and the evolution underwater across the bottom stimulated sect diversity.

The period was about 100 million years ago.
The insect and plant body plan did not evolve "out of nowhere" but was altered due to the mass extinction.

The discovery of a fossil cal ed Tiktaalik gave new details on how this process occurred.

The evolution of the limbs and feet of the tetrapods took place hundreds of years ago, when the fins of a lineage of lobe- fins began to evolve.
The basic fishlike anatomy of al vertebrates was the same until then.

eagles to humans

Paleontologists were looking for fossils that could shed light on the evolution of thepods.

Researchers were looking for a dig site with rocks that were about 400 million years old.

It was once a river.

Lungfishes branches have known fossils in time, while arrowheads show lineages that extend to today.

The colors in the drawings of extinct organisms are fanciful.

The fish had fins, gils, and lungs and was a member of the tetrapods.

Some of the species were covered in scales.
Tiktaalik had a ful set of gils and had weak limbs, but others had lost their gils and ribs that would have helped it breathe air and support its body.

Unlike a fish, Tiktaalik had a neck and shoulders and most of it moved its head about.

The bones of Tiktaalik's front were tied to water, a char fin had the same basic pattern found in al limbed animals.

The salamanders and Frogs were part of the same family.

Amphibians live first in water and then on land during lowed paleontologists to reconstruct how fins became progres larval stage and then on land as adults.

When a tadpole that lives in water transforms into a lung-breathing frog that lives, it's typical of such species.

Climate change, habitat loss, and the spread of a disease-causing chytrid fungus are some of the causes.

Declines have become extinctions in some cases.
According to recent studies, at least 9 amphibian species have become extinct in the last four decades, and more than 100 other species have not been observed in that time.

The tails of salamanders are retained C O N C E P T C H E C K 2 7.

Appendix A contains suggested answers.

Some salamanders are aquatic, but others live on land, as we'll see in Figure 27.27a.

We will begin by considering ter adults or throughout life.
salamanders that live on land restrial adaptations in amniotes have a side-to-side bending of the body, a trait also found in today's salamanders.

Frogs are better suited for moving on land than salamanders.

Amniotes are named after the character that hops along the terrain.

The animals known as "toads" are simply frog that have four special parts: the amnion, the chorion, the yolk sac, and the al antois leathery skin.

The amniotic egg was a key evolutionary step in Final y and the caecilians are legless.

Their lack of legs is a secondary adaptation, as they on land in their own private pond, reducing the dependence of evolved from a legged ancestor.
Caecilians live in a tropical environment for reproduction.

In contrast to the shell-less eggs of amphibians, the amni Most are found in damp habitats and some mammals have a shel.

The amniotes were able to occupy a wider range of habitats when they were adapted to drier habitats because they spent most of their time in burrows or under moist leaves.
The closest living relatives of the amphibians are the salamanders.
Most mammals have lost their eggshel.
In addition, typical y lay their eggs course of their evolution, and the embryo avoids desiccation in water or moist environments, and their eggs lack a salamander by developing inside the mother's body.

Over the past 30 years, zoologists have documented their rapid use of the rib cage.

This diagram shows the allantois exchange gases in the shell of the embryo.

The amnion protects the yolk.

The embryo in the fluid-filled cavity has its nutrients stored in the albumen cushions.

As a group they share several skin, but albumen use as a supplement to breathing through their diverged Amphibians.

Characters that distinguish them from other tetrapods may have been derived from the increased efficiency of rib cage ventilation.

Scales in reptiles conserve water by developing less permeable skin.

The scales help protect the animal's skin.

The egg is protected from drying out.

The amniotes lived about 350 million years ago.
The location of the eggshel is determined by where ternal y is.

Early amniotes were able to control their body temperature.

They do regulate their body temperature in a wide range of new environments.
Many lizards bask in the sun when the air resembles smal lizards with sharp teeth, a sign that they are cool and seek shade when the air is warm.
Predators were more accurate.

There are two large clades of body heat in Amniotes.

The reptile clade is more than just brates.
Birds are capable of maintaining groups, paying particular attention to their body temperature through metabolism.

Living members of the clade include tuataras, lizards focus here on birds, a diverse group of flying reptiles that arose and snakes, turtles, crocodilians, and birds.

Many of the characters of birds are adapted.

Birds lack a urinary bladder, saurs, and the females of most species have only one ovary.
Go birds are considered lizards.

Living birds are similar to lizards.

The toothless reptile trims the weight of the head.