Ideally birds evolved from Dinosaurs, but they are closely related to even reptiles. Biologists use 2 types of classification system: According to the Linnaen system, organisms are grouped on the basis of their characteristics without considering their ancestry. Based on this a reptile is an animal that is ectothermic and consists of scales, and thus birds cannot be reptiles. While in Phylogenetics,organisms are grouped only on the basis of their ancestry, and characteristics are only used to discover this ancestry. So based on this a reptile is any animal descending from reptiles, and birds (including mammals) would be considered as reptiles. Looking back at history, the 1st group of reptiles evolved around 300 million years ago. Around 40 million years later, a group of reptiles called therapsids branched off, that became modern mammals. Another group of reptiles split off in the next 120 million years, and one branch called the dinosaurs was very successful. Dinosaurs was only distantly related to modern snakes, lizards, and turtles, groups that had split off at different times. But 65 million years ago there was a massive extinction event, and all dinosaurs were killed except for a single group of feathered dinosaurs. These evolved over the next 65 million years into modern birds. So birds aren\'t just closely related to dinosaurs, they really are dinosaurs! This is what most people mean when they say that birds are reptiles, although technically according to the phylogenetic system mammals are also reptiles. Birds and reptiles are both vertebrates and are alike in ways: 1. They both lay eggs which have a protective shell. This is an adaptation to prevent drying-out, necessary in evolution before vertebrates could lay their eggs on land. 2. Both birds and reptiles have lungs and thus breathe air. 3. Both birds and reptiles have scales on their skin. In birds, most of the body is now covered with feathers, which are modified scales. You can still see the scales on birds\' legs. 4. It is thought that birds evolved from reptiles. These probably were able to fly as well. Birds and reptiles differ in ways such as: While most reptiles are ectothermic (\"cold blooded\"), birds are endothermic (\"warm blooded). Thus birds have mechanisms like mammals that enable them to maintain a body temperature that is independent of their surroundings. Their feathers and their high metabolic rate help keep them warm in cold environments, for example. While reptiles have a 3-chambered heart, birds have a 4-chambered heart. This allows them to be more efficient, as the deoxygenated blood from the tissues is completely separated from the oxygenated blood from the lungs.While reptiles have teeth, birds do not. They grind their food in an organ called the gizzard. Solution Ideally birds evolved from Dinosaurs, but they are closely related to even reptiles. Biologists use 2 types of classification system: According to the Linnaen system, organisms are grouped on th.

1. Ideally birds evolved from Dinosaurs, but they are closely related to even reptiles. Biologists use
2 types of classification system:
According to the Linnaen system, organisms are grouped on the basis of their characteristics
without considering their ancestry. Based on this a reptile is an animal that is ectothermic and
consists of scales, and thus birds cannot be reptiles.
While in Phylogenetics,organisms are grouped only on the basis of their ancestry, and
characteristics are only used to discover this ancestry. So based on this a reptile is any animal
descending from reptiles, and birds (including mammals) would be considered as reptiles.
Looking back at history, the 1st group of reptiles evolved around 300 million years ago.
Around 40 million years later, a group of reptiles called therapsids branched off, that became
modern mammals.
Another group of reptiles split off in the next 120 million years, and one branch called the
dinosaurs was very successful. Dinosaurs was only distantly related to modern snakes, lizards,
and turtles, groups that had split off at different times.
But 65 million years ago there was a massive extinction event, and all dinosaurs were killed
except for a single group of feathered dinosaurs. These evolved over the next 65 million years
into modern birds. So birds aren't just closely related to dinosaurs, they really are dinosaurs!
This is what most people mean when they say that birds are reptiles, although technically
according to the phylogenetic system mammals are also reptiles.
Birds and reptiles are both vertebrates and are alike in ways:
1. They both lay eggs which have a protective shell. This is an adaptation to prevent drying-out,
necessary in evolution before vertebrates could lay their eggs on land.
2. Both birds and reptiles have lungs and thus breathe air.
3. Both birds and reptiles have scales on their skin. In birds, most of the body is now covered
with feathers, which are modified scales. You can still see the scales on birds' legs.
4. It is thought that birds evolved from reptiles. These probably were able to fly as well.
Birds and reptiles differ in ways such as:
While most reptiles are ectothermic ("cold blooded"), birds are endothermic ("warm blooded).
Thus birds have mechanisms like mammals that enable them to maintain a body temperature that
is independent of their surroundings. Their feathers and their high metabolic rate help keep them
warm in cold environments, for example.
While reptiles have a 3-chambered heart, birds have a 4-chambered heart. This allows them to
be more efficient, as the deoxygenated blood from the tissues is completely separated from the
oxygenated blood from the lungs.While reptiles have teeth, birds do not. They grind their food in

2. an organ called the gizzard.
Solution
Ideally birds evolved from Dinosaurs, but they are closely related to even reptiles. Biologists use
2 types of classification system:
According to the Linnaen system, organisms are grouped on the basis of their characteristics
without considering their ancestry. Based on this a reptile is an animal that is ectothermic and
consists of scales, and thus birds cannot be reptiles.
While in Phylogenetics,organisms are grouped only on the basis of their ancestry, and
characteristics are only used to discover this ancestry. So based on this a reptile is any animal
descending from reptiles, and birds (including mammals) would be considered as reptiles.
Looking back at history, the 1st group of reptiles evolved around 300 million years ago.
Around 40 million years later, a group of reptiles called therapsids branched off, that became
modern mammals.
Another group of reptiles split off in the next 120 million years, and one branch called the
dinosaurs was very successful. Dinosaurs was only distantly related to modern snakes, lizards,
and turtles, groups that had split off at different times.
But 65 million years ago there was a massive extinction event, and all dinosaurs were killed
except for a single group of feathered dinosaurs. These evolved over the next 65 million years
into modern birds. So birds aren't just closely related to dinosaurs, they really are dinosaurs!
This is what most people mean when they say that birds are reptiles, although technically
according to the phylogenetic system mammals are also reptiles.
Birds and reptiles are both vertebrates and are alike in ways:
1. They both lay eggs which have a protective shell. This is an adaptation to prevent drying-out,
necessary in evolution before vertebrates could lay their eggs on land.
2. Both birds and reptiles have lungs and thus breathe air.
3. Both birds and reptiles have scales on their skin. In birds, most of the body is now covered
with feathers, which are modified scales. You can still see the scales on birds' legs.
4. It is thought that birds evolved from reptiles. These probably were able to fly as well.
Birds and reptiles differ in ways such as:
While most reptiles are ectothermic ("cold blooded"), birds are endothermic ("warm blooded).
Thus birds have mechanisms like mammals that enable them to maintain a body temperature that
is independent of their surroundings. Their feathers and their high metabolic rate help keep them
warm in cold environments, for example.

3. While reptiles have a 3-chambered heart, birds have a 4-chambered heart. This allows them to
be more efficient, as the deoxygenated blood from the tissues is completely separated from the
oxygenated blood from the lungs.While reptiles have teeth, birds do not. They grind their food in
an organ called the gizzard.