Classification into reptile, bird or mammal game .
             Reptiles, birds, and mammals are all  examples of land-living (terrestrial) vertebrates, but there are a ton of  differences you can make out between a scaly crocodile, and, say, a graceful  peacock or a fluffy, little rabbit.
            Reptiles, birds, and mammals are all  examples of land-living (terrestrial) vertebrates, but there are a ton of  differences you can make out between a scaly crocodile, and, say, a graceful  peacock or a fluffy, little rabbit.
            
            As all of them are terrestrial creatures, reptiles  share a few crucial features with birds and mammals to help them survive and  reproduce on land. We’ll take a look at a few similarities. All three classes are part of a group called  the amniotes. The amnion, a membrane in the amniotic egg, was an evolutionary  adaptation that kept developing embryos from drying out. This allowed early reptiles  to lay eggs on land – a feature that was also passed down to mammals, and later  on, birds. Another shared feature is called internal  fertilization. Creatures with this trait reproduce with the male depositing  sperm into the female’s body to develop into offspring. One other neat adaptation that birds,  reptiles, and mammals share is that their feathers, scales, or skin contains a  waterproofed protein known as keratin to prevent dehydration. Of course, with all these similarities,  mammals, birds and reptiles still possess a lot of differences from each other.  Let’s take a look at how they birth offspring. Birds lay eggs which hatch into  chicks. Mammals, on the other hand, are notable for birthing live young. While  most reptiles, like crocodiles and turtles, lay eggs, most snakes and lizards  are viviparous – they birth live young as well. Mammalian skin also tends to have hair or  fur, and their blood is warm-blooded. Mothers feed babies with their own milk.  Birds have feathers, and are likewise warm-blooded. Reptiles possess scales,  and they need the sun to warm their bodies, being cold-blooded. Test out your understanding of the  similarities and differences among these three fascinating animal classes with  our
            
             classification into reptile, bird or mammal game
            
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There are several characteristics that can be used to classify organisms into the categories of reptile, bird, or mammal. Here are some of the key characteristics to consider:
Body covering: Reptiles have scaly skin, birds have feathers, and mammals have fur or hair.
Temperature regulation: Reptiles are cold-blooded, meaning they are unable to regulate their body temperature internally. Birds and mammals are warm-blooded, meaning they can regulate their body temperature internally.
Reproduction: Reptiles lay eggs, birds also lay eggs, and mammals give birth to live young.
Respiration: Reptiles and birds both breathe using lungs, while mammals can also breathe using lungs or through other specialized respiratory structures such as gills or a blowhole.
Skeletal structure: Reptiles and birds both have a skeleton that is largely made up of bone, while mammals have a skeleton that includes a spine and a skull.
By considering these characteristics, you should be able to classify most organisms into one of these three categories.