class Amphibia vs amphibia

class Amphibia and amphibia both are nouns.

Word	Noun	Adjective	Verb	Adverb
class Amphibia	Yes	No	No	No
amphibia	Yes	No	No	No

As nouns, class Amphibia and amphibia are synonyms defined as:

class Amphibia and amphibia: the class of vertebrates that live on land but breed in water, frogs, toads, newts, salamanders, caecilians

class Amphibia (noun)	amphibia (noun)
the class of vertebrates that live on land but breed in water, frogs, toads, newts, salamanders, caecilians	the class of vertebrates that live on land but breed in water, frogs, toads, newts, salamanders, caecilians