DrDirtPhD

DrDirtPhD t1_j551hg3 wrote

We're all just fish anyway.

Seriously though, synapsids and sauropsids share a common ancestor but are two distinct monophyletic sister lineages. Synapsids gave rise to mammals and sauropsids to reptiles (including birds which are just highly derived reptiles).

Your question just seems to be one of nomenclature rather than taxonomy/systematics though. Reptiles are reptiles from cultural carryover, even though classically the definition is paraphyletic (by excluding birds it doesn't include all descendant species of a common ancestor); in modern systematics it includes birds and makes a single clade. Mammals are a distinct monophyletic grouping and so remain a valid clade.

Changing amniote to reptile and synapsids to "mammal like reptiles" and sauropsids to "lizard like reptiles" doesn't add any clarity to things, and because lizards/birds/snakes/turtles are all fairly distinct groupings on their own it actually muddies the definition some.

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