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by sorokod 36 days ago
>the avian lineage had split from crocodiles

Aren't crocodiles and dinosaurs seperarte branches ?

2 comments

They have common ancestors, but it really should be "the crocodiles had split from the avian lineage", with avians including dinosaurs at that moment in time
A split is a split. Archosaurs split into a crocodile line and a dinosaur/bird line--"the avian lineage" (birds being a kind of dinosaur, and the only ones still living) ... that's what "the avian lineage had split from crocodiles" means -- it is not saying that birds are an offshoot from crocodiles, it's saying that the two lines (both kinds of archosaur) split from each other. Likewise, crocodiles are not an offshoot of dinosaurs.
The funny thing is that it would make more sense (going by our popular impression of what dinosaurs looked like) if dinosaurs were in the same lineage as crocodiles, not birds.
Note the word "lineage". That would include the dinosaurs that were ancestors of birds. Birds are dinosaurs, so reword the statement as

> the dinosaurs had split from crocodiles

Birds and crocodiles are both archosaurs (which includes all dinosaurs as well as crocodiles) and are each others' closest living relatives.