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Re: Were dinosaur ecosystems continent-sized? (resend)

GSP1954@aol.com a écrit :
All the late Maastrichtian edmontosaurs are growth stages of E. annectens, with copei being the mature stage with long shovel grazing beaks that do not exist in specimens of 2 tonnes or less. Earlier E. regalis grew to the same final size of 3 tonnes, but the beak never elongates or squares off. The only major difference in the two taxa is the beak so Anatosaurus is a doubtful genus.
Do you mean 'genus', or 'species' ?
A genus IS doubtful if its type species is doubtful. If not, the genus MAY be considered as doubtful, and the type-species reallocated to another, close genus. The decision is up to the taxonomist, in this case. Here is a summary of what you just said, considering each genus and type species:

*Anatosaurus annectens* = *Anatotitan copei*
*Edmontosaurus regalis* =/= *Anatosaurus annectens*

Hence: *Anatosaurus annectens* = *Anatotitan copei* =/= *Edmontosaurus regalis*

Keeping *Edmontosaurus annectens* and *Anatosaurus annectens* as two valid (here taxonomically speaking) genera does not shok me, nor sinking *Anatosaurus* into *Edmontosaurus* (oops, I'm not too sure about this part of the sentence... Damn Frenglish !!). And, as I suppose you're also a cladist, you just have to be define your genera in a way that they are monophyletic. You could also sink the whole dinosauria into the same genus that it would not shock me. Well, it would a complete mess afterwards for bird and other dinos friends, but as long as the taxon is monophyletic...
It is interesting that a *hardosaur* clade was getting big into grazing when that dang asteroid simply ruined things.
A *hardosaur* ? I don't even want to know why such a name was erected...

Jocelyn Falconnet