Brian Switek on Edmontosaurus

[suspsy]

https://omni.media/the-dead-zoo-edmontosaurus

Wasn't aware that Ugrunaaluk had been reclassified as Edmontosaurus. Too bad, it was a cool name. And someone really needs to release a toy with the head comb!

[Pachyrhinosaurus]

It's interesting that the picture has an edmontosaurus with iguana-like spines. Is that new or is it speculation? I've only ever seen squareish spines on hadrosaurs.

[Dinoguy2]

It's interesting that the picture has an edmontosaurus with iguana-like spines. Is that new or is it speculation? I've only ever seen squareish spines on hadrosaurs.

I think it's speculation. Showing square spines on all hadrosaurs is wrong - that's the kind seen on Brachylophosaurus, but other hadrosaurs have different shapes or no spines or a continuous ridge (like in Edmontosaurus annectens). There seem to have been as many varieties of dorsal ridges as there were crests.

[Pachyrhinosaurus]

It's interesting that the picture has an edmontosaurus with iguana-like spines. Is that new or is it speculation? I've only ever seen squareish spines on hadrosaurs.

I think it's speculation. Showing square spines on all hadrosaurs is wrong - that's the kind seen on Brachylophosaurus, but other hadrosaurs have different shapes or no spines or a continuous ridge (like in Edmontosaurus annectens). There seem to have been as many varieties of dorsal ridges as there were crests.

I was never sure whether the single ridge or individual spines was preferred. If the continuous ridge was found on E. annectens, would that mean that that's the least speculative option for E. regalis?

[Dinoguy2]

It's interesting that the picture has an edmontosaurus with iguana-like spines. Is that new or is it speculation? I've only ever seen squareish spines on hadrosaurs.

I think it's speculation. Showing square spines on all hadrosaurs is wrong - that's the kind seen on Brachylophosaurus, but other hadrosaurs have different shapes or no spines or a continuous ridge (like in Edmontosaurus annectens). There seem to have been as many varieties of dorsal ridges as there were crests.

I was never sure whether the single ridge or individual spines was preferred. If the continuous ridge was found on E. annectens, would that mean that that's the least speculative option for E. regalis?

Not necessarily. Saurolophus and Brachylophosaurus bracket Edmontosaurus and they both have separated ridges so that was probably the ancestral condition (though the shapes of the spines were different in both and S. osborni seems to have lacked any ridge). So  Edmontosaurus regalis could have had a connected ridge or could have still had the ancestral separated ridge.