Of course that's correct. But the other pronunciation is not incorrect; it's just less correct, because it elides over the root boundary between the archaeo- for "ancient" and -pteryx for "winged one".
I recall hearing or seeing the less-correct pronunciation near the relevant fossil or fossil reproduction at the Chicago Field Museum of Natural History, but I can't remember if it was actually printed on the display card or not. I did have to explain to my kids why the correct pronunciation of root-combining words is important for effective communication. The exaggerated roll of the eyeballs means you're teaching it effectively! (Or at least that's what I keep telling myself.)
I recall hearing or seeing the less-correct pronunciation near the relevant fossil or fossil reproduction at the Chicago Field Museum of Natural History, but I can't remember if it was actually printed on the display card or not. I did have to explain to my kids why the correct pronunciation of root-combining words is important for effective communication. The exaggerated roll of the eyeballs means you're teaching it effectively! (Or at least that's what I keep telling myself.)