The dinosaur bit was originally supposed to just be some silliness that explained having them in A New and Ancient World, a rationale that became defunct when that died.
At the time I didn’t realize that T-Rex and Triceratops were indigenous to North America, and mainly the Great Plains and American West area, which makes it hard to explain how fossils of them got all the way to Constantinople. So OTL Carcharodontosaurus may be TTL Tyrannosaur to resolve that issue. Doesn’t explain Triceratops but that I’m willing to just handwave because, damnit, I think I’ve earned the right to handwave a few things.
Well those Triceratops fossils must have had a very long and arduous journey just to get to the Sideroi's collection. Considering the current relationship between the Empire of Mexico and the Roman Empire, then I think it's possible for Triceratops to realistically end up in Constantinople through budding Mexican or Roman paleontologists digging incomplete skeletons in New Mexico or Arizona, although it definitely would've cost them the big bucks. Luckily I think this happened before the crippling Roman depression so let's just leave it at that
Still, Odysseus the Magnificent is very unique even amongst his OTL historical counterparts because of his affinity towards dinosaurs, which is something that doesn't actually exist for Early Modern rulers since dinosaurs weren't discovered until the 1800s. Considering the larger than life character of Ody and his legacy being romanticized by Roman historians, I think they could play on this motif a LOT, since dinosaurs are simply awe-inspiring and terrifying to look at, so having a person be equated with something akin to a monster like Behemoth or Leviathan seems like what the Romans would do to Odysseus.
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Because the HRE is too weak after the Lotharingian invasion and the Great Latin War, I agree that they cannot commit a war with the Romans just yet. I don't think the HRE Emperor/Empress will even try for the next few decades, because taking back the Rhineland and Lotharingia from the Triunes seems more like a priority for the German court, despite the backlash from their own jingoist fanatics. Still, Vlachia is definitely something that the HRE will try to woo towards their side against the Romans through espionage and diplomacy, since the Vlachs despise the Romans for essentially forcing most of their countrymen into serfdom. A free Vlachia is not what Constantinople wants in the slightest, so I can definitely see a proxy war happen if a Vlachian revolution occurs, as the Romans will support a pro-Orthodox faction while the HRE and others could support an independent Vlachia that cuts ties with Romania.
While Vlachia has the potential to be an interesting region to look at for the future, the Triunes, Arles, and Russia are also places where we could see some immense changes happening to the continent. With all those changes happening while the Romans are withdrawing from European affairs, I can't help but think that Odysseus or his successors will be dragged back into the continent in some violent fashion, although that might not be the case. At the very least, having espionage and diplomacy becoming a more prominent part in 17th century politics in a Latin-Roman Cold War (mostly between the HRE and Romania) should make for an even more interesting time than it already has been.