Can't really say a lot of these fights would work, simply because we don't even know if Spino was a swimmer, let alone a good one. Chances are it wasn't a submersible predator like the image portrays, so it wouldn't get past maybe the Bull Shark imo.

But assuming it was at least a decent swimmer and the opponents can handle the changes in pressure/depth/salinity, I'd say it loses at the giant squid.

^A Spinosaurus... losing to a giant squid? Even with more conservative estimates, Spinosaurus weighs 7 tons. A giant squid only weighs 495 kg so there's no way it's winning this.

I'm an ocean fanatic and I say Spinosaurus stomps everything here except the killer whale. I don't really see how a Spinosaurus can realistically kill a healthy orca, even if they are about the same size.

I'm thinking more about the serrated edges on the squid's arms would mess up a Spinosaurus to the point it risks bleeding out imo. On a sperm whale it matters less because of its thick hide and blubber, and even then, they get messed up pretty bad. Spinosaurus lacks this luxury and is much smaller. Would it be a stomp? No, but that round is where risk of death is noticeable enough to call it.

The Killer Whale would maul the spino to death, other's aretoo small to really threaten it.

The average killer whale weighs 5 tons, while it's 7 tons for Spino. Both of their max weights are around the same. While I think an orca would win, I wouldn't call it a stomp because the Spino can inflict serious damage if the orca is not careful. A killer whale's blubber is around 10 centimetres in the thickest regions, and a Spinosaurus's teeth and claws are long enough to pierce that.

Since it's a singular orca, it won't have a pack advantage. Orcas primarily kill their prey by drowning, with biting only playing a minor role. Orcas are also overhyped in Who Would Win scenarios. For example, it takes 50 orcas to take down a blue whale. I once saw someone claim that 3 orcas could take down a 60-foot Megalodon, which is just absolutely ridiculous.

Now why do I think the orca would win? That's mostly because it has the mobility advantage and I don't really see how a Spinosaurus could effectively take one down in open water, whereas it could just kill the others by biting and clawing. In a realistic scenario, there would be no fight since a Spinosaurus wouldn't bother hunting something that big and fast and a lone orca wouldn't take on something that large.

@KirbyCountryReturns @ScaryLookinHobo

Normal Giant Squids literally live at depths with a pressure that would crush anyone. If they decide to surface they would be vulnerable. They only do so at the darkest times of the night. So...

My verdict was ignoring the changes in pressure/depth/salinity/etc., but if we were being realistic, that squid would die far before it gets to the Spino

^

I see Giant Squids are able to surface but only for limited amounts of time on darkest hours.

Idk what would a Spinosaurus would do middle of an ocean on such an occasion. They ( so far / for now ) not pilot whales Nor sperm whales :/

Great white female

Spinosaurus probably demolishes the whole thing, and maybe stops at orca

I'm not certain about orca, but if the orca gets to ram the spino beforehand, victory is plausible.

Oops sorry for necropost