Via Nobu Tamura
OK, yes -- today's whales are plenty huge. We're aware of this; we're also aware that they used to be a lot bigger. And meaner.
Via Wikimedia Commons
That's the Basilosaurus, otherwise known as the Joker's favorite fish. At over 80 feet long, it dwarfed the killer whales of today, which only average 25 feet or so in length. So yeah, you'd need three Shamus, plus your terrified, piss-stained ass, to equal the Basilosaurus in stature.
When its remains were discovered in Louisiana in 1832, it was mistakenly identified as a sea monster, and given a name that literally translates to "king of the reptiles." They forgot to tell people that this thing went extinct quite a while ago, and so local fishermen shat themselves over the thought of a gigantic monster lurking in the same waters they used to find ingredients for catfish gumbo.
They wanted 25 cents to see that thing? What a ripoff. Wasn't that like the price of a house back then?
Luckily for them, Basilosaurus doesn't exist anymore; if it did, the fishermen would be the gumbo. That jawline would make Basilosaurus a top predator in any time period. Set the time machine forward 20 million years, and it would be duking it out with Livyatan melvillei and Megalodon, no slouches themselves. Another 15 million years, and it would be chewing up Jaws like Jaws would chew up a mackerel.
Even today, it would take one look at the 100-foot, 170-ton blue whale, realize it's just a big teddy bear unless you're, say, a piece of plankton, and swim off all smug-like, knowing the delicious dishes of the sea are still available, and still all for him.
"Mmmm. After-dinner mint."
Tom Brakefield/Stockbyte/Getty Images
The Cretaceous Period was evolution's experimental phase, where it decided to stick just a fuck-ton of big, evil, monstrous creatures on Earth at once, just to see what would happen. Even by that period's standards, Sarcosuchus imperator stuck out. Its name translates to "flesh crocodile emperor," and that might actually be an understatement. This was a 40-foot-long, 10-ton monstrosity that regularly ate dinosaurs. We're going to repeat that last part, because it bears repeating. IT ATE DINOSAURS. BIG ONES.
Like modern crocodiles, they spent most of their time half-submerged in water, waiting for something edible to come by. Unlike modern crocs, they had to find a way to submerge 40 feet of scaly flesh under that water. This wasn't always easy, so much of Sarcosuchus' diet consisted of easy-to-catch fish. However, if a dumbass dinosaur just happened to roll along, it wasn't about to let such an incredible feast pass by unscathed.
It's one step from burying itself in the sand vertically, like Sarlacc from Star Wars, and waiting for shit to fall in.
Unfortunately, an epic Sarcosuchus/T. rex battle exists only in the minds of SyFy original movie writers (if it didn't, it does now), as Sarcosuchus died out about 40 million years before Barney and friends arrived. Fret not, though, as Spinosaurus, the largest land predator of all time, lived right alongside our giant croc friend; the two of them almost certainly did battle at one point or another.
Sadly, everybody forgot their camera that day, so we can only imagine how the fight went down, and how quickly this pornographically huge crocodile made the silly Spinosaurus his breakfast.
If we had to guess at a time frame, though, we'd bank on "pretty fucking fast."
For more reasons you don't want a time machine, check out 7 Thankfully Extinct Giant Versions of Modern Animals and 8 Prehistoric Creatures Ripped Directly from Your Nightmares.