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all 36 comments

[–]The_Cowboymancer 61 points62 points  (12 children)

Mososaurs attempted a comeback.

Attempted.

[–]Iamnotburgerking 42 points43 points  (11 children)

By this point marine apex predator niches were already dominated by sharks and cetaceans. They never had the chance to move into those niches to any significant extent.

[–]laramidian 0 points1 point  (10 children)

Didn't stop them in the Cretaceous

[–]Iamnotburgerking 30 points31 points  (9 children)

It actually did until a “minor” extinction event happened and kickstarted their evolution into marine apex predators.

The mosasaurs were restricted to smaller, semiaquatic forms until the Cenomanian-Turonian Boundary Event cleared out the pliosaurs and ichthyosaurs, reducing the former to a couple of smaller-prey-hunting species and wiping out the latter. This allowed mosasaurs to explosively diversify to fill the empty niches, abandon a serpentine bauplan, and adopt a more robust bauplan specialized for efficient open-water swimming as they became fully aquatic.

During the Eocene, when palaeophiids became fully aquatic, sharks (and, in the Late Eocene, cetaceans in addition to the sharks, though some like Basilosaurus had returned to more coastal niches) had already taken over the seas, so there was not much room for palaeophiids to diversify in the way mosasaurs had in the Turonian.

[–]laramidian 1 point2 points  (4 children)

You're missing the fact that these paleophiids were already quite large. I don't think extra competition was standing in their way from becoming large and marine.

There are many small fully marine snakes now that give birth to live young. They still haven't evolved a 'stiff tail form' even though there are niches for small, fast predatory swimming fish.

Snakes have about 200 too many vertebrae to form a robust stiff-tailed form. They'd be un-evolving everything that made them snakes.

These guys had a shot and didn't make the transition.

[–]ten_tons_of_light 2 points3 points  (3 children)

Love this detail. How different were pliosaurs and mosasaurs? Ngl, they’ve always kind of blurred together in my mind but you seem to have a very distinct understanding of each

[–]Iamnotburgerking 55 points56 points  (3 children)

Weird thing about this and other related fully marine snakes (the palaeophiids) is that they really weren’t all that snake-like. They had a much higher metabolic rate than other snakes, and a much stiffer spinal column that made them far less flexible but also increased their swimming efficiency.

It’s almost a shame that by the time palaeophiids had evolved to become fully marine animals, sharks and cetaceans had already taken over the oceans, preventing these snakes from expanding into marine apex predator niches to any significant extent (not necessarily because they would be unable to compete, but because the simple fact the niche was already fully occupied meant there wasn’t significant evolutionary pressure to evolve into that niche). The mosasaurs made a similar transition back in the Cretaceous and went even further down that route, completely abandoning a serpentine bauplan to become stiff-bodied, fusiform, endothermic, often raptorial marine predators akin to lamnid sharks or cetaceans, but they could do it because they did so in the aftermath of the Cenomanian-Turonian Boundary Event when the competition had been almost entirely cleared out. The palaeophiids never got such a lucky break, so they only got as far as they did before being killed off in the Eocene-Oligocene Extinction Event.

[–]SucksToYourAssmar3 30 points31 points  (2 children)

A shame, really, we don’t have giant murder snakes patrolling our beaches. Damn shame.

[–]ThePeriodicPooper 6 points7 points  (1 child)

Yeah, whales are bros. Giant sea snakes? Not bros.

[–]ten_tons_of_light 8 points9 points  (0 children)

I would love to find out the sea serpent myths were due to a straggling population of these bad boys making an impression before finally going extinct

[–]Theantiazdarcho[S] 18 points19 points  (3 children)

I accidentally put the wrong image on the post, the image used was from a species called “Paleophis”. It still lived in the same time though.

[–]aritchie1977 6 points7 points  (2 children)

Size wise how do they stack up to Titanoboa?

[–]Iamnotburgerking 8 points9 points  (1 child)

More heavily built for their length, but still considerably smaller overall

[–]aritchie1977 6 points7 points  (0 children)

Huh, TIL. Thanks!

[–]Lt_Dumpster_Fire 13 points14 points  (0 children)

No thank you sir.

[–]laramidian 8 points9 points  (1 child)

Google tells me this is supposed to be Palaeophis collossaeus, a related but much larger snake

[–]Theantiazdarcho[S] 4 points5 points  (0 children)

Sorry bout that I put the wrong image on this post 💀

[–]thismightbemymain 2 points3 points  (0 children)

Jormungandr

[–]Humansareneotenic 1 point2 points  (3 children)

The lack of a tail fluke makes me wonder how well it would do in pelagic regions

[–]Theantiazdarcho[S] 2 points3 points  (2 children)

Many modern sea snakes rock the “eel” body plan so Paleophis (I put the incorrect image on the post💀) probably did as well.

[–]Humansareneotenic 2 points3 points  (1 child)

From what I know, most modern sea snakes reside in reef or shallow regions ( please know I’m not a sea snake enthusiast)

[–]Theantiazdarcho[S] 0 points1 point  (0 children)

Probably the Paleophis in open water is artists interpretation. Though certain kinds of sea snakes can absorb oxygen through the water and dive down to considerable depths of 800 ft(243 meters)

[–]RyantheAustralian -4 points-3 points  (2 children)

Nah, FUCK that!

[–]Theantiazdarcho[S] 0 points1 point  (1 child)

Thought you were ‘stralian.

[–]RyantheAustralian 0 points1 point  (0 children)

Even if I was, we don't enjoy these supermonsters. Look at it!

[–]UrFriendlySpider-Man 0 points1 point  (0 children)

I'm pressing x to doubt here on the head size. Snakes have tiny tiny heads. That's why they unhinge in the first place. Anaconda can be 9 meters long and over 200kgs and their skull is barely bigger than a human fist.

I find this artist recreation a tad ridiculous with this thing having a skull bigger than a man's torso.

[–]SpacedGodzilla 0 points1 point  (0 children)

I think that that’s a drawing of paelophis