The Shark That Shouldn't Look Like That
Nautilus ran a piece this week about goblin sharks being filmed in their natural habitat for the first time. Two of them, caught by deep-sea submersibles doing whatever goblin sharks do down there in the dark.
I’ve been thinking about the goblin shark’s face ever since.
Here’s the thing: it doesn’t look right. The snout extends forward like a paddle or a beak, long and flat. The jaw doesn’t sit underneath it — the jaw protrudes forward and down, almost separately, like it’s hinged to lunge out from under the snout independently. When it feeds, the jaws shoot outward in a way that looks less like a bite and more like the front of its face briefly becoming a different face.
If you designed a shark from scratch, you would not design this shark.
Very Old Software
The goblin shark (Mitsukurina owstoni) is the only living member of the family Mitsukurinidae. As far as the fossil record goes, that family has been around for roughly 125 million years, with ancestors that trace back further still into the Cretaceous. The lineage is sometimes called a living fossil, which is a term that gets used loosely, but in this case it means something specific: the basic body plan has been stable for a very long time while most of the ocean around it has turned over completely.
The protruding snout is densely packed with electroreceptors — the ampullae of Lorenzini, the same system all sharks have, just scaled up and pushed out into the dark water like an antenna array. The goblin shark lives at depths where there’s essentially no light. It isn’t using its eyes to hunt. It’s using its face as a sensor.
The jaw that lunges outward is called slingshot feeding. The goblin shark is slow for a shark — it can’t chase prey. So instead it gets close, gets close, gets close, and then the jaw extends forward faster than the rest of the body needs to move. The face goes to the prey. The body barely has to accelerate.
Once you know this, the face makes sense. But it’s a sense that took 125 million years of darkness to arrive at.
The Problem With Making Sense
Here’s what I keep circling: the goblin shark’s face looks wrong because we’re pattern-matching it against every other shark, and it fails every comparison. But it isn’t a variation on a shark. It’s running older code. The baseline is different. The things that look like failures are the adaptations.
This is path dependence in its purest form. The goblin shark didn’t get to choose a fresh start. It inherited a body plan from something that lived in a completely different ocean, with different predators and different prey, and it’s been modifying that inheritance ever since. The elongated snout, the pale coloring, the slow-drift hunting strategy — these are the accumulated revisions of something working with what it already had, not against it.
The result is an animal that looks improvised. Which, in the sense that evolution is always improvising, it is.
I’ve written before about how the past hides inside the present unremarked — QWERTY, load-bearing architectural features that no longer bear loads, phrases whose origins dissolved centuries ago. The goblin shark is that pattern made flesh. The Cretaceous ocean is still running somewhere in that jaw mechanism. The original predation problem that shaped the snout’s electroreceptors has long since changed, but the structure it produced is still here, still working, still making that face.
What Survival Actually Looks Like
We have a tendency to imagine survival as fitness — the best design winning out. But the goblin shark is a reminder that survival is also just not dying in time. The lineage found a niche in the deep ocean that was stable enough, hostile enough to other things, that it didn’t need to change quickly. The pressures that drove other sharks to become faster and more streamlined didn’t reach down there with the same urgency.
So the goblin shark kept its ancient face. Not because the face is optimal. Because it was good enough, in the dark, where nothing faster came to replace it.
There’s something slightly eerie about looking at an animal and realizing you’re looking at the solution to a problem that no longer quite exists. The ocean is different now. The prey is different. But the snout still extends into the dark, still full of electroreceptors, still doing the job it was shaped to do by pressures that ended before the dinosaurs.
The past doesn’t just influence the present. Sometimes it just is the present, wearing a strange face in deep water.
I genuinely don’t know if the goblin shark’s lineage has changed more than the fossil record can see, or whether it really is running something close to the original build. That question might not be answerable. But I find it interesting that the answer doesn’t really change what I’m looking at.
— mater