3 questions in relation to kpg

My first question is something I was recently wondering about, is T-rex able to swim? If so how well?
Second, a book I’ve read talks about a dark layer of clay being formed when sea life almost disappeared because of the KPG impact. Any idea on what this layer is, the name of it, papers on it, and there are pictures of it.
Third, a book I’ve read talks about a layer and small particles of charcoal that was created by forest fires by the KPG impact. Any idea on what it is, and the name of this?

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Hiya Liz!
Try this for starters:


I see claims they could swim quite well, but I was not able to find a scholarly source in a quick search.

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To answer your second and third questions directly: the clay layer is called the K/T boundary clay, a direct result of small particles of asteroid ejecta settling out of the air worldwide. It also, in some places, contains charcoal from the forest fires started by the impact. In at least one place (the Hell Creek Formation), it contains fossils of organisms killed on or near the date of the impact.


It’s also called “fish clay”, and you can find lots of pictures of it by just googling “K-T boundary fish clay”. Denmark (where I’m from) has a famous fossil site at Stevns Klint where the layer is exposed and can be easily seen:


IMHO, the coolest rocks are the large ones that formed from molten ejecta that cooled in the atmosphere. Their teardrop shape is a witness to the catastrophe.


Of course T rex couldn’t swim. Could you swim without any arms? Even if it had a powerful hind end + tail its head would sink. Just consider some simple biomechanics.

Head nowhere as big in proportion to body as T. rex

Ahh, the argument from “I can just sorta feel it wouldn’t work”.

Yup. That’s worked for me in over half a century of doing functional morphology science. Of course, one has to back up that sort of intution with actual analyses (data, quantification, etc.), but that can be done (not about to do that here with this example). That’s how all good scientists work, having that gut feeling and then acting on it.

What about this picture tells you that this critter was a regular swimmer? (I’m not talking about somehow being able to survive if pitched into tthe water, which I don’t believe was the original question.) Other than just being ornery, of course,

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And yet you thought a person without arms can’t swim.

At least one paleontologists thinks they could. This research is far from conclusive. :slight_smile:

PS: The Museum of Northern Arizona is small but well worth a visit, especially for the Peoples of the Colorado Plateau room.

It’s certainly not the norm. And so not relevant to the broader question.

Well you’re the one who invoked not having arms as a reason for not being able to swim in the first place. And clearly your intuitions aren’t all that, then.

Also, T-rex had a rather long tail to counterbalance the weight of it’s head which would be rather useful for swimming. Whether it swam “regularly” isn’t relevant at all. The question is if it could. You say no, and you just haven’t provided any good reason to think you’re in a position to know at all. My intuitions are no worse than yours, and I think it could do it rather well. What now?

When Dave Gillette does the computational fluid biomechanics to show that T. rex could swim, then I’ll listen. Meanwhile, his hearsay comments are no better than mine. Actually worse, because he has no record of research in biomechanics.

Not to mention snakes.

Nonetheless, if I were being chased by a T-Rex, I would take my chances in water, because I know he can run.

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Long, fatty tail might balance things out. (@Rumraket beat me to it)

Calling dibs on coining the term “T. rexy paddle”.


This guy seems to swim fine without any legs or arms. Has a chubby body and long tail, though.

Actual GoPro picture…

Apple TV+ series ‘Prehistoric Planet’ features a swimming Tyrannosaurus rex

Even if T-Rex did not swim like a stone, they do not seem to have crossed the Western Interior Seaway into Appalachia, so they did not do long distance.

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