3w ago

Today I learned that dinosaur secondary brains are not actually a thing

www.smithsonianmag.com

The Double Dinosaur Brain Myth

So I built a stegosaurus model kit, which included some factoids in the instructions. One of these factoids was that stegosaurs are not believed to have had a secondary brain in the hips to help them control their rear half after all. That was wild to me, since the whole stegosaurs and sauropods with their tiny heads needing a secondary brain for their huge bodies was commonly accepted back when I was a kid. So I looked it up, and indeed, the current hypothesis is that the cavity that the second brain was thought to occupy is used for a thing called a glycogen body. But what exactly does a glycogen body do? We'll get back to you on that, apparently.

57 comments

TIL a second hip brain was once a theory.
- If be interested to know where and when that was considered a fact, because I'm 45 and never heard that before.
  
  I'm 40 and remember being told that the Brontosaurus had multiple smaller brains down it's spine so that it could react to stimuli without having to wait for the signal to get all the way to its head and back.
  I also rember hearing at some point more recently that the Brontosaurus probably didn't exist. 🤷
  
  I'd heard of it.
- And could still be true.
  https://animaltriangle.com/animals-with-multiple-brains/
  Edit: See my later comment on more sources on bones. Fr guys, I have no idea either way, but if you're going to say my source is full of shit, provide your own legit sources to back you up.
  Edit 2: If you continue down this thread, there's a lot of trolling going on. This could be for 2 purposes, make me look like an unreliable source (on biology, that might be true) and ruin the vibe.
  
  I can’t speak for every creature in this source but practically everything it says about turtles is a straight fabrication. They have one brain. It’s oddly shaped but just one. Next, it’s in their skull, not their neck - that’s crazy. Finally, TURTLES HAVE BONES WTF
  
  What the fuck is that article? It's absolute nonsense. Like a first gen AI was trained on a single biology textbook.
  The mosquito brain has three main parts: the antennae, the maxillary palps, and the proboscis.
  Octopuses don’t have any real social structure like mammals do. Instead, they communicate through chemical signals. But these chemicals can transmit emotions just as effectively as words and they have two eyes.
  Animals with multiple brains include octopuses, cephalopods (squid), and even humans.
  The brain of a cuttlefish is located in the head, which is made up of two parts: the upper part contains the eyes, and the lower part contains the mouth.
  Cuttlefish is one of the smartest animals in the world. They are able to solve complex mathematical equations
  
  I mean, yes, but... What other vertebrates have developed a secondary brain? That's a big deal evolutionarily, considering all other vertebrates have the one.
  
  Not sure if you’re trolling or just a bit lost mate but you’re the only one who’s posted a source claiming turtles don’t have bones. Everyone else is aware that turtles have bones.
  E: Ah a troll after all. Started half good but honestly turned to shit pretty quick. 4/10. Turtles may have 1 brain but you, my friend, have 0.
  
  make me look like an unreliable source (on biology, that might be true)
  On what topics are you a reliable source?
  
  Edit 2: If you continue down this thread, there's a lot of trolling going on. This could be for 2 purposes, make me look like an unreliable source (on biology, that might be true) and ruin the vibe.
  lmfao are you fucking joking? you made yourself look like an unreliable source by referring to such a dogshit website/article. it actually required zero help from anybody else to shoot your credibility.
  
  it's at least true for me tbh
  
  May I ask how you found this absolute train wreck of a website?
TIL people used to think that dinosaurs had a 2nd brain
I've never heard of the "second brain" thing
That doesn't make any sense
- It was a thing when I was a kid. The older you get the more of your basic education gets proved wrong.
  
  Public school is great
  When I was a kid they told me that different parts of the tongue have different taste buds
  
  A surprising amount of teachers work like LLMs. No idea what they are talking about but extremely scared of admitting it.
- There’s some precedent for it in octopi. They have “distributed” intelligence, where each arm has a dedicated nerve cluster “brain” that controls it.
- I remember being told in school that Brontosaurus had a second brain because they were so big it would take to long for the impulses from their head to go to their tail.
  
  Giraffes elephants and whales might have something to say there but frankly we've thought weirder stuff.
Glycogen is an energy storage molecule that is more easily accessible (easier to convert into glucose, what your cells actually burn) by the body than fat is. I would assume this organ was a dedicated store for it.
Edit: ah that’s what I get for commenting before reading the damn article. Scientists haven’t confirmed that it’s definitely an energy storage organ, but it’s one of the leading theories.
- I can anecdotally confirm as a "dinosaur kid" of the 80s, that this was a common tidbit in children's books of the era.
  I'm pretty sure I had a VHS with Fred Savage where they ran through it as well.
  The explanation was that the response time if a Brontosaurus got its tail messed with (an anvil dropped on it) was problematicly slow if the nervous system had to send the message such a great distance to the "head brain" and then have the reaction message all the way back. Basically they'd be living with massive lag IRL.
  Can't say I'm surprised that science is backing off the certainty on that. Those same books were also full of "look at all the goofy things previous generations of paleontologists thought"
  
  I’m pretty sure I had a VHS with Fred Savage where they ran through it as well.
  Dinosaurs! (1987)
  Link to relevant scene (starts ~17:05)
  
  The explanation was that the response time if a Brontosaurus got its tail messed with (an anvil dropped on it)
  If a Brontosaurus needed to react to an anvil being dropped on its tail then I have more important questions.
  
  People then were smoking cigarettes so who knows
  
  Doesn't that already happen in the spine?
My Dad would say I have a brain in my ass because my head was always up there.
Not an expert in the field, but my understanding was there are parts of our own upper spinal cord/lower brain that handle very basic controls. For a much larger body could there just be a larger part like this for simple subconscious and reactionary commands?
- Not upper, though. All through the spinal chord.
Also brontosaurus is a separate species again, microraptos were black and anurognathus is extremely cute
... was this just someone taking the "smart-ass" joke a bit too far?
/s
what about octopus secondary hearts? human secondary brains?
- Our digestive system has an extremely complex autonomous nervous system called the enteric nervous system (ENS), which is sometimes referred to as the "second brain". So technically yes.

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