Timeline for Why would this creature have a head?
Current License: CC BY-SA 4.0
18 events
| when toggle format | what | by | license | comment | |
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| Apr 6, 2021 at 20:48 | vote | accept | Ichthys King | ||
| Apr 2, 2021 at 9:06 | comment | added | nzaman | From the diagram, the head appears to be independent of the pharynx. Are they supposed to be connected? If the primary function is to contain the brain, then perhaps its existence is due to the combination of armour plating and heat dissipation, as in vertebrates. The heavy bone structure encapsulating the brain would limit movement in the torso, and the brain needs to lose heat, so the brain pan needs to be outside the main body | |
| Apr 2, 2021 at 7:37 | comment | added | Ichthys King | @nzaman The head is a structure containing the brain that sits in front of the pharynx | |
| Apr 2, 2021 at 6:18 | comment | added | nzaman | What is a "head"? A container for the brain? A protuberance at one end of the body? A counterweight? What makes it distinct? Why can't we call it a tail, for instance? | |
| Apr 2, 2021 at 5:37 | answer | added | Trioxidane | timeline score: 1 | |
| Apr 1, 2021 at 23:15 | comment | added | DKNguyen | @IchthysKing I guess those are the closest examples, but I don't think their heads were ever very distinct from their bodies the same way tetrapods have necks. Eurypterids and their descendents, scorpions, arachnids, lobsters and shrimp never seemed to have a mammal-like neck or a very distinct head to begin with. Only insects seem to. | |
| Apr 1, 2021 at 21:49 | comment | added | Ichthys King | @DKNguyen Arachnids and crabs have lost their heads in a way, and heads will be detrimental because they stick out in front of the animal, where they are easy to strike | |
| Apr 1, 2021 at 21:45 | history | edited | Ichthys King | CC BY-SA 4.0 |
added 87 characters in body
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| Apr 1, 2021 at 21:41 | answer | added | John O | timeline score: 6 | |
| Apr 1, 2021 at 21:31 | comment | added | G0BLiN | Joining on the request of some drawing - This sounds very intriguing, butI can't understand how a creature could at the same time be "similar to velvet worms" (which crawl like a caterpillar or slug, I think?), have a "wing-less bird's stance" (so, bipedal? but is it like a velociraptor, an ostrich, a dodo or a penguin? they are all flightless but winged to an extent), or have a head but "no neck" and also have a phyrynx growing from its torso (a velvet worm doesn't have a torso, right? and where do the head attach to the body?) | |
| Apr 1, 2021 at 21:30 | comment | added | DKNguyen | Difficult to say...as far as I know, no lineage that has evolved a head has evolved away its head. They diverged from creatures without heads diverged long ago. The issue is that things don't evolve away just because they have no use. They evolve away because they are detrimental, and so EVERYTHING in the head as well as the head itself would have to be detrimental in some way. The head is part of the basic body plan and body plans tend not to change in large groups of animals, let alone just one animal. If there was one with such a drastic change in bodyplan, expect to see many others. | |
| Apr 1, 2021 at 21:09 | comment | added | Alexander | @Ichthys King half of its body then? | |
| Apr 1, 2021 at 21:09 | comment | added | Ichthys King | @chasly-supportsMonica There would be a constant selective pressure to shrink the head and push the brain back to protect it, unless there was some sort of feature that required a head with a brain to work optimally | |
| Apr 1, 2021 at 21:03 | comment | added | chasly - supports Monica | It would help if you drew a rough sketch of the creature. | |
| Apr 1, 2021 at 21:01 | comment | added | chasly - supports Monica | You said the brain is in the head. Isn't that a good enough reason to keep the head? | |
| Apr 1, 2021 at 20:56 | comment | added | Ichthys King | It can reach the ground with its pharynx, allowing it to eat while standing | |
| Apr 1, 2021 at 20:50 | comment | added | Alexander | How does it eat? Does it have to reposition its entire body to take bites? | |
| Apr 1, 2021 at 20:45 | history | asked | Ichthys King | CC BY-SA 4.0 |