# With dunkle-like Jaws, how long could the neck be?

The Apex predator of the Sea of Grass biome from planet Andromeda is mostly bipedal, but capable of facultative quadrupedalism, it has long limbs, powerful claws on its hands and is roughly the size of an utahraptor, but with a neck that can be from twice to thrice as long. It is a pursuit predator, running after its prey (which usually has similar size or is slightly larger) on all fours until it is close enough to it. It will then hold it with its forelimbs while using its Jaws to slice chunks of meat off until it can no longer run away. It's neck is usually very close to the body, like a green heron's, extending only once it has a hold of it's prey, in order to bite at more strategic places. It's Jaws, on the other hand, are toothless, being composed of bladed, self-sharpening plates much like those of the dunkleosteus, which are meant for cutting pieces of swallowable size.

Now, could such Jaws be used alongside a long neck? I feel like it would need strong muscles to hold the head like terrorbirds did, but I'm not sure if such fearsome Jaws would truly work well with an "extendable" neck. It's cranium has a crest on its back, serving as an anchor point for muscles while Making its head similar to a long snouted dunkle.

image source

NOTES-It's planet has earth like conditions, safe for a slightly denser atmosphere, and it's main habitat is composed of plains much like the African Savanah, except for larger, yet more separated trees. Prey is composed of creatures much alike earth's ungulates.

• It's Jaws, ... are toothless, being composed of bladed, self-sharpening plates Ummm... so, claws for anchoring the prey, and smooth scissor-jaws to cut through its skin and flesh? Try an experiment - take a newspaper and make a thick and tight roll from it. Then take a pair of scissors and try to 'mortally wound it', like getting deep enough to severe an artery one inch under the skin. (my point: your blades will need to be pointy in front to puncture first, chop after). PS: apologies for the pointless pun – Adrian Colomitchi Mar 26 '20 at 2:08
• Source for good Dunk gif please? I was just reading about how it could pull its head back to gape for that other question. And this shows it! – Willk Mar 26 '20 at 2:18
• @Adrian Colomitchi I am aware of that, which is why I also based on the Dunkle's jaw power, akin to a that of the T-rex, but with an greater amount of pressure due to the sharp blades. Think of it as getting the same roll of journal and instead using a hydraulic paper cutter to wound it – ProjectApex Mar 26 '20 at 4:05
• @Willk here's the site where I found it: tumblr-amnh-org.cdn.ampproject.org/c/s/tumblr.amnh.org/post/… but would you mind telling me what other question? – ProjectApex Mar 26 '20 at 4:10
• Upvote now that link is here! Other question: worldbuilding.stackexchange.com/questions/171931/… – Willk Mar 26 '20 at 12:22

You can, but it has other bigger problems, but maybe fixable ones.

You can make the neck as long as you want, but be aware the longer you make the neck the weaker it becomes, so if you make it too long they can't use any force from the neck to assist in biting and tearing which makes it pretty poor for attacking large prey. The design itself is really not that different than any beaked predator, most predators that attack with the head swing the skull up and back as part of the bite, vertebrates just have the pivots at the spine. The shape of the "beak" is what determines how effective it is for hunting, and beaks are horrible for taking a "bite "out of prey beaked predators rely on tearing or being much larger than their prey, and that is the type of "beak" dunkleosteus has, those tall pointed blades in the front work the the fangs of toothed predators or the hooked beaks of birds of prey, they pierce and give anchorage for tearing off pieces of flesh, they will not be good at slicing.

You need a sharp serrated surface to cut a chunk of flesh out, although even then it is slow and requires a lot of sawing motion. So modify the shape of the "beak" and don't make the neck too long and you are plausible. The green herons neck is probably too long, I would says restrict yourself to about 2/3rd that length but it is not unbelievable.

Otherwise leave the beak the way it is and put a shorter stronger neck on it to tear with.

• I have some issues regarding your argument towards the effectiveness of this plated arrangement, as it's already been proven to be quite effective both at slicing flesh and for cracking some hard surfaces (so long as backed with the necessary strength, naturally, but that is already granted here), which allowed the real deal to slice fish and other creatures in half. But your detailing on the neck structure was very helpful, thank you very much. – ProjectApex May 18 '20 at 20:11
• @ProjectApex as I said those rely on cutting things much smaller than the predator, it works through sheer force. It is the same reason a snapping turtle can bite a finger or fishing clean though but would be hard pressed to take a chunk of flesh fro the side of a mammal of similar mass to itself. It is why a pair of scissors can cut thin wire but would not even dent thick rope. You are asking specifically about attacking animals of similar or greater size. keep in mind dunkleosteus is a massive predator. – John May 18 '20 at 20:22
• I see, though it's been shown they could predate on creatures roughly their size, I'll keep that in mind. Thank you very much for the insightful answer and heads-up on how my predator might use it's "tools" more effectively. – ProjectApex May 18 '20 at 20:37
• Keep in mind one thing we see with dunkleosteus is the larger they get the more fang like the front blades are, puncturing becomes more important. and feeding in water is diffrent than feeding on land, the water provides enough resistance that you can shake your body to provide the tearing force. – John May 18 '20 at 20:41

If the head has the full set of bones that a Dunkleosteus had, then there isn't any reason why the jaw system must be attached directly to the torso

Practically, not long at all

Theoretically, the neck could be pretty long, as there's no biological reason why you can extend a neck out far, even with the Dunkleosteus's unique jaw mechanics. Practically, you don't want to extend it at all. Take another look at the way the jaw functions - it needs those back set of plates (the thoracic shield) in order for the jaw to function properly which means that the head is going to be set inside of a neck larger than it. Not such a problem for the Dunkleosteus, which is a fish, and thus doesn't really have a neck - the head is sunken into the main body. Given that a neck larger than a head is impractical (read: the neck is a massive vulnerability on any living creature which is why it's usually protected as well as possible) and this means that, from an evolutionary standpoint, your creature really wouldn't have a neck to begin with,