Step 1: first you have to kill a male rhyniognatha and take the pheromone from its inventory

Step 2:take a Dino which can eat the pheromone I recommend taking a brontosaurus, rex ,yutyrannus and trike

Step3: find a low lvl female rhyniognatha (you can use high lvls also but they do more dmg)

Step 4: drop the female to below or 100 health (when you think you can 1 shot it use tranq arrows or a spear or pike) quickly feed ur Dino the pheromone before the rhyniognatha flees away

Step 5:your Dino will be impregnated and it will crave 5 different foods

(It's health will go down but don't try to heal it it's a waste of time and food) the time for the baby to come out will be 1 hour and feeding the 5 different foods is not compulsory but it will highly effect the lvl

Step 6: you now have a juvenile/baby rhyniognatha!!!!!

Best strategy from what I’ve found

1 first scout the swamp with a spyglass from the back of an argy. This will allow you to see the gender without getting too close.

2) If the bug is a male, kill it and harvest pheromones. If female make a note of location for later. For killing the male use beelzebufo or Megatherium.

3) feed pheromones to a tame with high drag weight. My personal recommendation is Paraceratherium as they are very common and fairly easy to replace. Also the platform saddle plus mini gun turret makes it simple to get a female to ten health

4) track down female and get it to 10% health. If you find yourself with multiple pheromones and multiple sacrifices you can get multiple tames implanted with eggs in one fell swoop.

5) meet creatures very bizarre food demands until baby makes its big entrance and ta da. You now have a giant incectoid assault chopper.

Now that they've come out I've tested them a few times to try and see how they're tamed.

You wanna grab a tame (I used gigas), preferably with good stats and/or one you don't mind losing - and bring it to wherever they spawn on the map you're using. You should go off and kill a Rhynio (any gender) on your own first, or with said tame so that you can harvest a pheromone from its corpse. Once you have that pheromone, feed it to the tame and then go and find another Rhynio (I believe only females can infest your tames, correct me if I'm wrong!) And aggro it to your tame while the pheromone is affecting it. Keep your tame on passive and let the Rhynio do it's thing! You'll have to shoot the Rhynio while it attacks your Dino, and get it below and certain threshold of health. It'll then perform an animation as if it is about to spit resin, but will do some sort of dive/corkscrew into the tame and voila! Your tame is now infested. Your tame will receive strange cravings while it incubates the baby Rhynio, and they're strange. It can be stuff like element it wants, ranging from consumables like battle tartare to even ammonite bile and achatina paste, all kinds strange things. Once the incubation timer goes down, your tame will die and out will hatch a juvy Rhynio! They won't aggro onto you when you hatch them (at least not in my experience) so super easy to just run up and claim them!

You also can't breed them, I don't think. Doesn't let me anyway, which isn't fun.

I found a high level Yutyrannus, and tamed him. After that I turned Dino damage to 0 Dino resistance to zero (Ark ultimate mobile edition) and tryed to get him to my base (along with my newly tamed direwolf and not new argy) that happened to be on the island on the opposite side of the swamp. These could not damage it with melee, but 6 shot it with resin. I backed out of the game immediately and then killed the one I knew where it was at by jumping off my argentavis and shotgunning it (after I turned resistance to back to normal. Then I set the settings back to the original and 3 more came. Basically same solution, but please fix the rhynogantha from doing resin damage/kills when Dino damage is at 0.0 and stop them from spawning so much, it makes the game miserable.

Unfortunately, as of today’s date (April 4, 2025), on Ultimate Mobile Edition Rhynios are affected by a very pesky glitch: they refuse to follow you! That means when you’re raising one, just hope that they do not request to walk for imprint, because they will not move.

I discovered this the hard way when raising a low-level one that I call Boneglue— who earned his name because he would not move and it was like his bones were glued in place, and also because I was tempted more than once to turn him into cementing paste glue. (Not a terrible idea if you’re low on that stuff. Rhynios are surprisingly easy to obtain.)

Ok. One of these things killed my argy level 100 with 3000 health and she died so fast. So I came back to the swamp on Big Bill. My level 97 spino. I quickly got the pheromone then I went home got on Titan my bronto Bill followed us we sat at a red wood edge. We accidently killed the level 25 female but a level five impregnated Titan. I couldn't get any cravings the baby was born I named him Titan after his mom. And after giving him a saddle I killed 6 trikes before he was even level 10. TAME THESE BUGS