On single player, it will definitely be a bit harder since you won’t have other “meat bags” to sacrifice. The best way I find to knock this Dino out is if you don’t have the tranquilizer engram, you use your highest ranged weapon (most likely the ascendant bow you’ll get from the Hunt Dilophosaur pursuit) that uses tranq arrows. Practice shooting if you want, but the spino has a large hit box because the fan on its back also counts as a part of it. Check Dododex on the possible level of the Spino you want to tame. Sometimes, you may want extra ammo to knock it down guaranteed. Finally, knock it down and make sure you have anything to increase its torpor by a lot. It’s not as bad as the Therizino from experience, but its torpor drains quickly so be sure to check it constantly. If you want a safety net when engaging. Mount on a tanky mount and make sure you can still shoot. That MAY only harm the Dino, which benefits from the armor by the saddle, depending on size. Good luck with taming.