When finishing a element vein on extincion make sure to easily harvest the normal spreads with Yutyrannus buff. For the main one hit the elementvein till it has about 1.6hp left. At the end use the jump attack and harvest it. You will get so much element.
The most versatile of Scorched Earths creatures. A Mantis can hold the roles of multiple different creatures depending on the tools or weapons it has equipped. Picks and Hatchets make them ultimate harvesters, Pikes and Swords can turn them into deadly combat mounts and Clubs can allow them to quickly down creatures for taming, they have no need for Sickles since they can harvest fiber by default. However you'll need to level it's stats depending on the role you plan to assign it to. For example, if you want too make a Mantis a harvester weight and Melee are what you'll want to go for, if you want it to be a expert at combat health and Melee with some stamina in case things go wrong and you have to flee are the way to go since there pounce attack is enough to quickly cover ground and escape a aggressor, and KO'ers really need nothing more then health in case the target is something strong that fights back and some Melee to increase the amount of torpor inflicted by the clubs
Mantises are really useful. They are hard to tame, but once you did, you will not regret it. They are great at harvesting fiber, and kill creatures quickly. They are also great at harvesting meat and hide.