Dauntless puts you on a gear treadmill that constantly has you seeking out new Behemoths to kill. Among the many reagents you'll have to sort through, you'll also find the sparkspine.
Here's everything you need to know about how to get the sparkspine reagent in Dauntless and upgrade or craft yourself some new gear.
In order to get yourself one sparkspine or more, you'll have to go out there and face the Nayzaga Behemoth found in The Uncharted Reaches.
You'll have to prioritize attacking the Nayzaga's tail for a chance at getting the sparkspine reagent. Luckily, it's one of Dauntless' common drops, so it likely won't take all that long to get yourself some.
The Nayzaga is attuned to the shock element, so wearing shock resistant armor and bringing a weapon imbued with the terra element is recommended when hunting for shockspines in Dauntless.