Despite what the mission encourages, I found that there was actually very little need for static defenses, opting instead for a ball of zerglings and mutalisks.
If you're not already using it, consider using Zergling Reconstitution for this mission, and try to build up 20-30 'lings (Raptors are preferable, if you're playing from the master archives) and then just start massing mutalisks.
The goal here is for your zerglings to "tank" the primal zerg, in that they delay them from reaching the Chrysalisuntil your mutas can reach the intruders and annihilate them with bounce attacks.
Building a large force of mutas also allows you to take out the Tyrannozor pretty easily - simply fly over the battling primals, and burn him down with your air units. Unlike most missions, you do not actually need a ground unit to collect the essence it leaves behind, so there's no reason to use ground units at all.
As the mission progresses, especially in the last 6 minutes, the primal zerg will stop coming in waves, and start coming in a constant stream. Make sure that before you reach this point you build 5-6 swarm hosts and root them around the Chrysalis. Between the swarm hosts themselves and the locusts they spawn, they'll form a solid "Wall" around Kerrigan that will prevent the primal ultralisks, roaches, and zerglings from melee-ing the Chrysalis. (Unlike the other units, since they can't attack air, they won't be distracted by your mutas, until they die). You can't build crawlers directly in the pool to wall off that way, but your ground units can burrow (or root!) in it just fine.
And finally, be sure to use the Locust ability of the Chrysalis as needed -- there is nothing to be earned from not using it, so use it as-needed.
One final thing to consider is that, should you find the Chrysalis has taken a lot of damage in a previous attack, you can use the abilities of your Swarm Queens to heal it.