Here is the full list of all 29 Second Extinction achievements.
Kill 6666 Enemies.
Deploy 100 times.
Complete 40 Contracts.
Respawn 100 times.
Respawn 40 times.
Kill a T-Rex with a Supply Drop.
Unlock all perks for one weapon.
Kill 2000 Enemies.
Complete 20 Contracts.
Complete 10 Contracts.
Respawn 20 times.
Play 20 missions at night.
Deploy 50 times.
Deploy 20 times.
Kill 750 Enemies.
Deploy 10 times.
Complete the mission "Contact".
Complete all core missions.
Complete the mission "Homebound".
Kill 20 Enemies with Supply Drops.
Complete the mission "Charged Extraction".
Complete the mission "Vestige".
Find the golden egg.
Complete the mission ”Research And Rescue".
Complete a mission without using a Health Stim.
Complete the mission ”Black Site".
Complete a mission without any on the team having to respawn.
Take a raptor with you when you extract.
First Deployment.