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