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