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