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