Here is the full list of all 47 Fossil Hunters achievements.
Collect all other achievements
Complete all the Collector's requests
Make 100 skeletons
Submit a skeleton with every piece damaged
Pick up an idol from the treasure hoard
Finish the game
Collect all Abyss journal entries
Collect all journal entries
Unlock all schematic doors
Submit 50 clean & pristine skeletons
Drop a golden idol in a pit
Collect all golden idols
Build 5 colossal skeletons
Make 50 skeletons
Die in a pit 100 times
Use 20 supports
Use 20 bridges
Build 10 huge skeletons
Prevent a death with a dodge roll
Collect all Magma Chamber journal entries
Use 20 lamps
Unlock the dynamite shopkeep
Pick up the Sammy rock and bring it to the elevator
Unlock the bridge shopkeep
Get all destruction achievements
Have a fossil smashed by a lavamander
Have your multiplayer friends drop out
Play as each of the Fossil Hunters
Build 15 big skeletons
Collect all Mushroom Caverns journal entries
Have all three power-ups active at once
Drop 50 fossils in pits
Collect all Digsite journal entries
Use 20 dynamite barrels
Transport 12 or more items with the elevator
Rearrange the furniture in the lab
Unlock the support shopkeep
Make 10 skeletons
Have a fossil covered in moss
Unlock the lamp shopkeep
Collect a golden idol
Have a fossil eaten by a crawler
Unlock a schematic door
Have a fossil smashed by a cave-in
Leap the maximum distance
Make a skeleton
Bring 20 new objects into the lab