Coral Island

In order to complete this you must find and donate to the museum 60 unique fossils. Fossils come from Fossil nodes.

Before Fossil nodes will drop you must expand the Museum and acquire the special item: Soft Bristle Brush (Unlocks the ability to recover fossils and torn pages)

The requirements for this are to donate any 50 items to the museum and wait until Scott's pickstarter campaign finishes and the museum expansion Cut scene plays out.

Fossil nodes are rare drops when destroying stone with your pickaxe or trash with your scythe. High concentrations of stone are in the Earth, Water, Wind, and Fire caverns and high concentration of trash is in the ocean and ocean caves.

The game on Xbox or Game Pass PC does not currently give unique names to the 5 different fossil nodes. However, it seems the community named them as follows:

Mysterious (trash): Contains all small and medium fossils
Small (rocks): 18 Fossils (Mammoth, Pterodactyl, Velociraptor)
Medium (Medium or Large rocks): 18 Fossils (Gallimimus, Stegosaurus, Triceratops)
Large(Yellow) (Large rocks): 12 Fossils (Brontosaurus, Tyrannosaurus)
Water: (trash): 12 Fossils (Mosasaurus, Plesiosaurus)

48 fossils can be obtained in the ocean. The 12 from Large(Yellow) fossil nodes from the caverns or other large rock sources like the Dig Site.

Once you have a fossil node you take it to the Reasearch Lab and pay 20coins to process each node. The drops from the fossil nodes are random and can contain a fossil or ore or other materials.

Once you donate the 60th unique fossil to the museum the achievement will pop, and you will be rewarded with the Dino Suit.


Tips
Fossil Node Drops are determined per node at the time of processing. This means you can stock up some fossil nodes and head to the research center and if you do not get any new fossils or the last one you are looking for you can reload the day and go try again and will get different results.

In order to give you more real time each in game day to clear stone or trash go into settings on the Game tab and change Game Time Speed to 50% which will slow in game time down to half giving you twice the amount of real time to play each in game day.

Farming for the majority of your fossil nodes (48) is best done in the ocean and ocean caves. There is a higher concentration of trash then stone and the drop rate is a lot higher from trash than stone.

You will need to farm the caverns for Large (Yellow) Fossil nodes.

Due to the nature of the swinging arc of the scythe you can hit 3+ nodes of trash at a time consuming a lot less energy and time to get drops compared to a pickaxe and stone. Furthermore, the ocean caves are endlessly filled to the brim with trash and opening the next room happens after you clear a certain percentage of trash not a specific node of it like the caverns.

Enchanting your pickaxe and scythe at Giant Village with: No Energy Drain which at tier 4 gives you 40% chance not to consume energy on hit. Rare Drop % and Extra Drop % is advised.

I use No Energy Drain on Copper and add Rare Drop on Silver/Gold then add Extra drop once I upgrade them to Osmium.

Equipping the 'ring of speed' which increases tool speed use is very noticeable especially when using your pickaxe.
Equipping the 'blessed opal ring' which increases the chance to find rare items also helps.
- Note: I tested wearing two of these and while it may have slightly increased drop rates the loss of tool speed was painful and not worth the effort.
Both of these rings will come from chests in the caverns as you progress through them.

I used the wiki which is nicely organized the same as the journal here: https://coralisland.fandom.com/wiki/Fossil?so=search#Journal... Much easier to cross reference what I'm missing to know which fossil types I need to gather.