Fossils and Fossil Pets

Overview

The BONEYARD is the third tab of Expeditions. Crews sometimes come home with a Strange Slab and, far more rarely, with a fossil. A slab is one go at the Fossil Excavator, a chisel-and-rock digging game that hides bars, bone dust, pet items and — in about one slab in 10 — the buried shape of a fossil. Uncover that shape whole and you learn the fossil's forge recipe for good. With the recipe, a fossil and bars, the Fossil Forge revives a fossil pet: 6 pets that exist nowhere else in the game.

So a fossil pet takes two separate pieces of luck: the fossil item (from long expeditions in its world) and its recipe (from digging slabs).

Finding slabs and fossils

Both are rolled only when a trip finishes (never on a recall), per hour underground: 1.2% an hour for a Strange Slab and 0.6% an hour for a fossil. A fossil is always one of the fossils of the mine's own world, so the World 5 fossil only comes out of World 5 mines.

What raises them: the Paleontologist's Brush on any crew member (slabs), the SLAB and FOSSIL rows in the world upgrade shops and The Armory, the FOSSIL HOUND dust perk (both), and the fossil pet Cinderhatch in the crew. Neither is capped: past 100% every whole 100% is a guaranteed find and the rest is a chance at one more (a 212% chance is 2 slabs and a 12% shot at a third). You can also buy slabs outright for 150 bone dust each.

The dig

Spending a slab lays a bed of 9 × 6 = 54 tiles of rock and hands you a chisel with 16 charges. Every tile you chip open costs one charge, and no tile tells you anything about its neighbours. When the charges run out the dig ends and everything you uncovered is yours.

• Bars — only bars from mines you have open, each treasure worth about 1.5–3 hours of one cart of your best crew.
• Bone dust — the Boneyard's currency.
• Pet items — now and then.
• A fossil — 10% of slabs hold one. It covers 8 to 16 tiles, can be turned or flipped any way, and can lie anywhere in the bed. All 6 fossils are different sizes, so the share of the fossil a single bone tile reveals tells you which one you have hit — but a fossil's shape stays hidden in the guide until you have learned it.

Uncover a fossil completely and its forge recipe is learned permanently. Leave it part-dug and it crumbles into 3 dust per bone tile you did open. Once a recipe is known, fully uncovering that fossil again pays 6 dust a tile instead.

Which fossil a slab holds is weighted by world, among the worlds you own — earlier worlds are commoner:

	Fossil	World	Weight	Chance per slab (all worlds owned)
	Great Claw Fossil	World 1	100	2.63% (1 in 38)
	Feather Imprint	World 1	100	2.63% (1 in 38)
	Frozen Tusk	World 2	70	1.84% (1 in 54.3)
	Horned Skull	World 3	50	1.32% (1 in 76)
	Spiral Shell Fossil	World 4	35	0.921% (1 in 109)
	Petrified Egg	World 5	25	0.658% (1 in 152)

Bone dust and perks

Bone dust buys three things: more slabs (150 each), extra forge slots (3,000 then 12,000 dust — you start with one and can own 3), and dust perks. Perks sit in four tiers; a tier opens once you own enough perk levels in total: Tier 1 at 0, Tier 2 at 10, Tier 3 at 30, Tier 4 at 50. Maxing every perk costs about 23,780 dust.

The 15 dust perks

	Perk	Tier	Works in	Per level	Levels	At max	First level	Dust to max
	Longer Chisel	Tier 1	DIG	+1 chisel charges on every dig	14	+14 chisel charges on every dig	20	1,190
	Spare Chisel	Tier 1	DIG	5% chance a dig starts with one extra charge	8	40% chance a dig starts with one extra charge	20	475
	Glinting Eye	Tier 1	DIG	5% chance a treasure glints through the rock when a dig starts	8	40% chance a treasure glints through the rock when a dig starts	20	475
	Dust Sifter	Tier 1	DIG	+5% bone dust from every dig	8	+40% bone dust from every dig	20	475
	Rich Seam	Tier 2	DIG	5% chance a slab holds one more treasure	8	40% chance a slab holds one more treasure	40	960
	Fine Finds	Tier 2	DIG	+5% bars in dig treasures	8	+40% bars in dig treasures	40	960
	Fossil Hound	Tier 2	EXPEDITIONS	+4% Strange Slab and fossil finds	8	+32% Strange Slab and fossil finds	50	1,195
	Petrified Fortune	Tier 2	BOARD	+0.5% board coins	8	+4% board coins	60	1,430
	Bone Sense	Tier 3	DIG	5% chance a fossil in the slab shows one bone when the dig starts	6	30% chance a fossil in the slab shows one bone when the dig starts	140	2,025
	Steady Hands	Tier 3	DIG	3% chance chipping empty rock costs no charge	6	18% chance chipping empty rock costs no charge	140	2,025
	Warm Forge	Tier 3	FORGE	-5% fossil forging time	6	-30% fossil forging time	105	1,515
	Sabre Grip	Tier 3	HOARD	+0.5% hoard chest damage	6	+3% hoard chest damage	140	2,025
	Second Slab	Tier 4	DIG	3% chance a dig hands its slab back	5	15% chance a dig hands its slab back	275	3,010
	Amber Pick	Tier 4	BOARD	+2 lock damage	5	+10 lock damage	275	3,010
	Trophy Bones	Tier 4	HOARD	+4% hoard chest shards	5	+20% hoard chest shards	275	3,010

The Fossil Forge

The Fossil Forge takes three things: the fossil item, its learned recipe, and bars from the fossil's world. It costs no coins. Forging takes real time (the WARM FORGE perk shortens it) and each forge slot works one fossil at a time. When it is done you claim the pet: a Lv 1, 1★ regular pet that can be traded like any other.

Forge recipes

	Fossil	World	Revives	Rarity	Forging time	Bars
	Great Claw Fossil	World 1	Gravelclaw	UNCOMMON	2d	180K Tin Bar 113K Silver Bar 54K Verdite Bar
	Feather Imprint	World 1	Dawnwing	RARE	3d	270K Tin Bar 171K Silver Bar 81K Verdite Bar
	Frozen Tusk	World 2	Frostusk	EPIC	4d	462K Frostite Bar 297K Snowsilver Bar 145K Auroranium Bar
	Horned Skull	World 3	Trihorn	LEGENDARY	7d	2.52M Stonebark Bar 1.58M Bloomsilver Bar 798K Sylvanite Bar
	Spiral Shell Fossil	World 4	Coilshell	RARE	4d	6.4M Brinium Bar 4M Pearlsilver Bar 2M Kelpsteel Bar
	Petrified Egg	World 5	Cinderhatch	LEGENDARY	7d	14M Ashiron Bar 9.1M Smokesilver Bar 4.48M Venomite Bar

You can forge the same fossil as many times as you find it, which is how fossil pets earn their fusion stars.

The fossil pets

Fossil pets are regular pets with no pet crate odds at all — the forge is the only source. They level to 100 and fuse to 3★ like any regular pet, but they have no evolution (only World 1's crate pets and the Doppelgeist evolve), carry a nature, and sit last in the Pet Dex. Each one has one job with three abilities, and no two fossil pets share a stat. Ability N needs N stars, and like every pet's percent abilities they start at zero at Lv 1 and grow with level. Their abilities do nothing on the board: they work while the pet is in the crew of an expedition (or, for Gravelclaw, standing in the Hoard, and for Frostusk, working a Ball Factory machine), and crew-wide abilities from several fossil pets add together.

Gravelclaw

UNCOMMON THE HOARD World 1
A raptor with digging claws - it tears through the hoard
Revived from the Great Claw Fossil. Full pet page

Star	Ability	What it does	Lv 1	Lv 50	Lv 100
★	Raptor Rush	In the hoard, the whole crew deals this much more GATE damage.	+0.00%	+4.9%	+10%
★★	Pry Claws	In the hoard, the crew deals this much more damage to chests.	+0.00%	+4.9%	+10%
★★★	Gate Rake	In the hoard, the crew deals this much more damage to gates.	+0.00%	+4.9%	+10%

Dawnwing

RARE HOME SOONER World 1
An ancient sky glider - it flies its crew home early
Revived from the Feather Imprint. Full pet page

Star	Ability	What it does	Lv 1	Lv 50	Lv 100
★	Swift Wings	On an expedition, its crew travels this much faster (it adds to trip speed).	+0.00%	+4.9%	+10%
★★	Homing Call	Recalled early, its crew keeps this much more of the haul.	+0.00%	+20%	+40%
★★★	Tailwind	Every trip its crew takes comes home this many minutes sooner.	2	6	10

Frostusk

EPIC BALL FACTORY World 2
A mammoth thawed out to work the Ball Factory - tireless, and strong enough to carry the hopper
Revived from the Frozen Tusk. Full pet page

Star	Ability	What it does	Lv 1	Lv 50	Lv 100
★	Cold Forge	Working a Ball Factory machine, it forges this much faster.	+0.00%	+42%	+85%
★★	Tusk Rack	The machine it works holds this many more balls and bars.	+0.00%	+15%	+30%
★★★	Frost Sift	Its machine drops fuel and machine upgrades this much more often.	+0.00%	+9.9%	+20%

Trihorn

LEGENDARY MORE ORE World 3
Three horns that ram the ore loose from the rock
Revived from the Horned Skull. Full pet page

Star	Ability	What it does	Lv 1	Lv 50	Lv 100
★	Horn Charge	On an expedition, its crew brings home this much more ore.	+0.00%	+7.4%	+15%
★★	Boulder Bash	The chance a full trip of its crew also brings home a Hoard chest key.	+0.00%	+4.9%	+10%
★★★	Stampede	The chance a full trip of its crew brings home double the ore.	+0.00%	+2.5%	+5.0%

Coilshell

RARE RARER ORE World 4
An ammonite that sorts the rare ore from the rubble
Revived from the Spiral Shell Fossil. Full pet page

Star	Ability	What it does	Lv 1	Lv 50	Lv 100
★	Tidal Sort	On an expedition, the rarer ore of its mine comes up this much more.	+0.00%	+12%	+25%
★★	Pearl Pocket	On an expedition, its crew makes deep finds this much more often.	+0.00%	+7.4%	+15%
★★★	Abyss Dive	On an expedition, its crew's deep finds are this much bigger.	+0.00%	+20%	+40%

Cinderhatch

LEGENDARY RARE FINDS World 5
Hatched from a petrified egg - it sniffs out the rarest finds
Revived from the Petrified Egg. Full pet page

Star	Ability	What it does	Lv 1	Lv 50	Lv 100
★	Ember Eye	On an expedition, its crew finds pet items this much more often.	+0.00%	+20%	+40%
★★	Ash Sniff	On an expedition, its crew finds Strange Slabs this much more often.	+0.00%	+15%	+30%
★★★	Egg Sense	On an expedition, its crew finds fossils this much more often.	+0.00%	+15%	+30%

Tips

• Run 24 HR trips in the world whose fossil you want: fossils only drop from their own world's mines, at 14.4% (1 in 6.94) a trip before bonuses.
• Slabs are about twice as common as fossils, and only 10% of slabs hold a fossil — the recipe is usually the longer hunt. Put early dust into LONGER CHISEL.
• When the first bone shows, stop chipping at random: work out how the shape must lie and spend charges only on tiles it could cover.
• A Paleontologist's Brush works from any seat in the crew, so give it to a pet you always send.