How to make petroleum in Little Alchemy

To make petroleum in Little Alchemy you have to combine this elements:

1. fossil + pressure
2. fossil + time

Petroleum Step by Step

How do I combine the necessary elements to create petroleum in Little Alchemy?
Here we show you the walkthrough, just follow the steps below:

1 air + fire = energy

2 earth + water = mud

3 air + air = pressure

4 earth + fire = lava

5 air + water = rain

6 air + lava = stone

7 earth + rain = plant

8 air + stone = sand

9 fire + sand = glass

10 mud + plant = swamp

11 energy + swamp = life

12 air + life = bird

13 bird + bird = egg

14 glass + sand = time

15 egg + swamp = lizard

16 lizard + time = dinosaur

17 dinosaur + earth = fossil

18 fossil + pressure = petroleum

Below you can see a video tutorial on how to make petroleum in Little Alchemy:

Combinations with other elements are not yet known.