Stromatolite:

Time: Precambrian 
Age: 542 Ma
Stromatolite is its first form of life on earth that is fossilized, it provides records of ancient life on earth. it still continues to form in certain areas even though it’s very rarely found.
It is created by photosynthetic Cyanobacteria.
Stromatolite is usually collected in the shark bay, Australia. 
They are typically in shallow waters, but can also be found in deep waters such as 45 meters below the ocean. 

Precambrian and Paleozoic era.

Collenia:

Time: Precambrian 
Age: 2.4 b.o
collenia was very common in the Precambrian era. These rocks hold the secrets to a time when land was once was covered in vast shallow sea, a billion years ago.
It is typically found in south central India located in the shallow, clear, quite waters. 

Elrathia Kingi:

Time: Precambrian 
Age: 515 ma.
E. kingi is one of the most common trilobite fossils in the USA. It has also been one the most recognizable trilobite. 
They are typically in shallow waters. They were living in low oxygen area which allowed these trilobites to easily fossilize. 

Heliolitida:

Time: Paleozoic 
Age: 455 ma.
heliolitidia is commonly known as tabulate corals and it is an extinct coral. They are almost all colonial.
This rock can be in many environments such as marine, reef, offshore and etc.
It is also found in North America, which was a low altitude continent at that time.   

Acaciella australica:

Time: Precambrian
Age: 800 ma
They are layered trace fossils of microbial life, primarily cyanobacteria. Some of them date back an astounding 3.4 billion years, making them the oldest record of life on planet Earth. They are mostly found in Australia by the reefs. 

Trilobite:

Time: Paleozoic
Time: 521 ma.
Trilobites are a group of extinct marine artiopodan arthropods that form the class Trilobite. Trilobites form one of the earliest-known groups of arthropods. 
They flourished throughout the lower Paleozoic before slipping into a long decline, when, during the Devonian, all trilobite orders except the Proetid died out. They are found in all modern continents. They feed through their glabella, which is an area of the cephalon which is usually more bulbous, is where the trilobite stomach is. 
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Gastropods: 

Time: Precambrian 
​Age: 541-585 ma.

Gastropods are normally known as snails and slugs. This class comprises snails and slugs from saltwater, freshwater, and even land. From lowlands to high mountains, they are found pretty much everywhere. There feeding evolved browsing and grazing through the algae rocks.