Answer:
Due to presence at early days of the planet.
Explanation:
We only find the remains of single celled organisms in the oldest fossils because the single celled organisms are the organisms that were present in the early days of this planet. These single celled microbes were present about 3.7 billion years ago while on the other hand, the oldest rocks are only a little older i. e. 3.8 billion years so these single celled organisms are considered as oldest fossils on this planet.
<span>Bivalvia - Clams, Oysters, Scallops and Mussels.
Cephalopod - Octopi, Squids, Cuttlefish, and the Chambered Nautilus.
Gastropoda - Snails and Slugs.
<span> Polyplacophora - Chitons.</span></span>
Is this a multiple choice question or...??
If not, I'd say, that its simple as scientists can easily decipher which variable caused the situations result. And thats because you may have one manipulated variable to be able to know the responding variable.
Albert Einstein is an inventor and scientist, he was one of the main reasons the us is the us right now. Hope this helped!
