The dominant organisms during the Precambrian include the proarticulatans, such as Dickinsonia, Yorgia, and Praecambridium which were a group of "air-mattress" organisms possibly related to modern day placozoans, rangeomorphs, such as Rangea, and Charnia, which were frond-shaped organisms that had bilateral to radial symmetries, and the trilobozoans, like Tribrachidium, which were disk-like organisms with a tri-radial symmetry, possibly related to cnidarians.
The ancestral mollusk, Kimberellia, is found throughout Precambrian strata of the world.
There were also sponges, and what have been interpreted as the polyps and medusae of cnidarians during the Precambrian, as well. Very primitive worms and arthropods appear at the very end of the Precambrian, as it transitions into the Cambrian period.
Life had only just started during the precambrian. Most life during the precambrian consisted of nonanimalian protists and bacteria. Maybe by the very very end of the precambrian there were the first jellyfish and worms. The precambrian started 4.6 billion years ago. Life started and consisted of bacteria 3.8 billion years ago. The precambrian ended about 590 million years ago.
Oxygen
Most rocks from that era are deeply buried.
Archeozoic and ProterozoicThe two periods of the Cenozoic Era are the Tertiary and the Quatemary.
It is best to break down the question into smaller parts.1) The Precambrian was the 1st Era? (FALSE)The Precambrian was a super-eon not an era. It was the 1st of the 2 Super-Eons.The 1st named era was the Eoarchean Era (3,800 - 3600 Ma). This was during the Archean Eon (3,800 - 2,500 Ma). This was proceeded by the Hadean Eon (4,600 - 3,800) but no Eras from this time have been named. These were all in the Precambrian Super-Eon (4,600 - 542 Ma).2) The Precambrian was the longest Era? (FALSE)The longest era also occurred in the Precambrian. This was the Paleoproterozoic Era (2,500 - 1,600 Ma) which lasted 900 million years.3) The Precambrian lasted 4 billion years (TRUE)The Precambrian was the longer of the 2 super-eons. It lasted from 4,500 to 542 million years ago, some 3.96 billion years, compared to the current super-eon that has lasted a mere 542 million years.4) During the Precambrian the Earth had no solid crust (FALSE)The Earth is approximately 4,600 million years old. According to the latest theory 4,530 a Mars sized planet called theia hit the earth causing the crust to in part or totally melt (It also gave rise to the moon). Estimates suggest that over the next 30 million years the crust was able to solidify so when the Precambrian Super-Eon started the crust was solid. Certainly by 3,500 million years ago there was life. Fossilized stromatolites have been found at this time. There is no known life that can survive at the temperates necessary for molten rock so the crust must have cooled and solidified by this time.
The Precambrian Era. The name means: "before the Cambrian period." This old, but still common term was originally used to refer to the whole period of earth's history before the formation of the oldest rocks with recognizable fossils in them. In the last few decades, however, geologists have found that there are some hard-to-discern fossils in some Precambrian rocks, so this period is now also known as the Cryptozoic or "obscure life" Eon (from the words "crypt" = "hidden," and "zoon" = "life"). The Precambrian covers almost 90% of the entire history of the Earth. It has been divided into three eras: the Hadean, the Archean and the Proterozoic. Source: Unknown The Precambrian Era comprises all of geologic time prior to 600 million years ago. The Precambrian was originally defined as the era that predated the emergence of life in the Cambrian Period. It is now known, however, that life on Earth began by the early Archean and that fossilized organisms became more and more abundant throughout Precambrian time. The two major subdivisions of the last part of the Precambrian are the Archean (oldest) and the Proterozoic. Rocks younger than 600 Ma are considered part of the Phanerozoic.
Jellyfish intervirbrates
Precambrian
Precambrian
The animals in the Precambrian Period were soft bodied animals. This Era was dominated by single celled organisms: algae, bacteria. Also in existence were jellyfish, spiders, crabs, and worms.
Animals without backbones, called invertebrates, developed near the end of the Precambrian. Imprints of jellyfish and marine worms have been found in late Precambrian rocks. Because invertebrates were soft, they weren't easily preserved as fossils. This is one of the reasons why the Precambrian fossil record is so sparse.
single-celled organisms and soft, boneless animals
Ferns
Yes. The first era was the precambrian era followed by the paleozoic era then the mesozoic era than the Cenozoic era.
**Precambrian**
the Precambrian era
As far as we know for the majority of the Precambrian super-eon the only life on earth was bacteria.At the very end of the Precambrian multicelled life evolved. Amonst them jellyfish, invertibrates, sponges and pretty much a prehistoric version of most sealife today. There is also very suggestive evidence for simple plant life in the form of green algae in the Precambrian.
it was on earth the precambrian era is an era that happend several million years ago on the earths surface