- Scientists have discovered the world's oldest known animal
fossils, dating to 650 million years ago. - The fossils, likely
sponges, push back the fossil record for animals by about 70
million years. - The sponges existed before, and probably after,
a severe "Snowball Earth" event that covered much of the globe
in ice. Animals have been on Earth for at least 650 million
years, suggest recently found primitive sponge fossils from
South Australia. This discovery pushes back the fossil record
for animals by about 70 million years, according to a new study
published in the journal Nature Geoscience. The prior oldest
known hard-bodied animals were reef-dwelling organisms called
Namacalathus, which date to approximately 550 million years ago.
Disputed remains for other possible soft-bodied animals date to
between 577 and 542 million years ago. The even more advanced
age of the newly found sponge fossils provides direct evidence
that animal life existed before the severe "Snowball Earth"
event. The episode marked t