Sponges are outliers in biology’s big bang, the Cambrian explosion. Their embryos appear in Precambrian strata, leading some to consider them primitive.
The highly valued optical properties of pearls come from sophisticated processes of biomineralization involving proteins and crystals.
Last but not least, there is this gem: In 1986 strange mushroom-shaped deep-sea animals were collected offshore South Australia.
Evolutionists would expect to find sponges as the earliest animals in the fossil record.