Short answers, pulled from the story.
The first crustacean to be named in scientific history was a tiny, shrimp-like creature discovered in the Cambrian period. This discovery marked the beginning of a lineage that would eventually dominate the oceans.
The subphylum Crustacea includes over 67,000 described species. Scientists believe the actual number could be much higher, with many species yet to be discovered.
The earliest and most characteristic larval form is the nauplius, which has three pairs of appendages emerging from its head and a single naupliar eye. This stage is found in many groups of crustaceans, including copepods and branchiopods.
Recent studies suggest that insects are more closely related to crustaceans than to other insects. Modern phylogenetic studies have revealed that hexapods, including insects, are nested within a larger Pancrustacea clade.
Krill are the bottom layer and most important part of the food chain in Antarctic animal communities. They support a wide range of predators, from whales to penguins.