That's... huge? I don't really see the problem with that. This is from the veryearly Cambrian. The first thing we tentatively assign as an 'animal' (Caveasphaera) came less then 100 million years before it. It comes from the same million year period that featured the first known arthropod (Kylinxia) and absolutely dwarfed that creature. It's 6 times longer.

The size difference between this and what else was around seems pretty close to the difference between you and an elephant.