Who is 'we' in your statement? Have you studied fossil jellyfish?
The particular fossils discussed in that news report are presented in more detail here:-
The authors describe the particular details visible in their specimens. They also are specific that the similarity is to orders and not specific modern species.
Remember that jellyfish constitute an entire phylum, on the same level as chordata. - all creatures with a notochord.
Alternatively, are you trying to define 'kind' as an entire phylum. That would certainly reduce crowding on Noah's ark.
We is anyone and everyone who studies these fossils using reason and logic... which usually excludes atheist/evolutionist worshippers. Now what I am saying is these fossilized jellyfish are the remains of the same species that we find today. I'm not speaking of just one species, but whatever species they might belong to. Some of these jellyfish may be extinct, but not all.
I believe kind is talking about species. Species are a group of animals that can breed, and produce fertile offspring. That's easy enough to tell in real life doing real breeding test... like what farmers do every year. Now, if your speaking of fossils... well, any extinct animal is going to be pure assumption based on what the fossil belongs to especially when it's extinct and unable to breed.