A taxonomic riddle game

I discovered the game metazooa.com:

That’s exactly the type of gameplay you want to test your knowledge of animal phylogenetic classification (systematics).

There is a mystery animal everyday, you have 20 tries. Each time you are wrong, it tells you what is the most recent common ancestor between your try and the mystery animal.

I like it, but I think it has defaults, some of which being design choices:

• the number of selected species is too small (or it should be customizable, I want a hardcore mode);
• as the author states, the selection is “based on how familiar they are to people”. That’s unfortunate, because it would have been the occasion to actually show people that what they are familiar to is a biased representation. In fact, the game is really biased for vertebrates, especially mammals. Secondly, the author seems american, so some species choices are american (for instance, there is the blue jay species, but not the european one. or the bald eagle. etc.). Of course, we can’t include all insects, but a bit more is required. and there is no tardigrade 🤓…
• The bird phylogeny is really unresolved, I would try to add intermediate nodes.

Some representatives of interesting lineages I would add again:

• panarthropods
  • tardigrades
  • velvet worms
  • sea spiders (pycnogonids)
• flatworms (e.g. fluke), roundworms (taenia, Caenorhabditis)
• teleost fishes
  • sturgeon
  • arapaima
  • bowfish
  • spotted gar
• sponges
• (more) echinoderms
• shrews

Some lineages I would expand to more than one species:

• jellyfish
• coral

Some animals I tried but were not included:

• monkfish
• sunfish
• grouper
• mackerel, herring, sardine…
• stickleback
• tit
• stork