Fish is a paraphyletic grade that gave rise to tetrapods. Crustacean is a paraphyletic grade that gave rise to hexapods. These are analogous situations.
Yet inaturalist treats crustacean as an official group and not fish. Why? I cannot see any utility in keeping crustacea together that doesn’t apply to pisces as well.
Because Catalogue of Life is the taxon authority for animal subphyla and includes Crustacea but not Pisces.
It’s worth noting that from my understanding paraphyly of Crustacea is a much more recent discovery, with its wide acceptance probably post-dating the founding of iNat by several years. I also believe iNat staff have made it clear that shuffling very high level taxa around would be extremely disruptive and almost certainly never going to happen, so probably not the sort of thing worth dwelling on.
I believe the same happened with birds being dinosaurs being reptiles. While all three are listed as classes, all three are part of the reptiles. The same reason was given, however I don’t see why dinosaurs couldn’t at the very least be moved to the reptiles
@yongestation is correct. At this point, the iNaturalist database is so large it is virtually impossible to move around any high level taxa, sometimes even down to family. @loarie has said that they are looking into addressing this, but it will “not be addressed for a while.” iNaturalist is not intended to be a taxonomic authority, although unfortunately it is gradually becoming one simply by virtue of being the only platform that is kept up to date (on lower level taxonomy at least). Hopefully sometime in the glorious future we will be able to manage the higher level taxonomy again.
Some of that is discussed here: https://forum.inaturalist.org/t/list-of-paraphyletic-groups-in-inats-taxonomy/19456
This reminds me of my favorite podcast, No Such Thing As A Fish by the people that write for QI.
Honestly if they are gonna keep Reptilia and Crustacea they should have kept Pisces too.
why? if a new user wants to browse fish observations they can find 95% of them under Actinopterygii, which is the first thing that comes up if you type “fish” into the search bar.
i think it’d be nice if all the clades were monophylectic, but i do seriously see a downside in the new user experience if searching “reptile” fills with a page that is 90% birds and there is no easy way to just see traditional reptiles. and again, by the time the taxonomic status of crustacea was settled theres a good chance things were too entrenched here to change them.
IMO, given that genetic studies are showing phylogenies we previously could never have imagined (maybe we will eventually know if ctenophora or porifera are truly the most basal animals, and where placozoa go!) I think the ideal solution would be to have a truly monophylitic tree with support for paraphylitic groups. I don’t see any logical, scientific reason other than ‘this is how it’s always been and it’d be too hard to change it’ for why we should have dicots, crustaceans, or reptiles when we don’t have foxes or monkeys (and for that matter, tetrapods are in Sarcopterygii). I also hate pedants who say that chillas or grey foxes are not foxes because foxes are not monophyletic or that humans are fish. Humans are clearly not fish and that is not how we use language.
I made a Fish project which includes fishes and doesn’t include not-fishes: https://www.inaturalist.org/projects/these-are-fishes
I think Jason put it well. You might not agree with every word, but I think he makes a valid point:
(I bolded the punchline)
I strongly disagree with this “punchline”, especially the word “only”. I think in moderate doses having monophyletic groups which don’t match users preconceptions is a great way to make users more engaged with nature. When I learned cetaceans should really be considered ungulates, because they descend from hooved animals, I was not put off or frustrated, I instead thought this was very cool and wanted to learn more!
I think there is a balance to be struck here, I agree it may be very destructive and confusing to include birds under reptiles on iNaturalist but I think most of this so called “phylogenetic pedantry” presents a great way to get people more curious about the natural world.
Same thing for reptiles and squamates. I cannot think of any reason to remove Pisces but keep Reptilia. Either keep both or remove both
non-squamate reptiles make up a much higher proportion of reptile observations than non-ray finned fish vis a vis fish.
because not doing so would require a deviation from the taxon authority, and because searching “reptile” and getting a bunch of birds would be very confusing to new users. they had to draw the line in the sand somewhere, it’s fine if you’re upset with where it landed (i personally do wish we had purely monophyletic clades) but i think its disingenuous to act like these cases are perfectly analogous. are there any actual difficulties that the current taxonomy is causing you? if you want to search for fish, you can do so with the project here:
if you want to search for reptiles including birds you can do so here:
https://www.inaturalist.org/observations?subview=map&taxon_ids=26036,3
They are quite analogous. The equivalent of putting birds for reptilia is putting tetrapods under Pisces which we both agree is unhelpful.
Its not exactly an extremely dire issue, but I still haven’t found a real answer as to why reptilia was retained but Pisces was not.
I should have franed my comparison better. Squamata make up the vast majority of “reptiles” just as actinopterygii make up the vast majority of “fish”. So why not then dissolve reptilia and just have lepidosaurs, turtles and crocs as stand alone clades?
You say someone can find 95% of fish under actinopterygii, someone can also find 95% of reptiles under lepidosauria.
my understanding is iNat got their high level taxa from outside sources (WoRMS originally i think), and has always been resistant to being a taxonomic reference itself. are you then asking why WoRMS listed reptilia disjunctly from birds? probably mostly inertia, as this was eventually changed, but by that time the high level taxa had already been firmly entrenched in the system so they were forced to deviate and switched to CoL (see comments here: https://www.inaturalist.org/taxa/2-Chordata/taxonomy_details). at the time of iNat started a lot of these phylogenomic discoveries were quite new, and theres a tendency to be a bit conservative about massive changes to taxonomy and a desire to wait for consensus form. by the time this consensus did form, it was probably too late for iNat to switch.
only 80% of reptile observations are lepidosaurs. still a strong majority, but that’s four times as many omitted observations relative to ray finned fish.