In that case, here’s a fist-sized snail from New Zealand that eats earthworms: https://www.inaturalist.org/taxa/91282-Powelliphanta
And a two-foot-long bright red leech from Borneo. Which also eats earthworms. https://www.inaturalist.org/taxa/889425-Mimobdella-buettikoferi
And a bright yellow spiny woodlouse from St. Helena (which does not eat earthworms): https://www.inaturalist.org/taxa/496324-Pseudolaureola-atlantica
Holothyrida, an entire order of parasitiform mites endemic to various indo - pacific islands. Well at least Holothyridae and Allothyridae are. Neothyridae occur on mainland south america but there are no observations or Neothyrids on inaturalist. Very little is known about holothyridan mites other than that feeding tests on Allothyrids have confirmed they strictly eat dead arthropods.
https://www.inaturalist.org/taxa/144131-Holothyrida
Anaspidacea, an order of Malacostracan that is entirely limited to freshwaters of the southern hemisphere. Their phylogenetic placement is uncertain but they may well be related to decapods. Most of their diversity is in Australia and New Zealand, though a few species occur in south america. But again, no south american species have been observed.
https://www.inaturalist.org/taxa/85500-Anaspidacea
Heterojapyx, the world’s largest dipluran. They can range from 50 to 80 mm which is colossal for a dipluran. They are mostly in Australia and New Zealand, though one species occurs in China. And it seems theres one observations in south Africa? I have a feeling this one might not be a heterojapygid, though I cant say for sure.
https://www.inaturalist.org/taxa/376587-Heterojapyx
How interesting, I posted three taxa that are mostly but not entirely insular.
I see they’re all in an Acropsopilio situation.
Mostly Oceanian, but with a couple from elsewhere.
Parakermania, and incredible genus of isopods. See P. minima (the type species, description on page 142 here), P. maculata (illustration on page 78 here) and P. longa (see here). The species are found on the island of Hainan, except for the type species from the Bismarck archipelago.
Also take this spiky isopod from Flinders island (https://www.inaturalist.org/observations/9714722) and this cool one from a small part of Madagascar ( https://www.inaturalist.org/taxa/555765-Calmanesia )
Exceptions exist, not a problem. Just try to not add something with too many exceptions. And also just try to avoid such cases when possible.
But again Acropsopilio, I did not pay enough attention, should not be included. There is a very notable extrainsular presence of this genus.
In that case, here’s something neat.
It looks like a regular woodlouse, but it’s actually in an entirely separate although related group (basically every woodlouse is in Crinocheta, this one’s in Tylida), and it’s one of a handful of tylids that actually lives inland.
https://www.inaturalist.org/taxa/779774-Helleria-brevicornis
(I feel like you can tell I’m running out of weird critters after I posted several dozen :p)
Also, a bright pink New Caledonian springtail: https://www.inaturalist.org/taxa/873975
And a thrips that, for lack of a better word, has crab claws: https://www.inaturalist.org/taxa/1354801
Sandgropers are neat, but since they’re in South America too I don’t think they count: https://www.inaturalist.org/taxa/153282-Cylindrachetidae
A weevil that “looks like he bonked his head a bit too hard”: https://www.inaturalist.org/taxa/1576668
An entire subfamily of beetles with weird protrusions: https://www.inaturalist.org/taxa/1511689-Chlamydopsinae
Silverfish that look like velvet ants: https://www.inaturalist.org/taxa/1363626-Hemitelsella
A colourful flightless stonefly with small wings: https://www.inaturalist.org/taxa/893933-Thaumatoperla
A scorpionfly with a really, really long abdomen: https://www.inaturalist.org/taxa/785780-Leptopanorpa
Stenopsoides - Unique Australian leafhopper with a distinct digitiform process on the pronotum.
Acostemmini is found over several island groups and has only a single mainland species, Acostemma walkeri. Ikelibeloha cristata is one the coolest members of the group, from Madagascar.
Peggia nitida (from the Philippines) is by far, the craziest member of the Zoraidini.
Links to their pages on iNat:
Stenopsoides: https://www.inaturalist.org/taxa/1182519-Stenopsoides
Ikelibeloha (no obs): https://www.inaturalist.org/taxa/1175483-Ikelibeloha
Peggia: https://www.inaturalist.org/taxa/1113832-Peggia
Here’s an image of Ikelibeloha (go to Figures section): https://publication.plazi.org/GgServer/xhtml/03A1071DFFFDFFE4FF16FCDF6E47FD8A/4
Here’s some more vertebrates:
https://www.inaturalist.org/taxa/1289603
https://www.inaturalist.org/taxa/1584019
https://en.wikipedia.org/wiki/Magyarosaurus - a horse-sized sauropod (mirroring Palaeoloxodon falconeri)
https://www.inaturalist.org/taxa/145979 - teeny tiny chameleon
https://en.wikipedia.org/w/index.php?title=Special%3ASearch&search=Megalania&wprov=acrw1_0 - giant Komodo Dragon
https://en.wikipedia.org/wiki/Dodo - who can forget the dodo?
https://www.inaturalist.org/taxa/51727 - very, very big crab (not a vertebrate)
Stenopsoides was identified by me :)
This isn’t quite an example of a specific cool insular animal, but speaking of arthropods and islands I do want to showcase this. Arthropod faunas on islands tend to be better sampled than on mainlands due to their limited area. So I think this would be a good case test of the latitudinal diversity gradient.
| Island or Island Group | Area km^2 | Species Richness | Species/km^2 | Latitude |
|---|---|---|---|---|
| Seychelles | 457 | 3645 | 7.975929978 | -4.583333 |
| Madeiras | 801 | 3891 | 4.857677903 | 32.75 |
| Saint Helena | 121.8 | 443 | 3.637110016 | -15.966667 |
| Reunion | 2511 | 3369 | 1.341696535 | -21.114444 |
| Hawaii | 6424 | 6848 | 1.066002491 | 21.5 |
| Mauritius | 2040 | 2082 | 1.020588235 | -20.2 |
| Samoa | 3030 | 2774 | 0.915511551 | -13.745 |
| French Polynesia | 3521 | 2527 | 0.717693837 | -17.533333 |
| Azores | 2351 | 1476 | 0.62781795 | 38.66 |
| Marion | 297 | 126 | 0.424242424 | -46.9125 |
| Bouvet | 49 | 7 | 0.142857143 | -54.42 |
| Hispaniola | 76192 | 7787 | 0.102202331 | 19 |
| Iceland | 103125 | 1292 | 0.012528485 | 65 |
| Svalbard | 62045 | 552 | 0.008896768 | 78.22 |
| Greenland | 2166086 | 1260 | 0.000581694 | 72 |
Of course, stuff closer to the tropics has more species richness.
Normalizing by area largely gets the same results.
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Sorry, I just had this on me for a while and wanted to post it but didn’t think it was worth its own thread. Onto something more topical.
Craterostigmomorpha, a relict order of centipedes found only in Tasmania and New Zealand. They are the closest relatives of the Epimorpha (Scolopendromorpha + Geophilomorpha)
Cameronella, a wasp which looks like a dart: https://www.inaturalist.org/taxa/1464983-Cameronella
A host of flightless Hawaiian flies, like this one: https://www.inaturalist.org/taxa/790409-Campsicnemus-hao
The famous yet undescribed “silk angel moth” from Madagascar: https://www.inaturalist.org/observations/106687320
Hydropedeticus, a Fijian trig that lives in water: https://www.inaturalist.org/taxa/1577631
