Tailless Whipscorpions - Amblypygi

This post is to help me get my head around the Tailless Whipscorpions (Amblypygi) prompted by @sjl197's generous help on one of my obs today.

Global overview

There are 5 families:


Just 1 species (Paracharon caecus) from west Africa


1 genus Charon in Southeast Asia/Oceania


7 genera:
Damon (Africa)
Euphrynichus (Africa)
Musicodamon (Africa)
Phrynichodamon (Africa)
Phrynichus (Palaeotropics)
Trichodamon (South America)
Xerophrynus (Africa)


Restricted to the Neotropics aside from Phrynus exsul on Flores/Rinca Islands in Indonesia:
Acanthophrynus (Mexico)
Heterophrynus (South America)
Paraphrynus (Mesoamerica)
Phrynus (Mesoamerica & Flores/Rinca in Indonesia)


The most speciose family with the broadest geographical distribution (see Miranda et al 2022).
Charinus (a pantropical distribution)
Sarax (arcs from Greece through Asia)
Weygoldtia (around Vietnam)
Catageus (1 sp, Myanmar)

United States

In the US there are 4 regular species all in Phrynidae in the 2 genera Paraphrynus (2 sp Florida and Arizona) and Phrynus (2 sp Florida and Texas). The 2 genera can be separated based on shape of the pedipalp tibial spines (see figs 4 & 5 here). There are 2 spines between the longest 2 spines in Paraphrynus (thank you @mason_s) and just 1 spine between the longest 2 spines in Phrynus (thank you @fmcghee)

Costa Rica

In Costa Rica there are also 4 species in the same 2 genera Paraphrynus and Phrynus.
@sjl197 says that in Costa Rica what that document calls Phrynus gervaisii are now considered Phrynus barbadensis (is there a source for that?). Which would make the 4 Costa Rica species:
Paraphrynus laevifrons
Phrynus barbadensis (rather than Phrynus gervaisii)
Phrynus pseudoparvulus
Phrynus whitei


At the time of this writing I have a couple of questions I want to look into more, mostly to get a handle on North American Amblypygi:

1) How do you distinguish Charinus from Phrynidae in the Americas where they both occur?

2) How do you distinguish Phrynus exsul (the only Old World member of the otherwise New World family Phrynidae) from other Charon species that occur on Flores and Rinca Islands?

3) How do you distinguish the two New world members of Phrynichidae (Trichodamon froesi and Trichodamon princeps) from each other. Are the strikingly wide pedipalps a good way to distinguish them from Phrynidae and Charinus?

4) US and Costa Rica species are pretty straightforward, but what about the ones in between (e.g. Mexico, Guatemala, Belize, Honduras, El Salvador, Nicaragua)? Are there no Charinus species in these countries? (hard to tell from Miranda et al 2022 Fig 2)

5) Whats going on in the Caribbean? (there it does look like alot of Charinus species are involved)

To dos

1) Read this paper on Colombia as mentioned here

2) Coarsen these obs of Phrynus operculatus that occur south of Guatemala to fix incorrect IDs and/or engage in good conversations if people think this species does extend this far south

Publicado el 11 de enero de 2023 a las 12:53 AM por loarie loarie


Nice guide ! The genera would look better in italics tho ;)

Here is the source for Costa Rican species and here the source for the synonymy for P. gervaisii and P. barbadensis.

As for your questions, I'm not an amblypygi expert, especially in their taxonomy, but I can provide some insights, I'll ask around to verify this too :
1 - Charinus species are much smaller than any Phrynidae species, I don't know of any exceptions to this but there may be.
2 - Also, Phrynidae differs from all the other families by having no pulvili on the walking leg tarsi (visible on great pics only) and chelicerae with 3 denticles in the inner row (dissection only). Charontidae differ from most other families by having the pedipalp tibia dorsally with 2-3 large spines of equal size (Weygoldt, 2000).
3 - I don't know, the description papers should answer this.
4 - I'm pretty sure there are Charinus species in those countries, would be better to ask the authors what they think.
5 - In terms of biogeography :) ? I just know it's a place of great endemism for arachnids.

I hope that helped !

Edit : I was just informed that at least one described species of Charinus in Belize

Anotado por jtch hace más de un año

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