How do you identify Triops species?

Nature Talk
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I’ve recently been obsessed with Triops, attempting to raise some at the moment in fact. But anyway, I can’t seem to find any information on the morphological diagnosis and differentiation of the species, not even the ones commonly seen in captivity. I have even heard somewhere that morphology is unreliable and it’s more accurate to judge species based on locality.

The more pictures I look at, the more the general body shapes blur into each other. I had thought that a body shape like this was exemplary of T. granarius, with a round carapace and long tail, but apparently, if not misidentified, T. longicaudatus can look like that too! And T. granarius can also have an oval carapace and shorter tail. So it must be something finer. But again I haven’t managed to find anything.

So what is actually the difference? Not only between those two of course. Interested in hearing about all of the species.

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This might be a place to start but I haven’t managed to download it, despite it appearing to be available through Google Scholar:

Brendonck, L., Rogers, D.C., Olesen, J. et al. Global diversity of large branchiopods (Crustacea: Branchiopoda) in freshwater. Hydrobiologia 595, 167–176 (2008). https://doi.org/10.1007/s10750-007-9119-9

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The genus is global in distribution so I’d start with where you are. T. longicaudatus is supposed to be the common one in my area (SW US) but there’s at least another species and my one photo record is still sitting at genus.

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Thanks, looks like I’m able to download it with institutional access. Unfortunately it also says that

The Notostraca exhibit plasticity in external morphology, making the demarcation of species on this basis a difficult task

and doesn’t offer much help in morphological identification, which this paper seems to imply is not a reliable method of species diagnosis, at least when compared to phylogenetics.

However that paper did lead me to another: https://doi.org/10.1651/10-3411.1

Which mentions the use of legless abdominal rings, posterior carapace teeth, and egg color in distinguishing T. newberryi and T. longicaudatus. But the ring and teeth counts are variable with overlap between the species. Not too reassuring to be quite honest. But at least it does say that the former has lighter colored eggs while the latter has dark red eggs, so I guess that’s one, between these two species at least.

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Unfortunately I live in a part of the world without them (Java). The closest ones to me would be all the way in Australia.