Duskies (Desmognathus) have always been a confusing genus of salamanders. Most people struggle with the physical differences of these salamanders, but others like myself have noted some slight and some vast differences in their appearance among different populations. For example, I have long speculated that “Northern Duskies” (D. fuscus) in the Piedmont look more like, and may be, Flathead Salamanders (D. planiceps). Well, I was right in my observation but wrong in my conclusion. We have said that someone would have to DNA sample these Duskies to give us a full picture of what is really going on. Finally, Robert Alexander Pryon et al. have explored these species and came up with some interesting results. A few days ago, a massive new paper was published by them. This paper, “Candidate-species delimitation in Desmognathus salamanders reveals gene flow across lineage boundaries, confounding phylogenetic estimation and clarifying hybrid zones”, has loads of new genetic information. For example, the 22 species in this genus found in the eastern United States may grow to contain up to 47 species! What does this mean for Dusky species in Virginia? Well, here is a list of possible new species that may arise.
Basically, the geographical variation we have noticed is probably due to these one of two things: 1. These populations are new species, or 2. These populations are intergrades. This is confusing as several of these new species are the result of species diverging, intergrading, and then evolving in a different direction from their ancestors. A good example seems to be the Dusky referred to as “fuscus C1”. This salamander seems to be the result of the Holbrook’s Southern Dusky (D. auriculatus) and Northern Dusky intergrading back together, to create a new lineage that has evolved into a new species. Remember when I mentioned our Southern Piedmont specimens appear more like Flathead Salamanders? That is because they are actually fuscus C1. So we were right in saying they were very different in appearance with their more broken dorsal pattern and portholes on their tail but wrong in our interpretation that these were possibly Flathead Salamanders. This is one of several new species and name changes that could be coming.
So, let’s dive into the potential new species that might be found in Virginia. I know it's difficult to associate a letter/number to a name, so I will give a place-holder nickname for now, as it will probably be months or years before these get true names.
***This article has been updated with the new taxon changes! Remember, the species titles were predicted names by the author and the new names are bolded and underlined in the updates. Not all of these have been described as of yet, so several are still not updated.***
Upland Dusky Clade
Fuscus B2: "Northern Dusky"
Fuscus A: "Kentucky Dusky"
Fuscus E: "Yadkin Dusky"
Lowland Dusky Clade
Fuscus C1: "Southside Dusky"
Fuscus D: "Piedmont Dusky"
Monticola A/C: Seal Salamander
Marmoratus E/H: Shovelnose Salamander
Quadramaculatus D: "Northern Black-bellied Salamander"
Orestes C: "Mount Rogers Dusky"
These are the splits that will affect our Virginia species. I am excited about the prospects of this paper, and encourage all to read it; I have linked it below. If you think I missed anything, email us to discuss these new potential changes. I am not linking the newest paper, but the website for it as it is not a free version... Sorry...
Pyron, R. A., O’Connell, K. A., Lemmon, E. M., Lemmon, A. R., & Beamer, D. A. (2022). Candidate‐species delimitation in Desmognathus salamanders reveals gene flow across lineage boundaries, confounding phylogenetic estimation and clarifying hybrid zones. Ecology and Evolution, 12(2). Wiley Online Library. https://doi.org/10.1002/ece3.8574
Pryon, R.A., Beamer, D.A. (2023). Systematic revision of the Spotted and Northern Dusky Salamanders (Plethodontidae: Desmognathus conanti and D. Fuscus), with six new species from the eastern United States. Zootaxa, 5311(4). https://doi.org/5311.4.1
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