“New Science Alert! You all may be familiar with common bottlenose dolphins, known by their scientific name, Tursiops truncatus. But did you know that there are three different ranging patterns for bottlenose dolphins off the East Coast? There are those that live in estuarine waters, those that migrate up and down the coast line, and those that live miles offshore. Well, scientists have recently proposed that coastal and estuarine bottlenose dolphins along the East Coast are actually a different species than the offshore form of bottlenose dolphins. After a decade of research analyzing DNA samples and morphological data from tissue samples, skulls, and vertebral columns, it was revealed that coastal/estuarine dolphins evolved independently from their offshore counterparts and are more closely related to dolphins in the Gulf of Mexico and Caribbean.
And with a new species, comes a new name! The scientific name, Tursiops erebennus, was chosen as this was originally used back in 1865 when the first description of a coastal bottlenose dolphin was published. The new common name is Tamanend’s bottlenose dolphin.
So what does this mean? Well if you see a local bottlenose dolphin around the Lowcountry, you’re looking at Tursiops erebennus, but if you head far offshore and see one, you’re looking at the true Tursiops truncatus! This new taxonomic designation does not change the existing stock boundaries or protection status of the dolphins under the Marine Mammal Protection Act. This also highlights how important it is to study dolphins (even the ones that die). Without the samples and skull specimens, this would’ve never been found!
Costa, A., et al. (2022). The common bottlenose dolphin (Tursiops truncatus) ecotypes of the western North Atlantic revisited: an integrative taxonomic investigation supports the presence of distinct species. Zool. J. Linn. Soc-Lond., 1-22.”
there wasn’t really a new species discovered, taxonomists decided to break two discrete populations of dolphins that used to be considered the same species into different species, but it’s the same dolphins as ever. It kind of bugs me to hear this stuff described as ‘discovering a new species’ as if someone out on the ocean found a pod of purple dolphins that had never been described by science before. This isn’t a bash at the person posting this at all either. But, i just find this stuff a little bit frustrating. Taxonomic splitting isn’t discovering new species.
It is neat to have this increased understanding of dolphin populations though.
charlie, I’d understand if the information or title was somehow sensationalized but nowhere does it say that a new species was “discovered”, in fact that word is not used at all. The paper is “The common bottlenose dolphin (Tursiops truncatus) ecotypes of the western North Atlantic revisited: an integrative taxonomic investigation supports the presence of distinct species” and it states that, “After a decade of research analyzing DNA samples and morphological data from tissue samples, skulls, and vertebral columns, it was revealed that coastal/estuarine dolphins evolved independently from their offshore counterparts and are more closely related to dolphins in the Gulf of Mexico and Caribbean”. That hardly sounds like taxonomists frivolously deciding to split a species. But that’s just my humble opinion.
I’m not saying the decision to split them was frivolous, i know nothing about dolphin taxonomy so i have no idea if the split makes sense or not. I am just saying it isn’t a new species, it is a new way to look at existing known dolphin types.
I’m not sure what the process is for mammals specifically, but for some groups iNat has a taxonomic reference/authority that they use for determining what species are available (though there’s also the ability to deviate from that if curators think it is warranted).
For other groups that don’t have a reference authority, taxonomy is curated in a more ad hoc fashion - users can flag groups on iNat and ask curators to add species or make changes that they feel are warranted, generally providing some type of source to support whatever changes they want to make.
Curators will ideally have a discussion with a few folks who are familiar with the situation in question on the flag and then either make a change or not.
But isn’t that how individual species often come into being, populations becoming separated and develop characteristics that make them different enough that they are no longer considered the same? Wasn’t that the whole thing with the Darwin’s finches on the Galapagos?
Thanks, @cthawley, I did just see something like this with the Dione/Agraulis discussion. Maybe I’ll just leave this alone until there is some additional verification.
Well, that particular situation was a major mess because it affected so many observations. For something like this, it would be much less likely to be a problem - though it might require some fancy “atlasing” to separate the observations by location, since that would seem to be the only way for someone to reliably ID an individual from one of these two species.
I think it often is good to wait to see whether the proposed species is accepted and makes its way into wider usage before being added to iNat. Especially in cases like this where location will be the only character used for ID - there’s not a strong benefit to getting the new species available ASAP. Someone who is interested in this species could easily lD them as the new species for their own purposes very quickly in GIS or otherwise. That said, I don’t think it hurts in general to raise a flag on a taxon on iNat to ask a question like this for a curator to look at - then the conversation is in the record and can be used in the future.
And, also to your point about ID, I was coming to that realization as well; that it would be based almost certainly solely on location with no ability to validate, being distressfully imprecise.
Yes. Flag it. Someone who is more familiar with the evidence and consensus will action it. If it is three cryptic species, for example, then a complex can be made and applied to the geographic area, and the new species nested under that complex. Because they are dolphins, and dolphins tend to wander in weird places outside their range, it’s likely that any local species or subspecies in each home range would only be identifiable as populations, not individuals, and sometimes based on their behavior. This already exists with killer whales, but there’s not even a flag so I doubt people will be jumping on this one.
Far from an expert here, but I’ve learned to somewhat differentiate potential off-shore from in-shore/estuarine bottlenoses from size, color, and rostrum length as we occasionally have them come into the shallower W New York Bight where we do typically only see coastals
Sounds like this wasn’t even a new name but was proposed in the 19th century for coastal populations, sunk into synonymy under truncatus, then resurrected in this paper. Probably very difficult to come up with a truly new scientific name for any mammal that has been known to science for a century or more.