If you’re starting to see a recurring theme here, that is, that I spend a lot of time discussing types, I am glad. You are seeing the point, types matter, examining them is crucial. This particular case I am going to talk about some of the species in Emydura. Namely Emydura australis and Emydura victoriae, both of these names have issues, both require a complete assessment.
The species Emydura australis was named in the same paper as Chelodina oblonga by John Edward Gray (Gray, 1841). As I said in the case of Chelodina oblonga the specimens were collected in northern Australia in the years preceding this in an expedition that largely collected in what was then known as Western Australia. For many years Emydura australis was considered a valid name, it is certainly an available name. However in 1983 it was synonymized with Emydura macquarii by Hal Cogger, it was at the time thought to be the same species as it. This is in error. The holotype is most certainly from northern Australia in all likelihood from the Kimberley region of Western Australia. This is one of the oldest name in Australian turtles for a short necked species, the only older name being that for Emydura macquarii. The Principal of Priority would therefore have this name as valid, no matter what species it applies to. It is not a nomen dubium, it can be applied the holotype is very good and can be clearly seen as a Red-faced Turtle.
This of course makes it the oldest name for what we currently call Emydura victoriae. Well we have been in error for the last 31 years, not long enough to salvage the name Emydura victoriae through usage. So what about Emydura victoriae, this name also has problems as it is based on syntypes and the two specimens representing the species are not both the same species. One of them is a Northern Red Faced Turtle; the other is unfortunately a Murray River turtle. This is awkward if no one had done anything about it but unfortunately they have. Richard Wells and Ross Wellington have set a lectotype (Wells and Wellington, 1985) and the lectotype they chose was the Murray River Turtle specimen (Iverson et al. 2001). This cannot be overturned, except by the ICZN, and effectively places Emydura victoriae as a junior synonym of Emydura macquarii.
So the Northern Red-faced Turtle currently have several names that can apply to it, Emydura australis, which is incorrectly in synonymy, and Emydura victoriae, which is not actually a valid name for this species. How did this happen? Well because people did not examine the types. In 1983 I am sure Hal Cogger looked at the types, however the morphology and understanding of chelid turtles in Australia at that time was poorly understood, at best. This mistake is reversible and understandable. However by not examining the types and making the nomenclatural act of setting a lectotype, Wells and Wellington have effectively destroyed the name Emydura victoriae. Our concept of this species is represented by the non-name bearing type, the name cannot apply to the Northern Red-faced Turtle anymore. As I have said the name goes with the type that is the name bearing type, which is now a Murray River Turtle.
I have discussed what types are, how they are used and how important they are. This example demonstrates how easy it is to make mistakes that create a significant mess. So what can we do about this? There are three options, none of them easy and none of them that will not create a major problem in the nomenclature of the group. The following by the way is only commentary, I am not making any nomenclatural acts in this blog, I cannot. So please no-one is to consider this as such.
- The only one that will not require ICZN intervention is to follow the Principal of Priority and resurrect Emydura australis for the red-faced turtle and sink Emydura victoriae into Emydura macquarii.
- Make a case to the ICZN to conserve the name Emydura victoriae by overturning the Wells and Wellington (1985) lectotype and giving the name priority over the older name E. australis.
- Make a case to the ICZN to overturn the lectotype allocation and recognize both E. australis and E. victoriae as species. The populations represented by the two types can be distinguished, so there can be a case for recognizing both names.
Of these options the first one is the easiest and of the two that would require the ICZN to intervene the third option is more likely to succeed. Based on recent decisions and there reasons I am doubtful the second option would have any chance of succeeding.
The point here of course is examine the types. If you are not going to examine the appropriate material to do a taxonomic review that leads to nomenclatural acts, that is changes, that are set and cannot be undone; then I would argue you should not be publishing this material at all. The effects of what you do are wide reaching and have a serious flow on to other research areas. Your work will not be remembered well for acts that make a mess.