Alathyria jacksoni is the type species of the genus Alathyria, and from where we are sitting, it may be the only species that is really in that genus.
On this web site right now, we follow McMichael & Hiscock (1958), who largely followed Iredale (1934, 1943) in recognizing 4 species in Alathyria: A. jacksoni, A. pertexta, A. condola, and A. profuga. It is really interesting that Iredale's classification has held up for so long, since he was an F.C.-Baker-esque splitter who never found variation that didn't merit a new taxon. But Iredale, and later McMichael & Hiscock, grouped these taxa together because of their large size. These are the big Australian mussels.
But after 50 years or so, the addition of DNA into the analytical mix has demonstrated that this classification isn't natural. That is, it doesn't reflect evolutionary history. Back in 2004, Andrew Baker et al. discovered that A. jacksoni was nested within the genus Velesunio. That was the only Alathyria species they considered, but their result indicated some confusion regarding the genus-level taxonomy of the Velesunioninae.
Graf et al. (2015) have just published a new paper that puts another nail in the coffin of the traditional view of Alathyria. Their analysis included three species of Alathyria, A. jacksoni among them, and all three were found to be more closely related to species of other genera. There is still some work to do on the taxonomy and classification of Australia's freshwater mussels. When that revisionary work gets completed by the locals in Oz (hopefully taking advantage of all the specimen records we have made available on this site), we will update our classification.
Perhaps the neophyte to the field of systematics will draw from this outcome the conclusion that no predictive classification can be achieved without molecular data. But it isn't only the data that differ between the classical work of McMichael & Hiscock (1958) and the Earth-shatteringly rigorous modern analysis of Graf et al. (2015). We would instead emphasize the supremacy of repeatable cladistic methods to traditional authoritarian "Just So" stories. |
