kinman2 at YAHOO.COM
Mon Sep 13 22:38:59 CDT 2004
By now I'm sure most zoologists have heard that "Myxozoa" are metazoans (not protists), but alliance of this group with cnidarian metazoans (Siddall 1995?, etc.) has been more recently challenged. It seems just as likely (perhaps more so) that myxozoans are simplified bilaterians.
However, the purpose of this post is not to discuss their exact phylogenetic placement (which remains to be seen), but rather problems with the proposed higher taxonomy that has been proposed. I have no big problem with the proposed Class Malacosporea (apparently the basalmost clade of myxozoans), although I still prefer to unite all myxozoans as a single Class Myxozoea. What I DO object to is the Order Malacovalvulida which (besides being a poor name, in my opinion) is junior synonym of Order Buddenbrockiida Kinman, 1994. I am also unsure where the heck they came up with Family Saccosporidae (is that based on a generic name??).
In any case, Order Buddenbrockiida Kinman, 1994, has priority, and additionally the genus Buddenbrockia probably represents our best clue to the origins of myxozoans and their presumed placement among the Bilateria.
P.S. And don't be too surprised if the bivalved myxozoans are remnants of a very early radiation of ecdysozoans (whether they are directly related to nematodes or not). Remember my post here last year about primitive arthropods being bivalved? Perhaps there is some method in my "madness" after all?? Only time will tell, but I find new evidence very encouraging (and I still have no doubts that Lophotrochozoa is a muddle mess that should be abandoned!!). If I am correct, all ecdysozoans had bivalved ancestors---including the onychophorans and anomalocareans (the latter would probably be clearly confirmed if new Hurdia specimens were ever described instead of sitting in someone's museum drawer for well over a decade).
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