So what do you see? A groove and some lines? Truth be told, this is possibly the oldest recorded chordate fossil (or, should I say, one of a number of seventeen specimens of same). It dates from the pre-Cambrian – i.e. before 543 million years ago – during a period known as the Ediacarian. Found by Ross Faraghar seven years ago in the Flinders Range of Australia, the specimens represent our earliest view of chordate evolution, that is, the evolution of the group that we belong to (along with a few squishy things, and the more familiar fish, amphibians, reptiles, and mammals). Unfortunately, the specimens have not yet been formally described, but if they hold up as a chordate, then it is clear major body plans did not all develop in the Cambrian explosion, but were developing and diversifying long before this (as hinted by genetic data). Thus, perhaps, the “explosion” was one of hard body parts rather than of major body plans. As “SteveSteve” comments over at the Panda’s Thumb, it is
[a] tadpole-like beastie similar to the chordate amphioxus. Clear muscle bands, small fin fringe, traces of what could be gill structures and a possible sensorium on the “head” area. This is pretty much what was predicted by scientists based on the finds of the primitive chordates Yunnanozoon and Pikaia in the Cambrian. Also, the Ediacaran chordate is consistent with several DNA studies which suggest that chordates arose in the Ediacaran. The main impact of this find is that the “Cambrian Explosion” is dead. Yes, there was a period of rapid diversification (if you want to call a period of 30-60 million years rapid) when animals developed hard parts. But this was preceded by a long period of time when basic body plans were developed. ID creationists claims that all animal body plans developed in an implausibly short period of time in the Cambrian are refuted by this small tadpole-like ancestor.
Where this becomes important is that (as noted here), John West of the Discovery Institute has “indicated that any discovery of precursors of the animal body plans that appeared in the Cambrian period 500 million years ago would cast doubt on the thesis that those plans, in defiance of Darwin, evolved without a universal common ancestor.” In other words, by West’s own admission, if this holds up as a chordate – or even an ancestor of chordates – we have evidence against the claims of Intelligent Design supporters.