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"Finding a modern cylindroleberid in the Silurian clashes with molecular data,

A statement of overwhelming merit--if you happen to have the DNA of that silurian to compare with its modern cousins' DNA.

Creatures maintain physical form through substantial DNA drift--most multi-cellulars change much more in response to viruses than to environmental changes that would reflect in changes in physical morphology.

which suggest that the group and related families originated relatively recently, says evolutionary biologist Todd Oakley of the University of California, Santa Barbara."

So does finding silurian creatures above dinosaurs, or finding a dinosaur bone in the silurian, until we remember that a billion or so years is a long time for good data to lie about undisturbed by time and chance and to hold our water until we have a statistically significant weight of finds, and an understanding of what continental folding and erosion has done to the strata in question.

There is nothing new about this--it happens all the time, it just doesn't usually go so high up the Tree of Life as to make the news. And this news is premature--I see no signs of plans afoot to make any such revision on the basis of this evidence, as yet.

Another Missing Link Demoted 11/12/2003
The microscopic protozoan Giardia may be the bane of hikers who like to drink creek water, but it has been the boon to evolutionists as their missing link between prokaryotes and eukaryotes – until now. New findings “mark a turning point for views of early eukaryotic and mitochondrial evolution,” report Katrin Henze and William Martin in the Nov. 13 issue of Nature¹, summarizing work by Tovar et al.² in the same issue: “Giardia’s place as an intermediate stage in standard schemes of eukaryotic evolutionary history is no longer tenable.” They comment that this paper “will surprise many people.”
What happened? Central to the missing-link idea was the belief that Giardia lacked mitochondria, the ATP-energy factories common to eukaryotes (cells with nuclei, as opposed to prokaryotes, which lack them). Lo and behold, the researchers found tiny mitochondria, dubbed mitosomes, had been present in the little germs all along. And they are not just shriveled up versions of the big ones. They have a unique biochemical path that produces ATP without oxygen, required for their anaerobic environment. They build iron and sulfur clusters and then organize them into oxidation-reduction transport machinery.
So it seems evolutionists have to start over in their search for a new candidate to bridge the gap between the two kingdoms. But all is not lost by the finding; it helps shed light on alternative mitochondria, ones that don’t need oxygen:

We know [sic] that mitochondria arose [sic] as intracellular symbionts [sic] in the evolutionary past. But in what sort of host? That question still has biologists dumbfounded. In the most popular theories, Giardia is seen as a direct descendant of a hypothetical eukaryotic host lineage that existed [sic] before mitochondria did. But Tovar and colleagues’ findings show that Giardia cannot have descended directly from such a host, because Giardia has mitosomes. So our understanding [sic] of the original [sic] mitochondrial host is not improved by these new findings, but our understanding of mitochondria certainly is. In its role as a living fossil from the time of prokaryote-to-eukaryote transition, Giardia is now retired. But it assumes a new place in the textbooks as an exemplary eukaryote with tiny mitochondria that have a tenacious grip on an essential — and anaerobic — biochemical pathway. (Emphasis added in all quotes.)

¹Katrin Henze and William Martin, “Evolutionary biology: Essence of mitochondria,” Nature 426, 127 - 128 (13 November 2003); doi:10.1038/426127a.
²Tovar et al., “Mitochondrial remnant organelles of Giardia function in iron-sulphur protein maturation,” Nature 426, 172 - 176 (13 November 2003); doi:10.1038/nature01945

Also of interest in this report is Henze and Martin’s admission that the whole story of eukaryote evolution is slightly less than watertight: “The prokaryotes came first [sic]; eukaryotes (all plants, animals, fungi and protists) evolved from them [sic], and to this day biologists hotly debate how this transition took place, with about 20 different theories on the go.” Hate to break it to them on an already bad day, but the endosymbiont theory is not as watertight as they assume, either (see a rebuttal by Don Batten.)
Even assuming their assumption, Tovar et al. admit that whatever this endosymbiont was, it was not a simple clod: “Thus, the original endosymbiont must have possessed the capacity to synthesize Fe–S clusters and to assemble them into functional redox and electron transport proteins.” If you don’t know how to do that, don’t expect that a germ figured it out millions of years ago.