@Ionus,
I never really implied to the completeness of the available DNA data from Smilodon. I knew they hadda use a PCR tehnique to amplify the DNA data they had so I just assumed that they had a complete enough batch to do a Phylo... tree analyses. I WAS WR WR WR WRONG
In fact, to make your point even more disturbing , the overall sequencing that has been accomplished for Smilodon (as a genus), actually comes from BLAST analyses
Basic Local Alignment Search Data of the mDNA of several Smilodon species that had never ever "met for lunch". This means that they smooshed all the Smilodon DNA data they had and drew their tree from this "Commitee of data"
After considering your point about "bits of DNA", I went to a series of sequencing papers by a dude named Dzhabarov who displayed phylogenetic trees of a "generalized Smilodon" based upon using the BLAST program on S fatalis (the US speies from Kansas sites and , of course, the TAR PITS), S gracilis (another US speciemn that went extinct 10's of thousands of years before S fatalis) {THAT KIND OF PISSES ME OFF because its "SMUDGING" the data that lets us understand the subsequent radiating of other big cats from SMilodon (IF THAT WAS EVEN THE CASE)
And, , to make matters even more complex, Dzhabarov "added in", some yDNA and mDNA from a S populator (which lived exclusivley in S America along the Andes. So it development was fairly recent but still, it had its own thousands of generations of its own evolutionary path.
These data imply that we can do a phylogenetic tree about "Where Smilodons diverged from", but we really have to be careful about "what did Smilodon turn into (if anything)"
It took Planck Institute a decade or more to fully sequence neanderthals DNA and do it well before they could safely announce a conclusion that Neanderthals DID interbreed with humans. (I remember hen Paabo released his first bit of DNA data and denied any Neanderthal genetics in our own genoms and he was speaking too soon.
I must acknowledge that you are correct and that the overall sequencing of Smilodon is somewhat of a patchwork.(DNA degrades and the tar pit data is especially non-upportive even though it contains samples from the most recent drowned specimens) I suppose the full and correct (descendent implied) genome of S populator and S fatalis andS gracilis, will need the help of PCR (xeroxing) and lots more DNA samples.
Thank you for bringing out that detail . I shall try to be more discerning and critical over DNA data from papers placed on the web ( I assumed they were juried) when its being used to do develop implied "detailed" phylogenetic trees .