Ashkenazi Y-DNA Haplogroup T

Based upon the methodology posted here and using the sample set described here, as of January 2019 it appears that there are three substantial Y-DNA clusters in haplogroup T found in the Ashkenazi Jewish population: (1) T-BY11520; (2) the T-PAGES00113 subcluster of T-CTS8862; and (3) T-Y31472.  Trees for each of those clusters are posted below.

T-BY11520
Upstream SNPs: 
M184>L490>M70>Z19859>L454>L208>Y16897>Z19963>Z19969>Y28905>BY11520
ISOGG Tree (2019): T1a1a2a (Z19963)
TMRCA (YFull Tree)
T-Y28685: 1,050 ybp (600-1,500 ybp @95%) (T-Y28685 is one SNP upstream from T-BY11520)
T-Y34308: 850 ybp (450-1,300 ybp @95%)
T-BY28295: 600 ybp (300-1,150 ybp @95%) (T-BY28295 is at the same level as T-BY28287)
TMRCA (JewishDNA.net)
T-Y16897-BY11520 (AB-016): 367-903 CE

Based upon the age of T-BY11520 and the lack of upstream clustering with men in the sample set, it appears, pending further information, that T-BY11520 may have entered the Ashkenazi population in the early part of the last millenium.

T-CTS8862 (T-PAGES00113 subcluster)
Upstream SNPs: 
M184>L490>M70>Z19859>L131>L446>Y6055>CTS933>Z19939>CTS11984>CTS8862
TMRCA (YFull Tree)
T-CTS8489: 3,100 ybp (2,200-4,100 ybp @ 95%) (T-CTS8489 is at the same level as T-CTS8862)
T-CTS1848: 2,500 ybp (1,450-3,900 ybp @95%)
TMRCA (JewishDNA.net)
T-CTS8862 AB-017: 198 BCE - 977 CE (@95%)

Based upon the sample set, it appears that T-PAGES00113 may be the only Ashkenazi subcluster within the T-CTS8862 cluster.  Further information is needed to date that subcluster to determine when the line likely entered the Ashkenazi population.

T-Y31472
Upstream SNPs: 
M184>L490>M70>Z19859>L454>L208>CTS11451>Y4119>CTS2214>BY28451>Z709> CTS8512>L906>CTS8603>CTS6174>CTS4647>P77>CTS2860>Y4956>CTS6507>Y31472
ISOGG Tree (2019): T1a1a1b2b2b1a1a (CTS6507)
TMRCA (YFull Tree)
T-Y31474: 3,400 ybp (2,600-4,400 ybp @95%) (T-Y31474 is as the same level as T-Y31472)
T-Y31473: 2,600 ybp (1,800-3,500 ybp) (T-Y31473 is at the same level as T-Y31471)
T-Y91965: 450 ybp (200-950 ybp @95%) (T-Y91965 is at the same level as T-Z241760)
TMRCA (JewishDNA.net)
T-P77-Z41760 (AB-020): 1288-1706 CE (@95%)

The fact that there is a significant proportion of men from the sample set in both the T-Y31471 and T-BY39967 subclusters of T-Y31472 creates a significant likelihood that the T-Y31472 progenitor was from a proto-Jewish population.  

Y-DNA SNPs Not Appearing on Trees Posted Above
In addition to the SNPs posted above, there are a number of SNPs identified through the methodology used on this website that do not appear in any of the trees posted above.   In some cases, primarily with regard to SNPs reported by Family Tree DNA based upon the results of Big Y testing or Geno 2.0 testing, the reported SNPs are ancestral to the SNPs set forth in one or more of the trees above; if the tested man is Ashkenazi on his direct male line, Big Y testing would likely determine that he belongs to one of the clusters set forth above.  In other instances, it is possible that SNPs identify a small and/or undertested Ashkenazi cluster; further testing or information may identify such clusters.   Often, because the methodology used herein to identify potential Ashkenazi SNPs is overinclusive (especially for the 50 cM cohort but also, on occasion, for the 80 cM and 100 cM cohorts), SNPs set forth below do not reflect Ashkenazi (or Jewish) ancestry on the direct male line.  Finally, there are some SNPs (identified with "N/A") that do not appear on FTDNA's Y-DNA haplotree at all.

Upstream SNPs.  The following SNPs in the table above (identified in red) are upstream from SNPs found in one or more Ashkenazi Y-DNA clusters: CTS2214, CT6507, CTS8603, L208, L454, M70, P77, Y6055, and Z709.  

If men who are reported based upon STR or Geno 2.0 testing as having these SNPs are of Ashkenazi descent on their direct male line, there is a high probability that such men belong to one of those Ashkenazi Y-DNA clusters.  However, a large proportion of the men reported as having these terminal SNPs are not of Ashkenazi descent on their direct male lines.

Downstream SNPs that may reflect an Ashkenazi Y-DNA line.  The following terminal SNPs in the table above (identified in blue) do not appear in the Ashkenazi Y-DNA trees posted above, but may reflect an Ashkenazi Y-DNA line: FGC30190, and P317

Other SNPs.  With the exception of the SNPs that are not on FTDNA's Y-DNA Haplotree (identified with "N/A"), it is unlikely that men reported as having terminal SNPs other than the upstream SNPs identified above are of Ashkenazi descent on their direct male lines.