Both Forest et al. (2005) and Grimm & Renner (2013) provide dated trees.

PS This paragraph includes a common error: "Our molecular dating analysis supported Betulaceae to be originated at the end of Cretaceous (∼70.49 Mya), which is very close to the above results" – is nonsense. Origin would be the stem age, but your tree lacks the needed stem node (= MRCA Ticodendron and Betulaceae). This is also not a result because you constrained the divergence age of the MRCA Betulaceae to this age: "(1) the crown age of the family Betulaceae was set to 69.95 Mya (SD = 2.0) and assigned a normal distribution (Xiang et al., 2014)"