A dynamic bone anchor is provided comprisingan anchor member (1, 1′, 1″) having a first end (11) and a second end (12) and a tubular section (13) between the first end and the second end, a longitudinal axis (L) extending from the first end to the second end, an outer surface and a bone engagement structure (14) for engaging the bone in at least a portion of the outer surface； anda longitudinal core member (2, 2′, 2″, 2″′) being at least partially provided in the tubular section (13) and being connected to the anchor member at a second portion (22a) of the core member and having a first portion (21a) that is not connected to the anchor member and that is movable with respect to the anchor member, characterized in that the core member is made at least partially of a first material that comprises a Ni—Ti based shape memory alloy, preferably the first material is Nitinol.
