
已知椭圆\(C\):\( \dfrac {x^{2}}{a^{2}} + \dfrac {y^{2}}{b^{2}} =1(a > b > 0)\)的左,右焦点分别为\(F _{1}\),\(F _{2}\),上顶点为\(B.Q\)为抛物线\(y ^{2} =12x\)的焦点,且\( \overrightarrow {F_{1}B} \boldsymbol{⋅} \overrightarrow {QB} =0\),\(2 \overrightarrow {F_{1}F_{2}} + \overrightarrow {QF_{1}} =0\).
\((\)Ⅰ\()\)求椭圆\(C\)的标准方程;
\((\)Ⅱ\()\)过定点\(P(0 , 2)\)的直线\(l\)与椭圆\(C\)交于\(M\),\(N\)两点\((M\)在\(P\),\(N\)之间\()\),设直线\(l\)的斜率为\(k(k > 0)\),在\(x\)轴上是否存在点\(A(m , 0)\),使得以\(AM\),\(AN\)为邻边的平行四边形为菱形?若存在,求出实数\(m\)的取值范围;若不存在,请说明理由.