  Using a sample of $1.06\times10^8$ $\psi^\prime$ mesons collected with the
BESIII detector at the BEPCII $e^+e^-$ collider and $\chi_{cJ}$ mesons produced
via radiative transitions from the $\psi^\prime$, we report the first
observation for $\psi^\prime\to \bar{p}K^+\Sigma^0 +c.c.$ (charge-conjugate),
as well as improved measurements for the $\chi_{cJ}$ hyperon decays
$\chi_{cJ}\to\bar{p}K^+\Lambda+c.c.$. The branching fractions are measured to
be $\mathcal{B}(\psi^\prime\to \bar{p}K^+\Sigma^0+c.c)=
(1.67\pm0.13\pm0.12)\times10^{-5}$,
$\mathcal{B}(\chi_{c0}\to\bar{p}K^+\Lambda+c.c.)=
(13.2\pm0.3\pm1.0)\times10^{-4}$,
$\mathcal{B}(\chi_{c1}\to\bar{p}K^+\Lambda+c.c.)=
(4.5\pm0.2\pm0.4)\times10^{-4}$ and
$\mathcal{B}(\chi_{c2}\to\bar{p}K^+\Lambda+c.c)=
(8.4\pm0.3\pm0.6)\times10^{-4}$, where the first error is statistical, and the
second is systematic. In the decay of $\chi_{c0} \to \bar{p}K^+\Lambda + c.c.$,
an anomalous enhancement near threshold is observed in the invariant mass
distribution of $\bar{p}\Lambda+c.c.$, which cannot be explained by phase
space.
