I think the idea of Crucifixion was to leave the bodies hanging
till the flesh was all eaten or rotted away,
and the bones tumbled to the ground
to just lie there as a greeting for future victims -
an eerie place where half a corpse or a ruckle of bones
might suddenly drop like a conker off a tree!
Jesus was probably exceptional in having friends to claim his body and bury him,
slaves and common criminals wouldn't have done.
Golgotha wasn't "Place of the Skull" for nothing.
I think there may be classical Crucifixion paintings
that pay attention to this detail,
I'll watch out for some.
not a Crux, but my favourite Andromeda
(Joachim Wtewael 1611)
has a surreal, Dali-like, collection of girls' skulls and bones,
mingling with exotic seashells,
around the deliciously lively-looking maiden's legs.