Fellow blogger Beneath Thy Feet explained the significance of it to me as Time arrriving to claim his due at the moment of the person's death. The arrow I guess represents the inevitable trajectory of existence - towards death.
The superscript motto reads: Time and Death shal be no more
So far I've found two of these type of carvings in Staffordshire: one in Audley churchyard, and this one, which is in Horton churchyard.
Taking a photo from the left side of the same carving more clearly shows the woman praying (she who is to become the skeleton I suppose), an hourglass, and, erm... three shapes whose significance I don't know! If you know what these three shapes represent, I'd be very happy to hear...
This post was featured on the Cemetery Sunday website