Here is what I have found on the web although I can't document it.
Shadrack's parents were Shadrack (1749) and Sarah Lantrip (Lanthrop).Shadrack (1749) b. 14 Dec 1749 Bristol Parish, Prince George county, VA.d. 178? in SC.Shadrack (1749) and Sarah had 5 children: Meshack, John, Shadrack, Thomas and Martha.
Shadrack's (1749) parents were Thomas and Hannah Lanthrop.Thomas b. 30 Dec 1727 Prince George County, VA.d. in SC.Thomas and Hannah had 3 children: Shadrack, Thomas and James.
Thomas's parents were John and Anne Lanthrop. John (1700) b. ~1700 Prince George County, VA.d. ?John (1700) and Anne Lanthrop had 2 children:Thomas and Margaret.
John's (1700) parents were John (1647) and Margaret Lanthrop.John (1647) b. 1647 in Yorkshire, ENGd. 1718 in Prince George County, VA.
John's (1647) parents were Petri and Elizabeth (Orwin)Lanthrop.Petri b. 1625 in Yorkshire, ENG d. ?Elizabeth b. 1644 in Yorkshire, ENG.