1990 Helen Roundtree
Pocahontas's People: The Powhatan Indians of Virginia Through Four Centuries
By Helen C. Rountree -Published 1990-Page 280
http://books.google.com/books?id=fUzd7LeJpjYC&pg=PA280&dq=manskin+indians&ei=dCDTR-fxGJG0yQTZqfTbCA&sig=7s0QGmPdZTjvNNuN8UXTOG01n3U
“29. Thus the sudden appearance of "new" groups of Indians within established tribal territories in the seventeenth-century Indian records. Examples are Old and New Nimcock within Opiscatumek territory, Machodoc within Sekakawon territory, Warrany within Chickahominy territory, Totuskey within Rappahannock territory, and Manskin with Pamunkey territory (see chap. 5).”
The “sudden appearance” is a logical response to a modern day researcher searching through the edited records available today. Manskins were listed in the earliest maps such as Zuniga and Langstons and almost every map made in the seventeenth century. Its is only the TEXT and translations from which they were eliminated, not the maps. And if the Yougtanund were absorbed into the Manskin, then they were actually there in the text all the time too.
Helen does mention in John Smith's Chesapeake Voyages, 1607-1609 (published 2007)
that she believes that Opechancanough could have been a Youghtanund.
http://books.google.com/books?id=5ceLAAAACAAJ&dq=helen+rountree+John+smith%27s+Chesapeake+Voyages&ei=VDHTR9twjMbIBN3O4JoL