1.  A.B. Lyon(s) & G.W.. Lyon, eds. 1905.  Lyon Memorial:  Massachusetts Families.  Wm. Graham Printing Co., Detroit, MI.

2.  Ahnentafel of the ancestry of Henry LYON from the database of the Lyon(s) Families Association, courtesy of database manager, Bruce C. Lyon.

2.  Richard LYON: b. 1590, Glen Lyon, Perthshire, Scotland  4.  William LYON: b. 1540, Little Stanmer, Middlesex, England; d. 1 Sep 1624, Little Stanmer, Middlesex, England  5.  Isabelle WIGHTMAN: b. ca. 1559, Harrow-on-the-Hill, Middlesex, England  8.  John LYON: b. 1510, Rystippe, Middlesex, England; d. 3 Oct 1592, Middlesex, England  9.  Jean ???: d. 15 Apr 1535 10.  William WIGHTMAN 11.  Audrey DEERING

I'm told that these data, which are from Sidney Lyon's (1907) Lyon Memorial, are now believed to be incorrect, at least with regard to Richard.

3.  LDS.  Family Search: Internet Genealogy Service:  IGI - International Genealogical Index (online at FamilySearch.org).

Name	Spouse	Marriage Date	Place of Marriage	Source
William LYON	Isabell WIGHTMAN	Abt. 1587	Scotland	Patron submitted forms
William LYON	Isabell WIGHTMAN	Abt. 1587	Scotland	Patron submitted forms
William LYON	Isabel WIGHTMAN	Abt. 1579	Of Little Stammer, Essex, England	Patron submitted forms
William LYON	Isabel WIGHTMAN	Abt. 1623	Of Glen Lyon, Perth Scotland	Official Temple record
William LYON	Isabel WIGHTMAN	Abt. 1579	Heston, London, England	Patron submitted forms
William LYON	Isabell WIGHTMAN	17 Jun 1664	Of Heston, London, England	none given

Why do I doubt that anyone has a valid marriage record for this couple?  Not to mention the one 40 years after the husband's death (though this appears to be a typo for 1646, which makes it only half as absurd).  It is also unlikely that William was married in 1623 in Scotland, then fathered three sons, including one in 1621, before he died in 1624 in Middlesex.  Little Stanmore is in Middlesex, not Essex.  I don't doubt that William and Isabelle were married.  I do doubt that anyone is more than guessing as to when and where.

4.  LDS.  Family Search: Internet Genealogy Service: Pedigree Resource File (index to CDs, online at FamilySearch.org).

William Lyon h/o Isabel Wightman b. abt 1535, Little Stanmore, Middlesex, England d. 7 Sep 1624, Little Stanmore, Middlesex, England s/o John & Joan Lyon

William LYON, m. 17 Jun 1646, Isabell WIGHTMAN b. 1540, Little Stanmore, Middlesex, England d. 7 Sep 1624, Little Stanmore, Middlesex, England s/o John & Joan Lyon

William LYON, h/o Isabell WIGHTMAN b. 1555, Ruislip, Norfolk, England d. 7 Sep 1624, Little Stanmore, Middlesex, England s/o John & Joan Lyon

William Lyon, h/o Isabell Wightman b. 1555, EN d. 1624, Little Stamner, Middlesex, EN s/o John & Joan Lyon

William Lyon, h/o Isabell Wightman b. abt 1555, Little Stanmore, Middlesex, Eng burial. 7 Sep 1624 s/o John & Joan Lyon

William Lyon, m. 1578, Isabel Wightman b. abt. 1555, Little Stanmore, Middlesex, Eng burial: 7 sep 1624, Little Stanmore, Middlesex, Eng s/o John & Joan Lyon

William Lyon, h/o Isabell Wightman b. abt. 1555, Little Stanmore, Middlesex, England d. 7 Sep 1624, Little Stanmore, Middlesex, England s/o John & Joan Lyon

William LYON, m. 17 Jun 1646, Isabell WIGHTMAN b. 1540, England d. 7 Sep 1624, Little Stanmore, Middlesex, England s/o John & Joan LYON

William Lyon, h/o Isabelle Wightman b. 1540, Little Stanmore, Middlesex, England d. 7 Sep 1624, Little Stanmore, Middlesex, England s/o John Lyon & Joan "Janet" Keith

When data are "all over the map" this way, you can be fairly certain there is little primary documentation to support them.  All seem to agree, and I don't doubt, that William LYON & Isabelle WIGHTMAN were married and that, apparently, John and Joan LYON were William's parents.  The one primary datum seems to be the burial record of William.  The marriage record in 1646 is absurd for a man who died in 1624.  I strongly doubt that William's parents were John & Janet (KEITH) LYON because 1) her name was Janet, not Joan; 2) William's mother, Joan, is said to have died in 1535 while Janet (KEITH) LYON was still living in 1559; and 3) John, as 7th Lord Glamis, was presumably living in Glamis, Forfarshire, Scotland, not Middlesex, England.  This is not the only source trying to fabricate royal connections to these LYONs.

5.  LDS.  Family Search: Internet Genealogy Service:  AF - Ancestral File (online at FamilySearch.org):

Husband's Name: William LYON [AFN: 9J65-64] Born: 1540; Place: Little Stanmore, Middlesex, Eng Died: 7 Sep 1624, Little Stanmore, MIddlesex, England Buried:  7 Sep 1624, Little Stanmore, Middlesex, England Father:  John LYON Mother:  Mrs. Joan LYON Married:  17 Jun 1646, Eng Wife's Name:  Isabell WIGHTMAN [AFN: 86X6-37] Born:  1559, Of Harrow-On-The-Hill, Middlesex, England Died: England Father:  William WIGHTMAN Mother:  Audrey DEERING Children: 1.  John LYON, b. 1568, Heston, Middlesex, Eng 2.  William LYON, b. 1580, Heston, London, Englsnd 3.  Isabelle LYON, b. 1582, Heston, Middlesex, Eng 4.  Audrey LYON, b. 1584, Heston, Middlesex, Eng 5.  Thomas LYON, b. 1585, Heston, Little Stanmer, Middlesex, England 6.  Robert LYON, b. 1590, Heston, Little Stanmer, Middlesex, England; d. 17 Oct 1678, Fairfield, Fairfield, Conn. 7.  Richard LYON, b. 1624/1625, Heston, Middlesex, England; d. 17 Oct 1678, Fairfield, Fairfield, Conn.

Why do these last two children make me feel someone is trying to force the data to fit some preconception?  And, of course, it's impossible for Isabelle to have birthed a child in 1624/5, when she was in her 60s.

6.  Family TreeMaker.  World Family Trees.  There are numerous pedigrees giving William & Isabelle (WIGHTMAN) LYON as the parents of a Richard LYON.  They all suffer from the data being "all over the map," just as is the case with the records from the LDS.

7.  Ancestry World Trees at Ancestry.com.  Ditto my comment on the previous source.