What is the Abbreviation ? is this Sotomayor ?
The name appears as Fernando Martinez Sotoma. with a small 'r' above the " a."

Comentario

Fernando Martínez de Sotomayor was the son of Antonio Martínez de Sotomayor and María Valenzuela according to his dispensa - https://familysearch.org/pal:/MM9.3.1/TH-1-18413-9191-35?cc=1874591&wc=…

Fernando's brother, Joseph Antonio, also had a dispensa which mentions in more detail their ancestors -
https://familysearch.org/pal:/MM9.3.1/TH-1-18410-40916-67?cc=1874591

Antonio Martínez de Sotomayor was the son of Andrés Martín de Sotomayor y González who married Beatriz de Mayorga 13 June 1666 in Aguascalientes. She was the daughter of Alvaro Marín de Peñaloza and Isabel de Mayorga
https://familysearch.org/pal:/MM9.3.1/TH-266-12446-30193-28?cc=1502404&…

Andrés Martín de Sotomayor y González was the son of Andrés Martín de Sotomayor and María González de Islas y Moctezuma.

Andrés Martín de Sotomayor was the son of Andrés Martín Camacho and María de las Ruelas o Sotomayor.

Alvaro Marín de Peñaloza was the son of Juan Marín de Peñaloza and María de Sandi

Comentario

Hello, Armando. I have been stuck on exactly the marriage you mention between Joseph Miguel Romo de Vivar and Isabel Rosaura Lopez. I would like to know if you know who the parents of Joseph Miguel were, and if you have further ancestors on him. I am trying to fill in my family tree as far back as possible through the Romo de Vivar line at the moment. The following is a link to specify who exactly I'm referring to, in case there are more instances of these names. https://www.familysearch.org/ark:/61903/1:1:NRPM-Y5W?from=lynx1UIV8&tre…

Comentario

I would think it is indeed Sotomayor, in these documents abbreviations usually the last letter or letters are written as superscript.
Regards,
Victoriano Navarro