Pedro Márquez was present at the 1540 muster as an unassigned horseman. There are at least two different individuals with the same name and the documentary record does not shed light on if or whether either of them was the expeditionary.
1530-1540:
?AGI, Pasajeros, L.2, E.2132 = Boyd-Bowman, Indice geobiográfico, II:189 [August 18, 1535, Pedro Márquez, son of Pedro Sánchez de Mayoral and Juana Martín, citizen of Orehuela, to New Spain]
1540-1550:
1540, Feb: Muster in Flint & Flint, Documents, Document 12 [2 horses, native arms]
?AGI, Justicia, 260, Pieza 1 [1543-1547: witness: Francisco Rodríguez, wineskin maker, vecino of Mexico City; witnesses to be called: don Tristan de Arellano, Francisco de Godoy [fol. 183v]; Juan Franco, carpenter, alarife of Mexico City, Juan Gallego [fol. 184v]; Pedro Márquez, citizen of the city in which his testimony was taken [fol. 185r]; don Luis de Quesada, vecino of Mexico City [fol. 185v]; [fol.605r: witness: vecino of Mexico City, more than 23 years old, native of Puerto de Santa María in Castilla, came to Nueva España 8 years ago (this may be the one who could not write in 1543)];
?AGI, Justicia, 270, Pieza 5 [1543 witness in México is Pero Márquez, about 25 years old, did not known how to sign his name; testifies about the alguazil playing cards in México];
?AGI, Contratación, 197, N.21, R.1 [24 March 1545, witnesses to a will, Hernán Pérez; Mexico City, purchased items by Juan de Cepeda, Pedro Márquez; also goods of Alonso de Castro, 1545, Mexico City, tutor and curador for the mestizo children of Castro is Francisco Gómez, merchant and vecino, signed (no signature on copy)];
?AGI, Justicia, 272, Pieza 14 [includes a list of documents from 1542 and 1543 in Méndez's possession which shows "otro de Pero Márquez contra Hernando de Horduña esta perdida la querella"]
?AGI, Contratación, 197, N. 29/16 [Bienes de difuntos, Gómez de Albizuri; in la ciudad de San Pedro de Puerto de Caballos, Honduras, in August 1551, a Pedro Sánchez Naveros?, vecino and, in 1549, alcalde de la ciudad de San Pedro, is the agent of Pedro de Durango Guipusquano, albacea for the deceased; death occurred in September 1549; Albizuri, a merchant, held promisory notes from Sánchez Naveros, a Juan Pérez, an Antón Pérez, a Diego Hernández de Gibraleón, vecino de San Pedro; a Pedro Hernández, zapatero; a Pedro Márques, difunto; Diego Hernández de Gibraleón purchases items during the almoneda; payment is made to another Pedro Hernández, carpintero who made the coffin--this man fled to Nueva España during the proceedings; and to yet another Pedro Hernández, pinero; a large amount of merchandise is auctioned off]
1560-1570:
?AGI, Contaduría, 667A [diezmos de plata, 1562: a Pedro Márquez diezmo 101 marcos de plata in December]
?AGI, Patronato, 122, N.1, R.1 [Méritos y servicios de Gaspar Miguel Ruíz de Rojas en el descubrimiento y pacificación de la provincias de Meyobamba y Bracamoros con los capitanes Juan Procel y Juan Pérez de Vergara, 1577, begins 1561: Ruíz de Rojas is vecino de la ciudad de Mendoza en la provincia de Chile, more than 60 years old, has been in the provincias of cuyo more than 15 years (since about 1556), was a poblador and has served more than 35 years, is ordered to go to Spain to get his wife who lives in Sevilla, but protests that he is too old, too poor, too weak; he was with Vaca de Castro and Gasca; came to Peru with Francisco Hernández Girón in about 1541; was alguazil mayor of Mendoza; was with Pedro del Castillo in the conquista of the provincias de Cuyo; me halle con los capitanes Joan Porcel y Juan Pérez de Vergara en el descubrimiento y conquista y pacificación de las provincias de Moyobanba y Bracamoros...donde estuve tres años; a Juan de Villegas (more than 35 years old in 1561, alcalde ordinario de Mendoza, has known Ruíz de Rojas since 1541, testifies, as do a Francisco de Vargas (morador en Santiago, could sign) and a Pedro Alonso de Vargas (morador in Lima), testimony in Lima, May 1577; all had been in Santiago); in Mendoza in 1561 a Pedro Márquez, procurador mayor, is a witness, is about 35 years old, signs]
1570-1580:
?Catálogo, Resumen e Índices [1576, Bernardo Moreno, carretero, vecino, vende a Luis Gómez, vecino: [...] No firmó. Testigos: Gabriel de Villalobos, Pedro Márquez y Antonio Guerrero, vecinos y estantes]
Other Info: ?Enciso Contreras, Testamentos [p.276: reference-AGI, Contratación, 221, N.1, R.6, will of Alonso Díaz de la Pedrera, a criado of Gonzalo Hernández, called Márquez, was found alive after the attack by the Chichimecas];
?Piferrer, Nobiliario, 3:153, #1321 [Lorca, Vizcaya; escudo - 3 red bands on a field of blue; members have settled in Cuevas along the Almanzora river];
?Ortíz de la Tabla Ducasse, Quito [p.167: in charge of mill of Rodrigo Núñez de Bonilla in Cuenca, Ecuador]