Juan Valverde de Amusco (or "de Hamusco") was born in the Kingdom of Leon in what is now Spain in about the year 1525 and studied medicine in Padua and Rome under Realdo Columbo and Bartolomeo Eustachi. He published several works on anatomy, including De animi et corporis sanitate tuenda libellus (Paris, 1552).
Valverde's most famous work was Historia de la composicion del cuerpo humano, first published in Spanish in Rome, 1556. All but four of its 42 engraved copperplate illustrations were taken almost directly from Andreas Vesalius' De humani corporis fabrica. Vesalius bitterly commented on Valverde's plagiarism, accusing him of having performed very few dissections himself. Occasionally, however, Valverde corrected Vesalius' images, as in his depictions of the muscles of the eyes, nose, and larynx. One of Valverde's most striking original plates is that of a muscle figure holding his own skin in one hand and a knife in the other, which has been likened to Michelangelo's Saint Bartholomew in the Last Judgment section of the Sistine Chapel.
The original illustrations were most likely drawn by Gaspar Becerra (1520?-1568?), a contemporary of Michelangelo, and the copperplate engravings are thought to have been carried out by Nicolas Beatrizet (1507?-1570?), whose initials "NB" appear on several of the plates.
The images scanned for Historical Anatomies on the Web are from NLM's Italian edition printed in Rome in 1560. The Library's first edition printed in Rome, 1556, has deep-seated dirt on many of the plates, which would have produced lower quality images for the project.
Choulant, L. History and bibliography of anatomic illustration. Trans. and annotated by Mortimer Frank. (New York: Hafner, 1962), pp. 205-208.
Cushing, Harvey. A Bio-Bibliography of Andreas Vesalius. (New York: Schuman's, 1943), pp. 146-148.