I just added the below entry and images to the Trombone History Timeline (16th century). Both are somewhat curious images that are likely to be an artist’s best attempt at a relatively new instrument (an instrument that is rather difficult to depict anyway).

1507—Augsburg, Germany: Erhart Öglin publishes Melopoeae sive Harmoniae tetracenticae super xxii genera carminum by Petrus Tritonius, an Austrian humanist and composer. Among the musical content are two different woodcuts depicting what appear to be trombone players. In the first, what is apparently a trombone is included among a band of minstrels (the group of musicians on the left). In the second plate, in which the nine muses surround Apollo, Jupiter, Minerva, and Mercury, an instrument with two bells, representing either a trumpet or a trombone (or perhaps both), is being played by the muse Urania (see below 4 images; public domain).