Vintage ape skeleton drawing from an 1890 natural history work by Alfred Brehm (1829-1884). I found two versions of Brehm’s Life of Animals; the original in German and a later English translation. The two have many of the same illustrations. Some are better in one version; others are better in the second. Oddly enough, both discussed the differences between humans and the apes, but, it was only in the original German version which included this ape skeleton drawing and the human skeleton drawing it was compared to were included.
This image is copyright free and in the public domain anywhere that extends copyrights 70 years after death or at least 120 years after publication when the original illustrator is unknown.