Single Object 1: https://commons.wikimedia.org/wiki/File:Ammonite_fossil.jpg
Single Object 2: https://commons.wikimedia.org/wiki/File:Cheirurus_ingricus_-_trilobite_-_Smithsonian_Museum_of_Natural_History_-_2012-05-17.jpg
Flat Surface (more or less): https://commons.wikimedia.org/wiki/File:Intersecting_Dikes_in_Black_Canyon_of_the_Gunnison.jpg
Complex Subject: below…