caption: The image shows four different types of oyster shells on a black background, with the text "Yoldiella folini waren, 1978, holotype usnm 199675" written on the right side. The shells are arranged in a symmetrical pattern, with each shell having a unique shape and texture. The colors of the shells range from light to dark, with some having a glossy finish and others having a matte finish. The text is written in a bold, white font, making it stand out against the dark background.