Pygites brachiopods… or bizarre fossil scrotal phylogeny?
Images 1 and 2: Source. In German.
Image 3: Source
Caption: “Pygites is unusual for a Terebratulid brachiopod. It shares many of the same features that other brachiopods in it’s order except that it has a hole in the middle of it. The hole is created as the shell grows and splits into lobes that then eventually meet back together and enclose a hollow area. This is odd behavior for a brachiopodand I’ve only seen a handful of genera that have even exaggerated lobes, such as Dicoelosia from the Haragan formation, let alone those that surround a hole. Below are three specimens from the Cretaceous (Hauterivian stage) of Spain that show you the variation in the genera.”
Image 4: ”Pygites diphyoides (d’Orbigny, 1849) from the Hauterivian (Lower Cretaceous) of Cehegin, Murcia, Spain. This terebratulid is characterized by a central perforation through its valves.” Source: Wikipedia; cc-by-sa
Image 5: Pygites diphyoides (source)