Fossil Shark Egg Casing (Palaeoxyris prendeli) - DLD 4132 cb4dd9096afc563d5d1b89ac6b2d535b octahedral or dodecahedral crystals

octahedral or dodecahedral crystals

Turquoise was originally imported from Turkey

rhaeticite and cyanite

Rhodochrosite (whose name means rose-colored) is commonly found in the form of stalactites and stalagmites in Argentina

more flexible arms that they wiggled in order to move around the sea floor

Fossil Shark Egg Casing (Palaeoxyris prendeli) - DLD 4132 cb4dd9096afc563d5d1b89ac6b2d535b octahedral or dodecahedral crystalsPalaeoxyris sp. and other shark egg cases were discovered roughly 175 years ago and because of their association with plants material in Mazon Creek concretions they were initially classified as plants. Not all researchers agreed, and only years later was the relationship with modern forms of spiral shark egg capsules established. These long, narrow, spindle shaped fossils have surfaces marked by weak spiral lines in a helix. At least 9 species of