original question: what organism classification whose earliest fossil record is a geologic time period during which [Santana Formation] is formed?
answer: melanopsis
answer type: Organism Classification.
auxiliary information: The Santana Formation is a geologic Lagerst√§tte in northeastern Brazil's Araripe Basin where the states of Pernambuco, Piau√≠ and Cear√° come together. The geological formation, named after the village of Santana do Cariri, lies at the base of the Araripe Plateau. It was discovered by Johann Baptist von Spix in 1819. The strata were laid down during the early Cretaceous, specifically during the early Cenomanian, about 92 million years ago, in a shallow inland sea. At that time, the South Atlantic was opening up in a long narrow shallow sea. The Santana Formation earns the designation of Lagerst√§tte due to an exceedingly well preserved and diverse fossil faunal assemblage. Some 25 species of fossil fishes are often found with stomach contents preserved, enabling paleontologists to study predator-prey relationships in this ecosystem. There are also fine examples of pterosaurs, reptiles and amphibians, invertebrates, and plants. Even dinosaurs are represented: a new maniraptor was described in 1996. The unusual taphonomy of the site resulted in limestone accretions that formed nodules around dead organisms, preserving even soft parts of their anatomy.
What is the classification of organism whose earliest fossil record belongs to a geologic time period in which [Santana Formation] was formed?