Pucapampella

Pucapampella rodrigae was described in 1986 by paleontologists Philippe Janvier and Mario Suárez-Riglos, based on three isolated skull fragments discovered in Bolivia. These remains are preserved in concretions and were initially identified as being from the Middle Devonian (Givetian stage) Sica Sica Formation and Huamampampa Formation, although they were not discovered in situ and are now thought to have originated from the older Early Devonian (Emsian stage) Belén Formation. A number of additional isolated skull fragments and a relatively complete braincase have subsequently been identified from Bolivia, including material from the Icla Formation. Later fossils discovered in phosphate nodules from the Chagrapi Formation of the Department of Puno, Peru have also been assigned to Pucapampella. An articulated skull and jaws from the Emsian-stage Gydo Formation of South Africa was described in 2001 and also tentatively assigned to the genus, although this specimen has since been reassigned to Gydoselache. The genus name honors the village of Pucapampa where the holotype specimen originated, and the species name, P. rodrigae, honors Gabriela Rodrigo who discovered the specimen. == Description ==

, Peru. Scale bar = 0.5 cm The cranium was divided into two unfused, transversely-aligned segments by a cranial fissure, another feature unique among cartilaginous fishes. Because these remains show no indication of tessellated cartilage, it has been questioned if they originated from a chondrichthyan at all. == Classification ==

When first described, Pucapampella was thought to be a possible member of the Bradyodonti (an assemblage of early chimaera relatives).While only P. rodrigae has been named, it has been proposed that multiple species of Pucapampella are actually known due to the differences between specimens. == Paleobiology ==

Researchers Alexander Kuznetsov and Nadezhda Kryukova have suggested the genus fed by using a "backwards-ripping" motion, where backwards movement of the body would be used to pull chunks of flesh from prey. This behavior is in contrast to most living sharks which tear off chunks of flesh with side-to-side motions of the head, but is similar to the feeding method of living Sharpnose sevengill sharks. This behavior would be allowed by the musculature of the head. == Paleoecology ==

During the Emsian stage, Bolivia and Peru were part of the Malvinokaffric Realm; a region which existed during the Late Silurian and Early Devonian, is characterized by a unique fauna, was made up of portions present-day Antarctica, South America, and Africa, and which sat near the South Pole. In contrast to other regions at that time placoderms were largely absent, with the exception of Bolivosteus. It is likely that the rocks containing Pucapampella were deposited in anoxic, deep-water environments. == See also ==