Skeletal taphonomy of the water frogs (Amphibia: Anura) from the Pit 7/8 of the Pliocene Camp dels Ninots site (Caldes de Malavella, NE Spain)

The Pliocene lacustrine infill of Camp dels Ninots maar (Girona, Spain) hosts an exceptional record of complete articulated skeletons. Here we present the taphonomical description of 22 fossil water frogs recovered from the Pit 7/8 of Can Argilera Sector. Description of their skeletal taphonomy is done on the basis of their distribution, completeness, articulation and limb position, and by establishing comparisons with the late Miocene site of Libros (Spain). Microscopic examination shows no evidence of digestion and absence of weathering. Mass mortality or any environmental stress-induced factors cannot be ruled out, but natural death seems to be the most probable. Limited time of decay prior burial seems to be the main pattern explaining the relatively high degree of articulation and completeness. Floatation is not to be disregard for some more (proximally) disarticulated specimens. Taphonomical patterns document two types of sub-environments inside a cool and deep lake, suggesting a more complex depositional scenario for Camp dels Ninots than the ones described in others similar Konservat-Lagerstatten.