Dinosaur bonebed amber from an original swamp forest soil

Abstract

Dinosaur bonebeds with amber content, yet scarce, offer a superior wealth and quality of data on ancient terrestrial ecosystems. However, the preserved palaeodiversity and/or taphonomic characteristics of these exceptional localities had hitherto limited their palaeobiological potential. Here we describe the amber from the Lower Cretaceous dinosaur bonebed of Arino (Teruel, Spain) using a multidisciplinary approach. Amber is found in both a root layer with amber strictly in situ and a litter layer namely composed of aerial pieces unusually rich in bioinclusions, encompassing 11 insect orders, arachnids, and a few plant and vertebrate remains, including a feather. Additional palaeontological data - charophytes, palynomorphs, ostracods- are provided. Arino arguably represents the most prolific and palaeobiologically diverse locality in which fossiliferous amber and a dinosaur bonebed have been found in association, and the only one known where the vast majority of the palaeontological assemblage suffered no or low-grade pre-burial transport. That has enabled unlocking unprecedentedly complete and reliable palaeoecological data out of two complementary windows of preservation from the same site.