Ambergris cololites of Pleistocene sperm whales from central Italy and description of the new ichnogenus and ichnospecies Ambergrisichnus alleronae

Ambergrisichnus alleronae igen. et isp. nov. from early Pleistocene clay marine deposits of Umbria, central Italy is here described, and attributed to cololites (evisceralites) of sperm whales. This interpretation is supported by the following characteristics that are frequently identified in modern ambergris including: internal organization of concentric structures, external shape with converging striae and bulges (rognons), and inclusions of squid beaks. These cololites were deposited in a relatively deep (100-150 m) marine environment, and the large number of structures in a restricted area is plausibly ascribed to multiple death events of sperm whales. The description of A. alleronae igen. et isp. nov. is held by analysis of the taphonomic processes that took place after the sperm whale carcasses reached the seabed and led to fossilization. The analysis of benthic micro- and macrofauna found close to the studied structures provides supplementary data, which support the reconstruction of palaeoecological and palaeoenvironmental conditions comparable with those of the whale fall communities. This work increases knowledge of vertebrate coprolites. Moreover, this new information provides the data about the frequency of sperm whales in the Tyrrhenian Sea during the early Pleistocene, and raises new questions about the causes of this anomalous accumulation.