How to translate text using browser tools
13 September 2023 NOT ENTIRELY ICHTHYOSAUR: A MYSTERIOUS LAMNIFORM AND ICHTHYOPTERYGIAN-FALL ASSOCIATION FROM THE ABYSSAL UPPER CRETACEOUS OF THE NORTHERN APENNINES (ITALY)
Giovanni Serafini, Jacopo Amalfitano, Silvia Danise, Erin E. Maxwell, Riccardo Rondelli, Cesare A. Papazzoni
Author Affiliations +
Abstract

Axial remains of a large ichthyosaur and a medium-sized anacoracid shark from the deep-water sediments of the Cenomanian of the Northern Apennines (Northern Italy) are described in detail. The specimens were found closely associated (less than 0.3 m apart), and offer an invaluable window into the taphonomy and dead-fall stages of pelagic vertebrates in a Mesozoic abyssal plain. The anacoracid shark remains, initially misinterpreted as an ichthyosaur, consist of eight articulated vertebrae embedded in a block of dark arenaceous matrix, and represent the first occurrence of an articulated shark from the Northern Apennines. The ichthyosaur remains consist of seven discoidal vertebrae and several unidentified fragments. Due to the absence of diagnostic skeletal elements, both specimens are assigned only at higher taxonomic levels. The two fossils, which come from the same outcrop and possibly from the same stratigraphic horizon, share a common taphonomic history, in terms of both their preservation and diagenesis. Mineralogy of the matrices of both is dominated by manganese micro-nodules, consistent with the deposition of polymetallic nodules in bathyal-abyssal settings. Biostratinomic processes that impacted the two specimens also provide insight on the development of Mesozoic marine vertebrate-falls in the deep-sea. Localized pyrite framboids inside the bone spongiosa are possible evidence of the sulfophilic stage (microbially mediated sulfur mobilization during lipid decay) in the ichthyosaur fall. Burrows assigned to Taenidium on the surface of the shark block, interpreted as worm-like feeding burrows or arthropod locomotion and feeding trails, might represent evidence of the enrichment opportunistic stage. Although intriguing, we have no evidence to support the hypothesis that this peculiar association of two pelagic predators is due to ecological interaction between the two animals.

Giovanni Serafini, Jacopo Amalfitano, Silvia Danise, Erin E. Maxwell, Riccardo Rondelli, and Cesare A. Papazzoni "NOT ENTIRELY ICHTHYOSAUR: A MYSTERIOUS LAMNIFORM AND ICHTHYOPTERYGIAN-FALL ASSOCIATION FROM THE ABYSSAL UPPER CRETACEOUS OF THE NORTHERN APENNINES (ITALY)," PALAIOS 38(8), 331-344, (13 September 2023). https://doi.org/10.2110/palo.2022.054
Received: 8 November 2022; Accepted: 29 June 2023; Published: 13 September 2023
JOURNAL ARTICLE
14 PAGES

This article is only available to subscribers.
It is not available for individual sale.
+ SAVE TO MY LIBRARY

RIGHTS & PERMISSIONS
Get copyright permission
Back to Top