The fossil record of durophagous predation in the James Ross Basin over the last 125 million years
at : Feb 18, 2019 09:55:52  (view:102)

Authors: Elizabeth M. Harper1*, J. Alistair Crame2, Alice M Pullen1

1Department of Earth Sciences, Downing Street, Cambridge, CB2 3EQ, UK; 

2British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK

Corresponding author: Dr.Elizabeth M.Harper, emh21@cam.ac.uk

Abstract: We review the evidence for predation of shelly benthic prey over 125 million years of earth history in the James Ross Basin, Antarctica (~65°S).  Although poor in the Early Cretaceous lower parts of the sequence, which represent essentially deeper water facies, evidence for both potential crushers and drillers becomes more apparent in the Santonian – Campanian Santa Marta Formation, and by the Maastrichtian López de Bertodano Formation there is an extensive fossil record of drill holes attributable to naticid gastropods, and some evidence of crushing by decapods crustaceans and possibly other taxa too. This continues at a similar level of intensity across the K/Pg boundary into the Danian Sobral Formation, but is less well constrained in the latest Paleocene – Early Eocene.  The most extensive record of predation occurs in the Middle Eocene section of the La Meseta Formation on Seymour Island which also records the highest levels of benthic diversity within the entire basin. This key section is providing some important new evidence to suggest that the rate of acceleration of benthic predation intensity through the Late Mesozoic – Early Cenozoic in the polar regions may be similar to that seen in lower latitude regions. Predator – prey interaction was a key factor in the evolution of polar marine faunas too.

Keywords: drilling, crushing, molluscs, escalation, Seymour Island