Bioerosion structures in a Late Cretaceous mosasaur from Antarctica

Abstract

Bioerosive structures in the cortical region of a vertebra from a mosasaur fall in the López de Bertodano Formation (Upper Maastrichtian) in Seymour Island (Isla Marambio), Antarctica, are reported. The traces studied are similar but not coincident with the described microborings in other fossil bone remains. The morphology and extension of these bioerosive structures are considered as the result of the activity of endolithic organisms on the original vascular channels of the bone. They are approximately straight, anastomosed, and commonly filled with an opaque mineral and framboidal pyrite. As most of the bone structure is well preserved, only the small portion of the cortical region was exposed to the microorganisms' activity. This would mean that the mosasaur individual died well earlier than the burial event. This is their first report of this type of bioerosive structures in a mosasaur fall. Keywords Bioerosive structures • Marine reptile • Cretaceous • AntarcticaThis article is part of a Topical Collection in Facies on Bioerosion: An interdisciplinary approach, guest edited by Max Wisshak et al.

Biodeterioration of Antarctic fossil penguin bones caused by lichens from the Eocene La Meseta Formation

“…The sulfur associated with fossil bones crystallizes as pyrite under anoxic or suboxic conditions (Canfield 1991;Pfretzschner 2001), creating a hostile environment for aerobic organisms. In other cases, when sulfur appears as crystals of cubic pyrite, it has been attributed to the bacterial activity during the early stages of the decay processes (for example Talevi and Brezina 2019). Besides, the presence of sulfur generates acid in the substrate, and is toxic for most lichens at high concentrations.…”

A Prognathodontin Mosasaur from the Maastrichtian of the Dakhla Oasis, Western Desert, Egypt

“…Early work on mosasaurs focused heavily on Europe and North America [2][3][4][5][6][7], where paleontology first began as a science. Later on, they were also documented in South America and Antarctica [8][9][10][11][12][13][14][15][16][17][18]. However, mosasaurs appear to have been particularly diverse in the tropics and subtropics [2], which have until recently been relatively poorly known.…”