Late Cretaceous palaeoenvironments and biotas: an Antarctic perspective

• Published in: Antarctic Science
• Main Author: Crame, J.A.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Cambridge University Press 1992
• Subjects: Antarctic; The Antarctic; Antarctic Peninsula; Austral; Ross Island; New Zealand; Antarc*; Antarctic Science; Antarctica; James Ross Island
• Online Access: http://nora.nerc.ac.uk/id/eprint/518384/; https://doi.org/10.1017/S0954102092000555

The Cretaceous period is often regarded as one of "greenhouse" warmth, with perhaps its acme occurring in the late Albian stage (100 Ma ago). However, it is now apparent that, even at this time, there were significant meridional temperature gradients and distinct temperate biotas in the highest latitude regions. This is particularly so in the Southern Hemisphere, where an extensive Albian fossil record from Antarctica, Australia and New Zealand has revealed the presence of austral floras and faunas. With the recent improvements in stratigraphical correlations, it has become possible to trace the later Cretaceous palaeoenvironmental record in the Antarctic Peninsula region. Unfortunately, resolution of the early Late Cretaceous (Cenomanian–Coniacian stages) is still imprecise; there are some indications of strongly differentiated palynological assemblages, but studies of both macrofaunas and palaeotemperature estimates are incomplete. By the Santonian–Campanian, high-latitude biotas are well developed in the James Ross Island region and their enhancement through the final stages of the Cretaceous can be linked to a phase of global cooling. The persistence of low diversity temperate communities in high latitude regions may be of considerable ecological and evolutionary significance. For example, there is evidence to suggest that these communities may have been more resistant to mass extinction events; they may also have been important source regions for replacement taxa that arose after such events.