Faunal evidence for a late quaternary trans‐Antarctic seaway

摘要: Collapse of the West Antarctic Ice Sheet (WAIS) would raise global sea level by similar to 3.3-5 m. Ice-sheet models and geological data suggest at least one collapse has happened during last 1.1 Ma, some scenarios future climate change predict a within next two centuries. A complete WAIS open shallow seaways across Antarctica, potentially enabling exchange animals between seas. We investigated biological evidence for past connectivity different regions Antarctica comparing composition modern bryozoan assemblages from continental margin around Antarctica. Surprisingly, we found most similarity areas which are not currently connected - shelves Weddell Sea (WS) Ross (RS). evaluated three hypotheses explain this conclude that bryozoans likely dispersed through trans-Antarctic seaway opened in response WS RS shelves. These must have survived glaciations(s) subsequent ice ages refuges, whereas they were wiped out other shelf. After glacial period, could freely disperse many examined (e.g. Peninsula South Shetland Islands), allowed recolonization had been eradicated age. For on be more than those close proximity means may as late few interglacials. Current rates warming exceptional compared with near cycles so our study, strongest faunal recent past, thus supports predictions (with considerable implications) resultant major exchanges.