New Pleistocene avian ichnosites on South Africa’s Cape south coast

Abstract

Twelve new avian ichnosites have been identified on South Africa’s Cape south coast, adding to the 29 sites previously identified. More than half of these 41 avian ichnosites are found along a 9-km stretch of coastline east of Still Bay. The new sites provide the first southern African trace fossil records of the dove, stork and heron families, as well as a possible ostrich trackway and evidence of probable ostrich eggshell fragments. They buttress the previous inference of large avian chronospecies during the Pleistocene. The preponderance of large- and mediumsized tracks can be attributed to a bias whereby fossil tracks of larger, heavier birds are easier to recognise and interpret. Four of the longest fossil avian trackways ever to be identified occur within a 350-m stretch of coastline in the Driefontein area, east of Still Bay. The new findings provide an enhanced picture of the Pleistocene avifauna of the region. Many of the new sites are fragile and have limited prospects to endure, emphasising the need to document them through photogrammetry, and to regularly explore the coastline in high-yield areas in search of further sites.