The Africa–Madagascar connection and mammalian migrations

Madagascar separated from Africa in the Middle–Late Jurassic and has been in its present position relative to Africa since the Early Cretaceous (∼120–130 my). Several Early Eocene to Late Oligocene (∼50–26 my) terrestrial mammalian groups are observed on Madagascar that have a similar ancestral lineage to those found in Africa. These mammalian groups means of transport across the Mozambique Channel from Africa to Madagascar was either by traversing on exposed land masses across a land bridge or by swimming/rafting, since (1) Madagascar has been separated from mainland Africa for at least 70 my before their arrival, and (2) it is unlikely that similar ancestral lineage’s evolved simultaneously in separated regions. No evidence has been found for a land bridge across the Mozambique Channel. The mammals thus either swam or have been swept away on vegetation mats from rivers flowing out of Mozambique or Tanzania.