SÉMINAIRE / SEMINAR
6ème séance / 6th session: The Giant Horned Crocodiles that Ate our Ancestors, par/by Christopher A. BROCHU (University of Iowa)
Jeudi 9 juin 2016 (16-17h30) / Thursday 9 June 2016 (4:00 PM-5:30 PM). Lieu / Venue: Auditorium of the Authority for Research and Conservation of Cultural Heritage
Organisation: CFEE & Authority for Research and Conservation of the Cultural Heritage (Heritage Collection & Laboratory Service Directorate, Heritage Training Unit).
The Giant Horned Crocodiles that Ate our Ancestors, par/by Christopher A. BROCHU (University of Iowa)
Crocodiles and related animals have a rich fossil record in eastern Africa. They were long perceived as unchanging “living fossils,” but a far more complex history is coming into view. Crocodiles from the early to middle Miocene (11 to 23 million years ago) are unrelated to the Nile crocodile (Crocodylus niloticus) currently living in the region. Instead, they include relatives of the modern West African dwarf crocodile (Osteolaemus) and a South American group related to the modern Indian gharial (Gavialis). These lineages had disappeared by 7 million years ago, replaced by crocodiles related – but not ancestral – to C. niloticus. Some of these had horns and may have grown to a length of 7.5 m – larger than C. niloticus. As many as five species may have coexisted in eastern Africa at one time. There is much yet to be learned; at least ten unnamed species have been identified in museum collections, and many more may yet be found. These were the largest predators our ancestors faced, and yet there is still much to be learned about the group – many unnamed species have been found in museum collections, and several questions remain unanswered: when did the ancestors of the Nile crocodile appear in eastern Africa? Why did the kinds of crocodiles found the region change between 11 and 7 million years ago? Did these changes occur at the same time throughout eastern Africa? Why did crocodylian diversity drop? The answer to these questions lies will be found in museum collections and ongoing field work.
L’intervenant / The speaker
Christopher A. Brochu est professeur de paléontologie et directeur des Undergraduate Studies au sein du Département des sciences de la terre et de l’environnement de l’Université de l’Iowa. / Christopher A. Brochu is a Professor of Paleontology and Director of Undergraduate Studies in the Department of Earth and Environmental Sciences at the University of Iowa.