The Pliocene hominin diversity conundrum: Do more fossils mean less clarity?
Recent discoveries of multiple middle Pliocene hominins have raised the possibility that early hominins were as speciose as later hominins. However, debates continue to arise around the validity of most of these new taxa, largely based on poor preservation of holotype specimens, small sample size, or the lack of evidence for ecological diversity. A closer look at the currently available fossil evidence from Ethiopia, Kenya, and Chad indicate that Australopithecus afarensis was not the only hominin species during the middle Pliocene, and that there were other species clearly distinguishable from it by their locomotor adaptation and diet. Although there is no doubt that the presence of multiple species during the middle Pliocene opens new windows into our evolutionary past, it also complicates our understanding of early hominin taxonomy and phylogenetic relationships.
Department of Physical Anthropology, Cleveland Museum of Natural History, Cleveland, OH 44106; Departments of Anthropology, Anatomy, and Cognitive Sciences, Case Western Reserve University, Cleveland, OH 44106; yhaileselassie@cmnh.org.
Yohannes
Y
Haile-Selassie
Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, D-04103 Leipzig, Germany;
Stephanie M
SM
Melillo
Department of Paleobotany and Paleoecology, Cleveland Museum of Natural History, Cleveland, OH 44106.
Denise F
DF
Su
D000818:Animals; D005075:Biological Evolution; D002596:Chad; D005002:Ethiopia; D005580:Fossils; D015186:Hominidae / Q000145:classification*; D007630:Kenya; D010802:Phylogeny
Australopithecus; Kenyanthropus; Pliocene; ecological diversity; hominin diversity