Early anthropoid femora reveal divergent adaptive trajectories in catarrhine hind-limb evolution

• Published in: Nature communications Vol. 10; no. 1; pp. 4778 - 9
• Main Authors: Almécija, Sergio, Tallman, Melissa, Sallam, Hesham M., Fleagle, John G., Hammond, Ashley S., Seiffert, Erik R.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 08-11-2019; Nature Publishing Group; Nature Portfolio
• Subjects: 631/181/19/2471; 631/181/414; Animals; Apes; Biological Evolution; Cercopithecidae; Divergence; Evolution; Femur; Fossils; Hindlimb; Hip; Hip joint; Hominidae; Humanities and Social Sciences; Humans; Monkeys; Morphology; multidisciplinary; Oligocene; Paleontology; Phylogeny; Primates; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-019-12742-0

The divergence of crown catarrhines—i.e., the split of cercopithecoids (Old World monkeys) from hominoids (apes and humans)—is a poorly understood phase in our shared evolutionary history with other primates. The two groups differ in the anatomy of the hip joint, a pattern that has been linked to their locomotor strategies: relatively restricted motion in cercopithecoids vs. more eclectic movements in hominoids. Here we take advantage of the first well-preserved proximal femur of the early Oligocene stem catarrhine
Aegyptopithecus
to investigate the evolution of this anatomical region using 3D morphometric and phylogenetically-informed evolutionary analyses. Our analyses reveal that cercopithecoids and hominoids have undergone divergent evolutionary transformations of the proximal femur from a similar ancestral morphology that is not seen in any living anthropoid, but is preserved in
Aegyptopithecus
, stem platyrrhines, and stem cercopithecoids. These results highlight the relevance of fossil evidence for illuminating key adaptive shifts in primate evolution.
The proximal femur is key for understanding locomotion in primates. Here, the authors analyze the evolution of the proximal femur in catarrhines, including a new
Aegyptopithecus
fossil, and suggest that Old World monkeys and hominoids diverged from an ancestral state similar to
Aegyptopithecus
.