Related Experiment Video
Updated: Jul 6, 2026

Reverse Dissection and DiceCT Reveal Otherwise Hidden Data in the Evolution of the Primate Face
Published on: January 7, 2019
The facial skeleton of the chimpanzee-human last common ancestor
1Functional Morphology and Evolution Unit, Hull York Medical School, The University of Hull, Hull, UK. sam.cobb@hyms.ac.uk
Abstract:
This review uses the current morphological evidence to evaluate the facial morphology of the hypothetical last common ancestor (LCA) of the chimpanzee/bonobo (panin) and human (hominin) lineages. Some of the problems involved in reconstructing ancestral morphologies so close to the formation of a lineage are discussed. These include the prevalence of homoplasy and poor phylogenetic resolution due to a lack of defining derived features. Consequently the list of hypothetical features expected in the face of the LCA is very limited beyond its hypothesized similarity to extant Pan. It is not possible to determine with any confidence whether the facial morphology of any of the current candidate LCA taxa (Ardipithecus kadabba, Ardipithecus ramidus, Orrorin tugenensis and Sahelanthropus tchadensis) is representative of the LCA, or a stem hominin, or a stem panin or, in some cases, a hominid predating the emergence of the hominin lineage. The major evolutionary trends in the hominin lineage subsequent to the LCA are discussed in relation to the dental arcade and dentition, subnasal morphology and the size, position and prognathism of the facial skeleton.
Related Concept Videos
Synteny and Evolution
Around 80 million years ago, the human and mice lineages diverged from the common ancestor. During the course of evolution, the ancestral chromosome underwent...
Overview of the Skull
The cranial vault surrounds and protects the brain and houses the middle and inner ear structures. This cavity is bounded superiorly by the rounded top of the skull, which...
Cranial Bones: Superior and Posterior View
The frontal bone is the single bone that forms the forehead. At its anterior midline, between the eyebrows, there is a slight depression called the glabella. The frontal bone also forms the supraorbital margin of the orbit. Near the middle of this margin is the supraorbital foramen, the opening that provides passage for a sensory nerve to the forehead. The frontal bone is thickened just above each supraorbital margin,...
Sutures of the Skull
Sutures are immobile joints between adjacent bones of the skull. The narrow gap between the bones is filled with dense, fibrous connective tissue that unites the bones. The long sutures located between the skull bones are not straight but instead follow irregular, tightly twisting paths. These twisting lines tightly...
Phylogeny
Muscles for Facial Expressions

