Related Experiment Video
Updated: Jan 5, 2026

A Method to Make a Craniotomy on the Ventral Skull of Neonate Rodents
Published on: May 22, 2014
Basicranial ontogeny comparison in Pan troglodytes and Homo sapiens and its use for developmental stage definition of
Tommaso Mori1, Katerina Harvati1,2
1Palaeoanthropology, Senckenberg Centre for Human Evolution and Palaeoenvironment, Eberhard Karls Universität Tübingen, Tübingen, Germany.
Objective:
This study aims to develop a comparative basis for assessing the developmental stage of KNM-ER 42700 based on the ontogenetic pattern of the ectocranial surface of the basicranium in modern humans and chimpanzees.
Materials And Methods:
A total of 33 landmarks were collected from an ontogenetic sample of modern humans (80), chimpanzees (51), and 12 individuals classified as Homo erectus s.l. Ontogenetic trajectories were analyzed, and common aspects were extracted for the purpose of discriminating age groups. A regression of size on the extracted shape variables was used to investigate common ontogenetic allometry.
Results:
The basicranial development of chimpanzees and humans follows different trajectories; however, similarities are also present. The common shape component of development extracted can be used to define age groups in both chimpanzees and modern humans. The extracted shape component presents a similar ontogenetic and static-allometric pattern in these two species. The developmental stages of H. erectus s.l. specimens were attributed following these common traits. Our analysis correctly assigned developmental stages to those specimens of H. erectus for which developmental ages are known.
Discussion:
The component used for assessing the developmental stage has an ontogenetic allometric component. However, this shape component can discriminate age group irrespective of size and is no longer related to size when static allometry is considered. Adult H. erectus s.l. specimens were attributed to the adult category. KNM-WT 15000 fell with the late juvenile age group, whereas D2700 plotted in the region of overlap between the juvenile and adult age groups and Mojokerto with the younger age groups, as predicted by their known developmental ages. KNM-ER 42700 fell within the adult variability despite its incompletely fused spheno-occipital synchondrosis.
Related Concept Videos
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...
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...
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,...
Cranial Bones: Lateral View
The temporal bone forms the lower lateral side of the skull. The temporal bone is subdivided into several regions. The flattened upper portion is the squamous portion of the temporal bone. Below this area and projecting anteriorly is the zygomatic process of the temporal bone, which forms the posterior portion of the zygomatic arch. Posteriorly is the mastoid portion of the temporal bone. Projecting...

