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Alexander Stößel

Alexander Stößel

I am a post-doc in the Department of Human Evolution at the Max-Planck-Institute for Evolutionary Anthropology. I have a background in vertebrate morphology (esp. mammals and birds) and I am particularly interested in the evolutionary morphology of the mammalian cranium and its relevance for taxonomic and functional studies.


Morphology, Evolution and taxonomic implication of the mammalian cranium


Comparative and functional morphology of the bony labyrinth

I’m working directly with Fred Spoor, Philipp Gunz  and Romain David on the morphology of the bony labyrinth of hominins and other primate and mammalian species. The bony labyrinth is located in the petrous part of the temporal bone and houses the cochlea as the organ of hearing and the vestibule and semicircular canals for the perception of spatial orientation and movement. Since there is a functional link between semicircular canal shape and locomotion, studying the bony labyrinth offers the chance to learn more about the bipedal locomotor behaviour of extinct hominins, but also of a whole range of other mammalian locomotor adaptations. Further interest in this part of the cranium is due to its relevance for taxonomic distinctions between hominin species. We are investigating the bony labyrinth by using microCT data, 3D image processing and geometric morphometrics using 3D landmarks.

Left: Skull of a common chimpanzee (Pan troglodytes) and the same skull made transparent in order show position of bony labyrinth
Right: Illustration of landmark and semilandmarks introduced by Gunz et al. (2012) used in geometric morphometric analysis of bony labyrinth


Morphology and Evolution of Ear Ossicles

In a related project I’m studying the smallest bones of the mammalian body – the ossicles (malleus, incus, and stapes) of the middle ear. Based on microCT and by applying geometric morphometrics I’m interested in the morphological diversity of these tiny bones within the Hominidae and what the sparse hominin fossil record can tell us about the evolution of the middle ear and, consequently, of the sense of hearing. 

Ossicular ChainEar
Left: The three ear ossicles are the smallest bones of the mammalian body.
Right: Segmentation of tympanic membrane, ossicular chain and bony labyrinth of common chimpanzee


Morphology and taxonomic significance of mammalian nasal region

A third topic of interest is the comparative anatomy of the mammalian nose. I am studying evolutionary changes in the light of the relatively recently established molecular phylogeny of mammals and I am focusing on the taxonomic relevance of this region, particularly in afrotherian mammals.  

Stoessel, A. (Stößel), Junold, A. and Fischer, M.S. (2010).
The morphology of the eutherian ethmoidal region and its implications for higher-order phylogeny.
Journal of Zoological Systematics and Evolutionary Research, 48: 167-180.


Functional morphology of the avian hindlimb


Before coming to the MPI-EVA I did my PhD at the Friedrich-Schiller-Universität Jena on the evolution and functional morphology of the locomotor system of tetrapods. For my PhD thesis I investigated bipedal locomotion of birds and the morphology and evolution of the avian hindlimb. I used an experimental approach by applying biplanar high-speed x-ray videography in order to visualize and analyze the behavior of hindlimb elements and joints during bipedal locomotion (intralimb kinematics) of three bird species. Further analyses focused on avian limb proportions.

Stoessel, A. and Fischer, M.S. (2012)
Comparative intralimb coordination in avian bipedal locomotion.
The Journal of Experimental Biology, 215: 4055-4069.


Stoessel, A., Kilbourne, B. M. and Fischer, M. S. (2013).
Morphological integration versus ecological plasticity in the avian pelvic limb skeleton.
Journal of Morphology, 274: 483–495.


Department of Human Evolution
Max Planck Institute for Evolutionary Anthropology
Deutscher Platz 6
D-04103 Leipzig

phone: 0049 (0) 341 3550 365
fax: 0049 (0) 341 3550 399