The imagery on this page is the basis for a paper entitled Digital Cranial Endocast of Pucadelphys andinus, a Paleocene Metatherian, by T. E. Macrini, C. de Muizon, R. L. Cifelli, and T. Rowe (2007, Journal of Vertebrate Paleontology 27:99-107). The abstract is as follows:

       A digital cranial endocast of Pucadelphys andinus, a Paleocene metatherian from Bolivia, is        described. This is the first cranial endocast described for the taxon and the only one (to date) from a        stem marsupial (i.e., non-marsupial metatherian). The Pucadelphys endocast is compared with others        generated from skulls from six taxa of extant marsupials (Monodelphis domestica, Didelphis virginiana,        Dasyurus hallucatus, Vombatus ursinus, Phascolarctos cinereus, and Dromiciops australis). The        Pucadelphys endocast is generally similar to the didelphid marsupial Monodelphis. However, the        olfactory bulb casts and the cerebellar space (approximated using vermis cast length) of Pucadelphys        are relatively large in comparison to those of these extant marsupials. The cerebral hemisphere casts        of Pucadelphys are dorsoventrally thin in comparison to those of the extant marsupials examined        here. With other dimensions of the cerebral hemisphere casts being comparable between        Pucadelphys and the extant marsupials, this suggests that the overall volume of the cerebral        hemispheres was smaller in Pucadelphys. Thus, two possible synapomorphies for crown Marsupialia are        a decrease in size of the cerebellar space and an increase in cerebral hemisphere volume.

This specimen was collected from a site called "the Quarry" in the lower Paleocene Santa Lucia Formation at Tiupampa, Mizque Province, Department of Cochabamba, south-central Bolivia. It was made available to the University of Texas High-Resolution X-ray CT Facility for scanning by Drs. Christian de Muizon of the Muséum national d'Histoire naturelle (Paris) and Richard Cifelli of The University of Oklahoma. Funding for scanning was provided by Dr. Timothy Rowe of The University of Texas at Austin.

The specimen was scanned by Richard Ketcham in the spring of 1997 along the horizontal axis for a total of 115 512x512 pixel slices. Each slice is 0.10 mm thick, with an interslice spacing of 0.10 mm and a field of reconstruction of 35.1 mm.

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Click on the thumbnail to the left for a pitch animation (1.9 mb) of the Pucadelphys cranial endocast highlighted in red within the skull, which is rendered semi-transparent.

Click on the thumbnail to the left for a pitch animation (1.5 mb) of the isolated Pucadelphys cranial endocast.

Click on the thumbnail to the left for a roll animation (2.2 mb) of the Pucadelphys cranial endocast highlighted in red within the skull, which is rendered semi-transparent.

Click on the thumbnail to the left for a roll animation (1.9 mb) of the isolated Pucadelphys cranial endocast.