Dr. Sherwood’s initial interest in craniofacial biology began with an interest in human evolution. The striking range of craniofacial morphologies in the hominin lineage, from the ape-like Australopithecus afarensis to the extreme adaptations in Australopithecus boisei, has inspired many researchers to seek answers to the endless array of questions regarding the myriad influences acting on the different components.
Much of his early work investigating evolutionary changes in craniofacial form focused on a component of the cranial base, the temporal bone. The temporal bone can be considered the most complex bone in the skull, as it has a unique ontogenetic history with at least five developmental units readily defined: squamous, tympanic, petromastoid, styloid and the bony labyrinth. It contains two major functional complexes, the masticatory and auditory apparatus, as well as relationships with the brain and local musculature. This complexity has made the temporal bone a useful tool in phylogenetic assessment of fossil hominins.
Part of Dr. Sherwood's interest in the temporal bone arose from his association with the Baringo Paleontological Research Project (BPRP) directed by Andrew Hill of Yale University. This project began investigating the Tugen Hills succession in the Lake Baringo area of Kenya in 1981, and Dr. Sherwood’s first trip to Baringo was in 1988. This region contains sedimentary units ranging from 200,000 to 16 million years old. Included in the fossil finds from this area is a partial temporal bone (known as the Chemeron Temporal) dated to 2.4 million years old.
Part of Dr. Sherwood’s dissertation research was to conduct comparative anatomical studies of the temporal bone of hominins and apes and to consider the taxonomic placement of the Chemeron Temporal. He agreed with earlier assessments (by Steve Ward and Andrew Hill) that the evidence supports placement of this specimen into the genus Homo, making this specimen the earliest fossil evidence for the genus that includes humans. Other interesting fossils from this area include the partial upper limb skeleton of Equatorius africanus, a ~15.5-million-year-old ape.
After working in the Baringo Basin for several years, Dr. Sherwood initiated an ill-fated fieldwork project of his own in the Lake Rukwa Basin of southeastern Tanzania. This region has produced tantalizing evidence of hominid occupation in the form of stone tools and interesting fossils have been found in Malawi adjacent to the Tanzanian border. Dr. Sherwood and his colleague, John Kingston, successfully obtained funding for the project from the National Science Foundation and the National Geographic Society and traveled to the region in 2001. Despite using state-of-the-art satellite imagery and numerous geologic reports of plio-pleistocene aged sediments, we found only one area with fossiliferous deposits (most likely mesozoic in age). Such luck is not unusual and demonstrates that, even with proper preparation, there is always an element of luck when searching for fossils. While this trip did not produce the fossils we had hoped for, we enjoyed our time in Tanzania, a spectacularly beautiful country.
In 2002, Dr. Sherwood became interested in exploring the genetic underpinnings of cranial variation. While this work has a strong biomedical component, it also has strong relevance to questions regarding the evolution of the primate skull and he continues to present and publish in this discipline.
Funding
- 2003-2004 Graduate School, U. Wisconsin. R.J. Sherwood, P.I. Origin of the Genus Homo.
- 2002-2003 Graduate School, U. Wisconsin. R.J. Sherwood, P.I. Survey of the Mbeya District, Tanzania.
- 2001-2002 National Geographic Society. R.J. Sherwood, P.I. J.D. Kingston, Co-P.I. Paleontological Survey of the Lake Rukwa Basin, Tanzania. #6977-01.
- 2001-2002 Graduate School, U. Wisconsin. R.J. Sherwood, P.I. Biogeographic Diversity of Early Hominins.
- 2000-2002 National Science Foundation. R.J. Sherwood, P.I., J.D. Kingston, Co-P.I. Paleontological Survey of the Lake Rukwa Basin, Tanzania. BCS-0080804.
- 2000-2002 Cleveland Museum of Natural History. R.J. Sherwood, P.I. Archiving and Database Management of CMNH Radiographic Collection.
- 2000-2001 Graduate School, U. Wisconsin. R.J. Sherwood, P.I. Paleontological Survey of the Lake Rukwa Basin, Tanzania.
- 1999-2000 Graduate School, U. Wisconsin. R.J. Sherwood, P.I. Comparative Basicranial Anatomy of Hominoids with Implications for Human Evolution.
- 1993-1994 The L.S.B. Leakey Foundation. R.J. Sherwood, P.I. Internal Morphology of the Temporal Bone of Hominoids. B-3103.
- 1992-1993 National Science Foundation, Dissertation Improvement Grant, Anthropology Program. Dr. S. Ward P.I., R.J. Sherwood co-P.I., The Hominid Temporal Bone: Ontogeny and Phylogenetic Implications. DBS-9208364.
- 1992-1993 University Fellowship, Kent State University.
- 1992 Summer Dissertation Fellowship, Kent State University.
