TY - JOUR
T1 - Neogene paleobiogeography and East African paleoenvironments
T2 - Contributions from the Tugen Hills rodents and lagomorphs
AU - Winkler, Alisa J.
N1 - Funding Information:
Financial support for this research was generously provided by the Institute for the Study of Earth and Man, the Dedman College Graduate Student Assembly, and the Department of Geological Sciences, Southern Methodist University. Funding was also provided by the Geological Society of America and Sigma XI. Collection study grants were courtesy of the Smithsonian Institution, Washington, DC, and the American Museum of Natural History, New York. Some of the collecting was conducted by the Baringo Paleontological Research Project (BPRP). [That project is based at Yale University, and carried out in collaboration with the National Museums of Kenya. BPRP operates under a research permit issued by the Government of the Republic of Kenya (Permit OP/13/001/C 1391/ issued to Andrew Hill) and with permission to excavate from the Minister for Home Affairs and National Heritage. BPRP has been supported by grants to Andrew Hill from NSF (most recently SBR-9208903), the Louise H. and David S. Ingalls Foundation, the Louise Brown Foundation, Clayton Stephenson, and Yale University.] I thank the Government of the Republic of Kenya for research permission and the staff (in particular K. Cheboi) of the National Museums of Kenya for their help. This study was in partial fulfillment for a Doctorate in Philosophy in Geology at Southern Methodist University, Dallas, Texas, under the supervision of L. L. Jacobs. Andrew Hill, L. L. Jacobs, P. Andrews, and two anonymous individuals kindly reviewed drafts of this manuscript. I thank B. Barnes for preparing Figure 1.
PY - 2002
Y1 - 2002
N2 - A minimum of 28 genera of rodents and one genus of lagomorph were recovered from the Tugen Hills, Baringo District, Kenya, from localities dating from over 152.5 to about 4·4 Ma. The middle Miocene (sites dated between 15·8 and 15·3 Ma) rodent fauna recovered primarily from the Kipsaramon site complex, Muruyur Formation, includes a mixture of characteristically early Miocene taxa, and more derived forms. Composition of the African rodent fauna changes dramatically with the introduction of myocricetodontines, democricetodontines, and dendromurines, immigrants primarily from southern Asia. In the Tugen Hills, these taxa are first found in the Kabasero localities, Ngorora Formation, at sites dating from 12·5-12·33 Ma. A second major change in the African rodent fauna reflects the introduction of murines, immigrants from southern Asia. In the Tugen Hills murines are first encountered at Kapcheberek, Lukeino Formation, dated to 5·9-5·7 Ma. One rodent genus from the Lukeino Formation (Arvicanthis), and two from the Tabarin locality, Chemeron Formation (Heliosciurus, Paraxerus; 4·5-4·4 Ma), represent the earliest records of these extant African genera. A cricetomyine from the Ngorora Formation (12·5 Ma) is likely the earliest report of this exclusively African group. One of the earliest African records of porcupines (Hystricide) is from the Lukeino Formation. Lagomorphs are poorly represented, but include one of the earliest African occurrences of the family Leporidae from the Mpesida Beds (bracketed by dates of 7-6·2 Ma), and possibly a new genus of leporid from the Kapcheberek locality. Analysis of the Tugen Hills small mammals in association with other African records suggests several episodes of dispersal between Africa and Eurasia during the middle and late Miocene. Rodents from Kipsaramon are indicative of forests in conjunction with more open habitats. Those from the Kapcheberek locality are suggestive of a savanna habitat. The rodents from the Tabarin locality suggest a woodland environment.
AB - A minimum of 28 genera of rodents and one genus of lagomorph were recovered from the Tugen Hills, Baringo District, Kenya, from localities dating from over 152.5 to about 4·4 Ma. The middle Miocene (sites dated between 15·8 and 15·3 Ma) rodent fauna recovered primarily from the Kipsaramon site complex, Muruyur Formation, includes a mixture of characteristically early Miocene taxa, and more derived forms. Composition of the African rodent fauna changes dramatically with the introduction of myocricetodontines, democricetodontines, and dendromurines, immigrants primarily from southern Asia. In the Tugen Hills, these taxa are first found in the Kabasero localities, Ngorora Formation, at sites dating from 12·5-12·33 Ma. A second major change in the African rodent fauna reflects the introduction of murines, immigrants from southern Asia. In the Tugen Hills murines are first encountered at Kapcheberek, Lukeino Formation, dated to 5·9-5·7 Ma. One rodent genus from the Lukeino Formation (Arvicanthis), and two from the Tabarin locality, Chemeron Formation (Heliosciurus, Paraxerus; 4·5-4·4 Ma), represent the earliest records of these extant African genera. A cricetomyine from the Ngorora Formation (12·5 Ma) is likely the earliest report of this exclusively African group. One of the earliest African records of porcupines (Hystricide) is from the Lukeino Formation. Lagomorphs are poorly represented, but include one of the earliest African occurrences of the family Leporidae from the Mpesida Beds (bracketed by dates of 7-6·2 Ma), and possibly a new genus of leporid from the Kapcheberek locality. Analysis of the Tugen Hills small mammals in association with other African records suggests several episodes of dispersal between Africa and Eurasia during the middle and late Miocene. Rodents from Kipsaramon are indicative of forests in conjunction with more open habitats. Those from the Kapcheberek locality are suggestive of a savanna habitat. The rodents from the Tabarin locality suggest a woodland environment.
KW - Lagomorphs
KW - Miocene
KW - Paleobiogeography
KW - Paleoenvironments
KW - Pliocene
KW - Rodents
KW - Small mammals
KW - Tugen hills
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U2 - 10.1006/jhev.2001.0501
DO - 10.1006/jhev.2001.0501
M3 - Article
C2 - 11795976
AN - SCOPUS:0036008028
SN - 0047-2484
VL - 42
SP - 237
EP - 256
JO - Journal of Human Evolution
JF - Journal of Human Evolution
IS - 1-2
ER -