TY - JOUR
T1 - Fossil bird eggs from the Pliocene of Laetoli, Tanzania
T2 - Their taxonomic and paleoecological relationships
AU - Harrison, Terry
N1 - Funding Information:
I thank the following individuals for their participation in the expeditions to Laetoli that contributed to the recovery of the material discussed here: P. Abwalo, P. Andrews, E. Baker, M. Bamford, R. Chami, M. Duru, C. Feibel, Terri Harrison, S. Hixson, J. Kingston, K. Kovarovic, A. Kweka, M. Lilombero, M.L. Mbago, K. McNulty, C.P. Msuya, S. Odunga, C. Robinson, W.J. Sanders, L. Scott, and D. Su. I thank the Tanzania Commission for Science and Technology and the Unit of Antiquities in Dar es Salaam for permission to conduct research in Tanzania. Special thanks go to N. Kayombo (Director General), P. Msemwa (Director), F. Mangalu (Director) and all of the curators and staff at the National Museums of Tanzania in Dar es Salaam and Arusha for their support and assistance. The Government of Kenya and the National Museums of Kenya are thanked for permission to study the collections in Nairobi. For their advice, discussion, help and support I gratefully acknowledge the following individuals: P. Andrews, R. Blumenschine, D.M.K. Kamamba, O. Kileo, J. Kingston, K. Lasotumboyo, M.G. Leakey, S. Mataro, E. Mbua, G. Olle Moita, C.S. Msuya, M. Muungu, J. Pareso, C. Peters, M. Pickford, and B. Senut. I thank the reviewers, Yannicke Dauphin and James L. Hayward, for helpful comments and additional references. Fieldwork at Laetoli was supported by grants from National Geographic Society, the Leakey Foundation, and NSF (Grants BCS-9903434 and BCS-0309513).
PY - 2005/4
Y1 - 2005/4
N2 - Recent paleontological investigations at the Pliocene site of Laetoli and at neighboring localities on the Eyasi Plateau of northern Tanzania have led to the recovery of a sizable collection of fossil bird eggs. The material comes from the Upper Laetolil Beds, dated at ∼3.6-3.8 Ma, and the Lower Laetolil Beds, dated at 3.8 Ma to older than 4.3 Ma. The preservation of relatively complete eggs (other than those of ratites) is an extremely rare occurrence in the fossil record, and Laetoli is the only locality in Africa that has produced such well-preserved eggs. Deposition of carbonatite air-fall tuffs led to the rapid burial of the eggs sub-aerially, and they were then preserved in paleosols that were geochemically conducive to their preservation. The collection of fossil eggs from Laetoli can be assigned to at least five different species of ground-nesting birds, including two or three species of francolins, a species of guineafowl, and a larger bird of uncertain taxonomic status about the size of a bustard. Most of the eggs can be assigned to a large species of Francolinus, similar in size to the extant F. afer and F. leucoscepus. A smaller species of francolin, about the size of Francolinus coqui or F. sephaena, is also represented, but is less common. A single egg may represent an even smaller species of francolin, about the size of Francolinus lathami or F. nahani, but its attribution to Francolinus is less certain. The evidence of at least two species of Francolinus at Laetoli indicates that francolins were already taxonomically diverse in East Africa by the mid-Pliocene. Three eggs are similar in their overall dimensions and morphology to the living Numida meleagris, the helmeted guineafowl. An avian community including at least one small species of francolin, a larger francolin, and a guineafowl (as well as ostriches and a vulture) implies that the paleoecology at Laetoli was likely to have been open woodland, bushland, savanna or grassland. However, francolins and guineafowl generally require low brush and thickets for refuge, as well as trees to roost in at night, so they tend to prefer mosaic ecotonal habitats offering open feeding areas with good visibility, but with dense vegetation cover and patches of woodland nearby.
AB - Recent paleontological investigations at the Pliocene site of Laetoli and at neighboring localities on the Eyasi Plateau of northern Tanzania have led to the recovery of a sizable collection of fossil bird eggs. The material comes from the Upper Laetolil Beds, dated at ∼3.6-3.8 Ma, and the Lower Laetolil Beds, dated at 3.8 Ma to older than 4.3 Ma. The preservation of relatively complete eggs (other than those of ratites) is an extremely rare occurrence in the fossil record, and Laetoli is the only locality in Africa that has produced such well-preserved eggs. Deposition of carbonatite air-fall tuffs led to the rapid burial of the eggs sub-aerially, and they were then preserved in paleosols that were geochemically conducive to their preservation. The collection of fossil eggs from Laetoli can be assigned to at least five different species of ground-nesting birds, including two or three species of francolins, a species of guineafowl, and a larger bird of uncertain taxonomic status about the size of a bustard. Most of the eggs can be assigned to a large species of Francolinus, similar in size to the extant F. afer and F. leucoscepus. A smaller species of francolin, about the size of Francolinus coqui or F. sephaena, is also represented, but is less common. A single egg may represent an even smaller species of francolin, about the size of Francolinus lathami or F. nahani, but its attribution to Francolinus is less certain. The evidence of at least two species of Francolinus at Laetoli indicates that francolins were already taxonomically diverse in East Africa by the mid-Pliocene. Three eggs are similar in their overall dimensions and morphology to the living Numida meleagris, the helmeted guineafowl. An avian community including at least one small species of francolin, a larger francolin, and a guineafowl (as well as ostriches and a vulture) implies that the paleoecology at Laetoli was likely to have been open woodland, bushland, savanna or grassland. However, francolins and guineafowl generally require low brush and thickets for refuge, as well as trees to roost in at night, so they tend to prefer mosaic ecotonal habitats offering open feeding areas with good visibility, but with dense vegetation cover and patches of woodland nearby.
KW - Eggs
KW - Francolinus
KW - Numida
KW - Paleoecology
KW - Pliocene
KW - Taxonomy
UR - http://www.scopus.com/inward/record.url?scp=29044441843&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=29044441843&partnerID=8YFLogxK
U2 - 10.1016/j.jafrearsci.2005.07.002
DO - 10.1016/j.jafrearsci.2005.07.002
M3 - Article
AN - SCOPUS:29044441843
SN - 0899-5362
VL - 41
SP - 289
EP - 302
JO - Journal of African Earth Sciences
JF - Journal of African Earth Sciences
IS - 4
ER -