The geological, isotopic, botanical, invertebrate, and lower vertebrate surroundings of Ardipithecus ramidus.
Sediments containing Ardipithecus ramidus were deposited 4.4 million years ago on an alluvial floodplain in Ethiopia's western Afar rift. The Lower Aramis Member hominid-bearing unit, now exposed across a > 9-kilometer structural arc, is sandwiched between two volcanic tuffs that have nearly identical 40Ar/39Ar ages. Geological data presented here, along with floral, invertebrate, and vertebrate paleontological and taphonomic evidence associated with the hominids, suggest that they occupied a wooded biotope over the western three-fourths of the paleotransect. Phytoliths and oxygen and carbon stable isotopes of pedogenic carbonates provide evidence of humid cool woodlands with a grassy substrate.
WoldeGabriel
Giday
G
Earth Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA. wgiday@lanl.gov
Ambrose
Stanley H
SH
Barboni
Doris
D
Bonnefille
Raymonde
R
Bremond
Laurent
L
Currie
Brian
B
DeGusta
David
D
Hart
William K
WK
Murray
Alison M
AM
Renne
Paul R
PR
Jolly-Saad
M C
MC
Stewart
Kathlyn M
KM
White
Tim D
TD
D000818:Animals; D002247:Carbon Isotopes / Q000032:analysis; D002254:Carbonates / Q000032:analysis; D017753:Ecosystem; D004777:Environment; D005002:Ethiopia; D035264:Flowers; D005580:Fossils; D019015:Geologic Sediments / Q000737:chemistry; D055593:Geological Phenomena; D015186:Hominidae; D007448:Invertebrates; D010103:Oxygen Isotopes / Q000032:analysis; D010944:Plants; D013696:Temperature; D014197:Trees; D014714:Vertebrates
D002247:Carbon Isotopes; D002254:Carbonates; D010103:Oxygen Isotopes