TY - CHAP
T1 - Trends in postcanine occlusal morphology within the hominin clade
T2 - The case of Paranthropus
AU - Bailey, S. E.
AU - Wood, B. A.
N1 - Funding Information:
Thanks to W. Kimbel for providing access to casts of Au. afarensis, and P. Ungar and F. Grine for access to casts of A. africanus, Paranthropus and Homo specimens. SEB is grateful to W. Van Neer and W. Wendelen from Musée Royal d’Afrique Central and M. Harman from the Powell Cotton Museum for their assistance with the chimpanzee collections. The authors also thank the two anonymous reviewers for their helpful suggestions. Data collection and travel for SEB were funded by The George Washington University CASHP and the Max Planck Institute for Evolutionary Anthropology, Department of Human Evolution.
Publisher Copyright:
© 2007, Springer.
PY - 2007
Y1 - 2007
N2 - We have examined the crowns of chimpanzee, australopith, and Paranthropus species and early Homo in order to investigate two different, widely recognized, dental trends in Plio-Pleistocene hominin evolution. They are a reduction in crown size and morphological complexity in Homo, and an increase in crown size and morphological complexity in Paranthropus. A phenetic assessment of maxillary and mandibular molar crown non-metrical traits revealed that two australopith species (Au. africanus and Au. afarensis) are much more similar to each other than either is to Paranthropus, and together all hominins are distinctively different from chimpanzees (P. troglodytes and P. paniscus). The difference between Paranthropus and australopith postcanine teeth was 20–30 times greater than that between the australopith species and the difference between the two australopith species was about half the difference between the two extant chimpanzee species. The characters that contribute to the increase in crown complexity seen in Paranthropus do not appear to be primitive retentions from a great ape ancestor, and there is some evidence that the same, or a very similar, trend towards trait intensification is already present in australopiths. These traits include additional cusps on the maxillary and mandibular molars, and the expanded P 4 talonid. Early Homo exhibits the primitive condition for many of the molar traits, but it has also lost many other primitive traits (upper molar anterior and posterior foveae, for example) that are present in the australopiths. Relative to Pan, and similar to the australopiths, early Homo possesses a larger P4 with a somewhat expanded talonid, but this trend is subsequently reversed in later Homo. Our study reveals that some of the dental trends said to be characteristic of Homo actually appear relatively late in human evolution.
AB - We have examined the crowns of chimpanzee, australopith, and Paranthropus species and early Homo in order to investigate two different, widely recognized, dental trends in Plio-Pleistocene hominin evolution. They are a reduction in crown size and morphological complexity in Homo, and an increase in crown size and morphological complexity in Paranthropus. A phenetic assessment of maxillary and mandibular molar crown non-metrical traits revealed that two australopith species (Au. africanus and Au. afarensis) are much more similar to each other than either is to Paranthropus, and together all hominins are distinctively different from chimpanzees (P. troglodytes and P. paniscus). The difference between Paranthropus and australopith postcanine teeth was 20–30 times greater than that between the australopith species and the difference between the two australopith species was about half the difference between the two extant chimpanzee species. The characters that contribute to the increase in crown complexity seen in Paranthropus do not appear to be primitive retentions from a great ape ancestor, and there is some evidence that the same, or a very similar, trend towards trait intensification is already present in australopiths. These traits include additional cusps on the maxillary and mandibular molars, and the expanded P 4 talonid. Early Homo exhibits the primitive condition for many of the molar traits, but it has also lost many other primitive traits (upper molar anterior and posterior foveae, for example) that are present in the australopiths. Relative to Pan, and similar to the australopiths, early Homo possesses a larger P4 with a somewhat expanded talonid, but this trend is subsequently reversed in later Homo. Our study reveals that some of the dental trends said to be characteristic of Homo actually appear relatively late in human evolution.
KW - Australopithecus
KW - Dental morphology
KW - Early homo
KW - Plio-Pleistocene hominins
UR - http://www.scopus.com/inward/record.url?scp=78651442017&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=78651442017&partnerID=8YFLogxK
U2 - 10.1007/978-1-4020-5845-5_3
DO - 10.1007/978-1-4020-5845-5_3
M3 - Chapter
AN - SCOPUS:78651442017
T3 - Vertebrate Paleobiology and Paleoanthropology
SP - 33
EP - 52
BT - Vertebrate Paleobiology and Paleoanthropology
PB - Springer
ER -