Molar crown formation in the Late Miocene Asian hominoids, Sivapithecus parvada and Sivapithecus indicus

Patrick Mahoney, Tanya M. Smith, Gary Schwartz, Christopher Dean, Jay Kelley

Research output: Contribution to journalArticle

21 Citations (Scopus)

Abstract

During the past decade, studies of enamel development have provided a broad temporal and geographic perspective on evolutionary developmental biology in Miocene hominoids. Here we report some of the first data for molar crown development in one hominoid genus, Sivapithecus. The data are compared to a range of extant and extinct hominoids. Crown formation times (CFTs), daily rates of enamel secretion (DSR), Retzius line number and periodicity, and relative enamel thickness (RET) were calculated in a mandibular first molar of Sivapithecus parvada and a maxillary first molar of Sivapithecus indicus from the Siwalik sequence of Pakistan. A CFT of 2.40 years for the protoconid of S. parvada and 2.25 years for the protocone of S. indicus lie within the range of first molar (M1) formation times for the majority of Miocene hominoids (1.96-2.40 years, excluding Proconsul heseloni), and are similar to an M1 from Gorilla (2.31 years) and M1s from Pan (2.22-2.39 years). This is unlike the longer CFTs in modern humans, which appear to be linked with their extended growth period. In contrast to extant great apes and humans, daily rates of enamel secretion are rapid in the Sivapithecus M1s during the early stages of growth, which seems to be a common pattern for most Miocene apes. The rapid accumulation of cuspal enamel in the Sivapithecus molars produced thicker enamel than either Pan or Gorilla in a comparable period of time. Future studies on larger samples of living and fossil hominoids are needed to clarify trends in crown development, which may be better understood in the context of life history strategies coupled with good data on body mass and brain size.

Original languageEnglish (US)
Pages (from-to)61-68
Number of pages8
JournalJournal of Human Evolution
Volume53
Issue number1
DOIs
StatePublished - Jul 2007

Fingerprint

enamel
Hominidae
tree crown
Miocene
Pan (Pongidae)
Gorilla
Pongidae
secretion
developmental biology
evolutionary biology
Pakistan
biology
brain
periodicity
body mass
time
life history
fossils
developmental stages
fossil

Keywords

  • Cross-striation
  • Enamel development
  • Enamel thickness
  • Primate evolution
  • Retzius lines

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics

Cite this

Molar crown formation in the Late Miocene Asian hominoids, Sivapithecus parvada and Sivapithecus indicus. / Mahoney, Patrick; Smith, Tanya M.; Schwartz, Gary; Dean, Christopher; Kelley, Jay.

In: Journal of Human Evolution, Vol. 53, No. 1, 07.2007, p. 61-68.

Research output: Contribution to journalArticle

Mahoney, Patrick ; Smith, Tanya M. ; Schwartz, Gary ; Dean, Christopher ; Kelley, Jay. / Molar crown formation in the Late Miocene Asian hominoids, Sivapithecus parvada and Sivapithecus indicus. In: Journal of Human Evolution. 2007 ; Vol. 53, No. 1. pp. 61-68.
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