Ramapithecus

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Ramapithecus
fossil jaw fragments from Ramapithecus

fossil jaw fragments from Ramapithecus

Temporal occurrence
Miocene
14 to 8 million years
Locations
Systematics
Monkey (anthropoidea)
Old World Monkey (Catarrhini)
Human (Hominoidea)
Apes (Hominidae)
Ponginae
Ramapithecus
Scientific name
Ramapithecus
Lewis , 1934

Ramapithecus is an extinct species of primates from the family of the apes (hominids). Parts of a maxillary bone and some teeth were found in 1932 by George Edward Lewis near Haritalyangar, in the Indian area of ​​the Siwaliks , and described scientifically for the first time in 1934.

The type species of the genus is Ramapithecus brevirostris . To Ramapithecus identified fossils are very similar to those of Sivapithecus .

Naming

Ramapithecus is an artificial word . The name of the genus refers on the one hand to Rama , a figure of Indian mythology and on the other hand is derived from the Greek word πίθηκος ( ancient Greek pronounced píthēkos : "monkey"). The epithet of the type species, Ramapithecus brevirostris , refers to the reconstruction of the shape of the preserved facial skull, derived from Latin brevis = "short" and rostrum "snout". Ramapithecus brevirostris consequently means "short-snouted Rama monkey".

Initial description

The holotype of the genus and the type species Ramapithecus brevirostris is a partially dentate, right upper jaw fragment (archive number YPM 13799).

Features and dating

The Ramapithecus attributed fossils were dated to between 14 and 8 million years ago and have some similarities to the human dentition: So the chewing surfaces of the are molars and premolars flattened and less pointed than that of many apes , the canines are small and dull, the The jaw is shortened, resulting in a relatively short, flat snout , and the dental arches are indicated to be parabolic (and not, as is the case with recent chimpanzees , U-shaped).

Due to the only fragmentary survival of fossils, Ramapithecus and Sivapithecus have at most rough estimates of their brain volume, according to which it corresponds to Dryopithecus and similarly sized chimpanzees, i.e. it was probably significantly less than 400 cm³.

Position in the family tree of the great apes

Due to the features of the dentition and in particular due to the reconstruction of a relatively short, flat snout by Elwyn L. Simons , Ramapithecus was interpreted in a study that was highly regarded at the time as the direct ancestor of the hominini - leading to the genus Homo - and as a " missing link ".

Historical background

In 1944 Theodosius Dobzhansky published the essay On species and races of living and fossil man , in which he hypothesized that there was only one, albeit varied, species of hominini at any one time . In 1950, Ernst Mayr took up Dobzhansky's assumptions at the Cold Spring Harbor Symposium on Quantitative Biology and sharpened them in his lecture on “Taxonomic categories in fossil hominids” to the effect that the large number of species names that had been given up to now had to be reduced. Mayr convinced the paleoanthropologists to assign all alleged human ancestors discovered in the meantime to the genus Homo . As a result, for example , the fossils then known as Pithecanthropus erectus were renamed Homo erectus ("the erect man") and the upright gait was identified as an essential feature of the genus Homo . Furthermore, the paleoanthropologists at that time acquired the view that there was only one species of the genus Homo - originating from the Australopithecines - which, according to the mechanisms of the synthetic theory of evolution also formulated by Ernst Mayr , slowly and gradually increases Homo sapiens developed.

This line of argument also influenced Elwyn Simons and his former student David Pilbeam , who projected the synthetic evolution theory's hypothesis of a slow and gradual change in shape into the past. Although only one fossil - the type specimen YPM 13799 - was available in the mid-1960s, they interpreted the short and flat snout of Ramapithecus brevirostris 1965 , which they reconstructed in 1965, to mean that this was a feature of upright gait, as a rounded skull was easier on one Carrying a vertically standing spine is like a skull with a protruding snout. The upright gait also enabled the hands to use tools, which is why all fossils with such characteristics could be placed in the immediate ancestry of man. At the same time, they adopted a hypothesis by Charles Darwin , who in 1871 interpreted the reduction in size of the canines as a result of the use of stone tools , which in turn presupposes a bipedal way of life. “In this way, a creature that was initially regarded as the earliest hominid species was interpreted as a cultural creature - that is, as a primitive version of today's humans and not as a cultured ape.” As the sediments from which the fossil YPM 13799 was recovered was, undoubtedly of old age, Simons and Pilbeam concluded “that the first humans appeared at least fifteen, perhaps even thirty million years ago, and this view was shared by the vast majority of anthropologists. In addition, the belief in such an ancient origin of mankind ensured a calming distance between man and the rest of nature, which many received with satisfaction. "

As early as 1967, a time scale for the evolution of primates, calculated using molecular biological models, aroused initial doubts about this age assignment, since according to these calculations the line leading to humans did not change from that to chimpanzees until 5 million years ago (later corrected to 7 million years) leading line separated. After Pilbeam discovered another intact, but almost V-shaped jaw from Ramapithecus in 1976 , it also became apparent that the jaw fragments of the first fossil had been inaccurately - incorrectly rounded off - reconstructed, and in 1982 Pilbeam Ramapithecus finally became part of the ancestral line of the Hominini locked out.

Today's name variants

The status of Ramapithecus as an independent genus is controversial today. The genus may be identical to Sivapithecus : Some researchers interpret Ramapithecus as the female form of Sivapithecus . Should Sivapithecus represent male and Ramapithecus female individuals of the same species, the generic name Sivapithecus would have priority, since it was named by Guy Ellcock Pilgrim in 1910 .

Since after the naming of Ramapithecus brevirostris it was recognized that an upper jaw fragment named Dryopithecus punjabicus by Guy Ellcock Pilgrim as early as 1915 belongs more to the genus Ramapithecus than to the genus Dryopithecus and is almost identical to the fossils named Ramapithecus brevirostris , the species Ramapithecus accordingly became the species Ramapithecus Rules of taxonomy renamed Ramapithecus punjabicus . Those researchers who interpret Ramapithecus and Sivapithecus as male and female variants of the same species, the fossils are therefore now also referred to as Sivapithecus punjabicus in their specialist publications .

Also controversial position of this genus is (s) in the family tree of primates : Some researchers consider them to be the ancestor of extant great apes (hominids), other than its Schwestertaxon . Still others - such as Richard Leakey - place them near the orangutans ; accordingly, it would only be settled after the great apes were divided into an Asian (orangutan) and an African line ( gorillas , chimpanzees and humans ). Additional findings will probably only bring clarity about Ramapithecus .

See also

literature

Individual evidence

  1. ^ A b G. Edward Lewis: Preliminary notice of new man-like apes from India. In: American Journal of Science. Series 5, Volume 27, 1934, pp. 161-181, doi: 10.2475 / ajs.s5-27.159.161
  2. ↑ Elwyn L. Simons: On the mandible of Ramapithecus. In: PNAS . Volume 51, No. 3, 1964, pp. 528-535, doi: 10.1073 / pnas.51.3.528 , full text with numerous illustrations
  3. ↑ a b Fiorenzo Facchini : The origins of mankind. Konrad Theiss Verlag, 2006, p. 63
  4. ^ David Begun : Planet of Live. Apes. In: Scientific american. August 2003, p. 80
  5. ↑ Elwyn L. Simons : The phyletic position of Ramapithecus. In: Postilla. Volume 57, 1961, pp. 1-9. Also chapter 27 in: Russell L. Ciochon and John G. Fleagle (Eds.): Primate Evolution and Human Origins. Routledge, New York 1987, ISBN 978-0-20201175-2
  6. ^ Theodosius Dobzhansky: On species and races of living and fossil man. In: American Journal of Physical Anthropology. Volume 2, No. 3, 1944, pp. 251-265, doi: 10.1002 / ajinpa.1330020303
  7. ^ Ernst Mayr : Taxonomic categories in fossil hominids. In: Cold Spring Harbor Symposia on Quantitative Biology 1950 Volume 15, 1950, pp 109-118, doi: 10.1101 / SQB.1950.015.01.013 , excerpt
  8. ^ Ian Tattersall : The Strange Case of the Rickety Cossack - and Other Cautionary Tales from Human Evolution. Palgrave Macmillan, New York 2015, p. 72, ISBN 978-1-137-27889-0
  9. ↑ David R. Pilbeam and Elwyn L. Simons: Some problems of hominid classification. In: American Scientist. Volume 53, No. 2, 1965, pp. 237-259, jstor.org
  10. ^ Elwyn L. Simons, David Pilbeam: Preliminary Revision of the Dryopithecinae (Pongidae, Anthropoidea). In: Folia Primatologica. Volume 3, 1965, pp. 81-152, doi: 10.1159 / 000155026
  11. ^ Charles Darwin: The descent of man, and selection in relation to sex. Volume 1, 1871, published by John Murray, p. 144. Full text - Darwin had also emphasized the connection between bipedalism and tool use. (P. 142)
  12. ↑ Richard Leakey : The First Traces. About the origin of man. Goldmann, Munich 1999, p. 25, ISBN 3-442-15031-0 .
  13. ↑ Vincent M. Sarich, Allan C. Wilson: Immunological time scale for hominid evolution. In: Science . Volume 158, 1967, pp. 1200-1203, doi: 10.1126 / science.158.3805.1200
  14. ↑ Aylwyn Scally and Richard Durbin: Revising the human mutation rate: implications for understanding human evolution. In: Nature Reviews Genetics. Volume 13, 2012, pp. 745-753, doi: 10.1038 / nrg3295
  15. ↑ David Pilbeam et al .: New hominoid primates from the Siwaliks of Pakistan and their bearing on hominoid evolution. In: Nature . Volume 270, 1977, pp. 689-695, doi: 10.1038 / 270689a0
  16. ↑ Susan Lipson and David Pilbeam: Ramapithecus and hominid evolution. In: Journal of Human Evolution. Volume 11, No. 6, 1982, pp. 545-546, IN3, 547-548, doi: 10.1016 / S0047-2484 (82) 80108-5
  17. ↑ Peter Andrews and Ibrahim Tekkaya: A revision of the Turkish Miocene hominoid Sivapithecus meteai. In: Palaeontology. Volume 23, No. 1, 1980, pp. 85–95, full text (PDF)
  18. ↑ Guy Ellcock Pilgrim : Notices of new Mammalian genera and species from the Tertieries of India-Calcutta. In: Records of the Geological Survey of India. Volume 40, 1910, pp. 63-71.
  19. ↑ calphotos.berkeley.edu : various images of Sivapithecus punjabicus = Ramapithecus punjabicus = Ramapithecus brevirostris
  20. ↑ Richard Leakey, The First Tracks. On the origin of man, p. 28