Significations et usages de Meganthropus

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Meganthropus Temporal range: Pleistocene
Pithecanthropus robustus, Sangiran Museum, Sragen, Indonesia
Conservation status
Fossil
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Primates
Family:	Hominidae
Genus:	Homo?
Species:	H. erectus?
Subspecies:	H. e. palaeojavanicus?
Trinomial name
†Homo erectus palaeojavanicus?

Meganthropus is a name commonly given to several large jaw and skull fragments from Sangiran, Central Java, Indonesia. The original scientific name was Meganthropus palaeojavanicus, and while it is commonly considered invalid today, the genus name has survived as something of an informal nickname for the fossils. As of 2005, the taxonomy and phylogeny for the specimens are still uncertain, although most paleoanthropologists consider them related to Homo erectus in some way. However, the names Homo palaeojavanicus and even Australopithecus palaeojavanicus are sometimes used as well, indicating the classification uncertainty. Of particular interest is that the finds were sometimes regarded as those of giants, although that is unsubstantiated.

After the discovery of a robust skull in Swartkrans in 1948 (SK48), the name Meganthropus africanus was briefly applied. However, that specimen is now formally known as Paranthropus robustus and the earlier name is a junior synonym.

Some of these finds were accompanied by evidence of tool use similar to that of Homo erectus. This is the reason it is often linked with that species.

  Fossil finds

The number of fossil finds has been relatively small, and it is a distinct possibility that they are a paraphyletic assemblage. Due to this, they will be discussed in detail separately.

  Meganthropus A/Sangiran 6

This large jaw fragment was first found in 1941 by von Koenigswald. Koenigswald was captured by the Japanese in World War II, but managed to send a cast of the jaw to Franz Weidenreich. Weidenreich described and named the specimen in 1945, and was struck by its size, as it was the largest hominid jaw then known. The jaw was roughly the same height as a gorilla's, but had a different form. Whereas in anthropoids the mandible (=jaw) has its greatest height at the symphysis, that is, where the two rami of the lower jaw meet, this is not the case in Sangiran 6, where the greatest height is seen at about the position of the first molar (M1). Weidenreich considered acromegalic gigantism, but ruled it out for not having typical features such as an exaggerated chin and small teeth compared to the jaw's size. Weidenreich never made a direct size estimate of the hominid it came from, but said it was 2/3 the size of Gigantopithecus, which was twice as large as a gorilla, which would make it somewhere around 8 feet (2.44 m) tall. The jawbone was apparently used in part of Grover Krantz's skull reconstruction, which was only 8.5 inches (21 centimeters) tall.

  Meganthropus B/Sangiran 8

This was another jaw fragment described by Marks in 1953. It was around the same size and shape as the original mandible, but it was also severely damaged. Recent work by a Japanese/Indonesian team repaired the fossil, which was an adult, and showed it to be smaller than known specimens of H. erectus. Curiously, the specimen did retain several traits unique to the first mandibular find and not known in H. erectus^[1]. No size estimates have been made yet.

  Meganthropus C/Sangiran 33/BK 7905

This mandibular fragment was discovered in 1979, and has some characteristics in common with previous mandible finds ^[2]. Its connection with Meganthropus appears to be the most tenuous out of the mandibular discoveries.

  Meganthropus D

This mandible and ramus was acquired by Sartono in 1993, and has been dated to between 1.4 and 0.9 million years ago. The ramus portion is badly damaged, but the mandible fragment appears relatively unharmed, although details of the teeth have been lost. It is slightly smaller than Meganthropus A and very similar in shape. Sartono, Tyler, and Krantz agreed that Meganthropus A and D were very likely to be representations of the same species, whatever it turns out to be ^[3].

  Meganthropus I/Sangiran 27

Tyler described this specimen as being a nearly complete but crushed cranium within the size limit of Meganthropus and outside the (assumed) limit of H. erectus. The specimen was unusual for having a double temporal ridges that almost meet at the top of the cranium and a heavily thickened nuchal ridge ^[4].

  Meganthropus II/Sangiran 31

This skull fragment was first described by Sartono in 1982. Tyler's analysis came to the conclusion that it was out of the normal range of H. erectus. The cranium was deeper, lower vaulted, and wider than any specimen previously recovered.It had the same double sagittal crest or double temporal ridge with a cranial capacity of around 800–1000cc. Since its presentation at the AAPA meeting in 1993, Tyler's reconstruction of Sangiran 31 has been accepted by most authorities. As with most fossils it was heavily damaged, but given the completeness of the post facial cranium the chances of error in its reconstruction are very small. Tyler's accepted reconstruction of Sangiran 31 shows a doubleor double temporal ridge. In either case, the temporal muscles extend to the top of the parietal where they almost join. There are no other Homo erectus specimens that exhibits this trait. Krantz's reconstruction of making Sangiran 31 a giant Homo habilis is dubious at best.

  Meganthropus III

This is another fossil with only tenuous ties to Meganthropus. It is what seems to be the posterior part of a hominid cranium, measuring about 10 to 7 cm. It has been described by Tyler (1996), who found that the occipital angle of the whole cranium must have been at about 120°, which, according to him, would be out of the known range of Homo erectus, the latter having a much more angled occiput. His interpretation of the cranial fragment was, however, questioned by other authorities including doubts that the fragment was really representing the part of a skull that Tyler had interpreted it as.

  Scientific interpretation

Weidenreich theorized that Meganthropus was a descendant of Gigantopithecus, and gave rise to Pithecanthropus, and then modern Asians. This hypothesis, part of the multi-regional theory of human evolution, has been discarded by mainstream paleoanthropology.

The second major theory, first proposed by J.T. Robinson, was that the Meganthropus finds are representative of a Southeast Asian australopithecine. This position has been adopted by several authorities, such as Koenigswald and Krantz, but they were still regarded as a vocal minority ^[5]. There was also discussion as to whether they are closer to Australopithecus or Paranthropus.

The majority of paleoanthropologists believe that Meganthropus is related to H. erectus, but it is not agreed upon how closely. Sartono believed that while it is related to H. erectus, the finds represent a new species, H. paleojavanicus. On the other side, several authors believe that they are merely the males of H. erectus, the alleged large size and robusticity being only due to early author's assumption that the females were males ^[6]. There appears to be a consensus that there are some differences between Meganthropus and conventional H. erectus, but opinion is variable as to what the differences mean.

  Extreme claims

Meganthropus has been the target of numerous extreme claims, none of which are supported by peer-reviewed authors. Perhaps the most common claim is that Meganthropus was a giant, one unsourced claim put them at 9 feet (2.75 m) tall and 750 to 1000 pounds (340 to 450 kilograms). No exact height has been published in a peer reviewed journal recently, and none give an indication of Meganthropus being substantially larger than H. erectus.

There have been some rumors of post-cranial material, but those have either yet to be published or belong to H. erectus. Reports, most if not all apparently from Australian researcher Rex Gilroy, place Meganthropus in Australia, and attach it to giant tools and even modern day reports. However, almost all paleoanthropologists maintain that Meganthropus is only known from central Java. In a similar way, some Bigfoot researchers claim that Bigfoot is a modern Meganthropus.

  References

• ^ ^ . Yousuke Kaifu, Fachroel Aziz, and Hisao Baba. Hominid Mandibular Remains From Sangiran: 1952-1986 collection. American Journal of Physical Anthropology. 2005. Abstract Available: here
• ^ G. Krantz, S. Sartono, and D. Tyler. A New Meganthropus Mandible from Java. Human Evolution, 1995. Abstract Available in the 1995 Supplements of the American Journal of Physical Anthropology.
• ^ ^ D. Tyler. Taxonomic Status of "Meganthropus" Cranial Material. Abstract Available in the 1993 Supplements of the American Journal of Physical Anthropology.
• ^ ^ ^ A.C. Durband 2003 A re-examination of purported Meganthropus cranial fragments. Paper not yet published. Abstract available in the American Journal of Physical Anthropology supplements for 2003. Also available: [7]
• ^ ^ A. Kramer. 1994. A Critical Analysis of Southeast Asian Australopithecines. Journal of Human Evolution volume 26, number 1.
• ^ Russell Ciochon, John Olsenm and Jamie James, Other Origins: The Search for the Giant Ape in Human Prehistory. Bantam Books, 1990.
• Bernard Heuvelmans. On the Track of Unknown Animals. Rupert Hart Davis, London, 1962.
• Franz Weidenreich. Apes, Giants, and Men. University of Chicago Press, 1996.

  External links

• Krantz's Skull Reconstruction
• Rex Gilroy's site on alleged Australian finds