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Meganthropus palaeojavanicus
Meganthropus palaeojavanicus

Temporal range: Pleistocene 

Scientific classification
Kingdom:  Animalia
Phylum:  Chordata
Class:  Mammalia
Order:  Primates
Suborder:  Haplorhini
Infraorder:  Simiiformes
Family:  Hominidae
Genus: †Meganthropus
Species:  †Meganthropus palaeojavanicus

Meganthropus is a name commonly given to several large jaw and skull fragments found at the Sangiran site near Surakarta in 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 Meganthropus is often linked with that species as H. e. palaeojavanicus.
The results of a 2019 Study confirmed the presence of Meganthropus as a Pleistocene Indonesian hominid distinct from Pongo, Gigantopithecus and Homo, and further reveal that Dubois’s H. erectus paratype molars from 1891 are not hominin (human lineage), but instead are more likely to belong to Meganthropus.

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 Gustav 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 and approximately 400 to 600 lbs (181 – 272 kg) if scaled on the same proportions as a robust man or erect hominid. In his book Apes, Giants, and Man, Weidenreich states the following:
Quote:Therefore, it may not be too far from the truth if we suggest the Java giant [Meganthropus] was much bigger than any living gorilla and that the Chinese giant [Gigantopithecus] was correspondingly bigger than the Java giant – that is, one-and-a-half times as large as the Java giant, and twice as large as a male gorilla.
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. No size estimates have been made yet.

Meganthropus C/Sangiran 33/BK 7905
This jaw fragment was discovered in 1979, and has some characteristics in common with previous mandible finds. 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.

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 ridge (sagittal crest), which almost meets at the top of the cranium, and a heavily thickened nuchal ridge.

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 double temporal ridge. The temporal muscles extend to the top of the parietal where they almost join. There are no other Homo erectus specimens that exhibit this trait. Krantz's reconstruction of Sangiran 31 as a giant Homo habilis has been found to be 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, to include doubts that the fragment was actually the part of a skull that Tyler had thought it to be.

Studies of fossil teeth reveal another Pleistocene ape species from Southeast Asia

by Senckenberg Research Institute and Natural History Museum

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Lower jaw fragment of Meganthropus palaeojavanicus. Credit: Senckenberg

Together with an international team, Senckenberg scientists were able to document an additional fossil ape species in the Senckenberg hominid collection. The new species had already been described in 1950 as Meganthropus palaeojavanicus by Gustav Heinrich Ralph von Koenigswald, the founder of Senckenberg's paleoanthropological department, but at the time it was interpreted as a prehistoric human. Examinations of the anatomical dental structures now reveal that approximately one million years ago at least three additional species of hominids shared the habitat of Homo erectus on Java. The study is published today in the scientific journal Nature Ecology & Evolution.

More than 200 fossil teeth and jaw fragments have been discovered on the Indonesian island of Java to date. The majority of these hominid remains can be attributed to the extinct species Homo erectus, the first early human discovered outside of Europe. It is known that Homo erectus lived on Java during the time of the Pleistocene, approximately one million years ago, in the company of the ancestors of the modern-day Orangutans," explains PD Dr. Ottmar Kullmer of the Senckenberg Research Institute in Frankfurt, and he continues, "We were now able to show that yet another species of ape existed there at the same time."

Together with the study's lead author, Clément Zanolli of the University of Bordeaux, Kullmer and an international team studied fossil hominid teeth discovered in 1941 by Gustav Heinrich Ralph von Koenigswald, using top-of-the-line methods. "Our micro-computer tomographic studies and the analysis of the tooth enamel show that the teeth belong neither to Homo erectus nor to the Orangutans," explains Zanolli, and he adds, "In addition, there is no indication that they involve ancestors of modern humans."

[Image: 5cac7ea359636.jpg]
Comparison of a lower jaw fragment of Meganthropus with an Orangutan jaw and a reconstructed jaw of Homo erectus. Credit: Senckenberg

"In the past, there were repeated controversies involving the mysterious hominid Meganthropus, but there was no confirmed proof of its existence," says Kullmer. The new data now reveal that the teeth clearly differ from both the teeth of Homo erectus and those of Orangutans in regard to the distribution of the enamel thickness and the surface and position of the dentin cusps in the dental crowns' interior.

The wear pattern of Meganthropus' molars corresponds to that of fossil and modern-day Orangutans. Kullmer explains: "We therefore assume that the 'renamed' species primarily fed on fruit and other plant parts growing above-ground, similar to today's Orangutans. Homo erectus, on the other hand, probably had a more flexible diet, due to his ability to prepare food in various ways. However, there is no documentation to show whether a one-sided diet or even Homo erectus himself contributed to the extinction of Meganthropus."

According to the current study, it is now considered a fact that about one million years ago, in addition to Homo erectus at least three hominid genera inhabited the forests of today's Indonesian islands – a higher diversity than previously assumed. "And it is possible that we can add yet another genus, the giant ape known as Gigantopithecus. However, we are still lacking conclusive evidence in this regard," adds the paleoanthropologist.

Journal Reference:

Clément Zanolli et al. Evidence for increased hominid diversity in the Early to Middle Pleistocene of Indonesia, Nature Ecology & Evolution (2019). DOI: 10.1038/s41559-019-0860-z

Since the first discovery of Pithecanthropus (Homo) erectus by E. Dubois at Trinil in 1891, over 200 hominid dentognathic remains have been collected from the Early to Middle Pleistocene deposits of Java, Indonesia, forming the largest palaeoanthropological collection in South East Asia. Most of these fossils are currently attributed to H. erectus. However, because of the substantial morphological and metric variation in the Indonesian assemblage, some robust specimens, such as the partial mandibles Sangiran 5 and Sangiran 6a, were formerly variably allocated to other taxa (Meganthropus palaeojavanicus, Pithecanthropus dubius, Pongo sp.). To resolve the taxonomic uncertainty surrounding these and other contentious Indonesian hominid specimens, we used occlusal fingerprint analysis (OFA) to reconstruct their chewing kinematics; we also used various morphometric approaches based on microtomography to examine the internal dental structures. Our results confirm the presence of Meganthropus as a Pleistocene Indonesian hominid distinct from Pongo, Gigantopithecus and Homo, and further reveal that Dubois’s H. erectus paratype molars from 1891 are not hominin (human lineage), but instead are more likely to belong to Meganthropus.
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