The 1,000,000 year old child of Ngrejeng, Indonesia

Archaeology, Archeology, Palaeoanthropology, Palaeontology, Paleoanthropology, Paleontology
Fig. 10. Lateral (A), medial (B), occlusal (C), frontal (D), and posterior (E) views of Ng 8503. Scale: 30 mm.

NG 8503
Date Found: March 1985
Found By: Ngrejeng Villager
Locality: Near Ngrejeng Village, Indonesia
Announced: 1994
Fossil: Partial mandible (Right side), with M1 and M2. The latter had not yet erupted at time of death.
Age: 1.02 – 1.51 million years of age

Papers to check out:

1994 – Aziz et al – Preliminary report on recent
discoveries of fossil hominids from the Sangiran area, Java.

2005 – Kaifu et al – Hominid mandibular remains from Sangiran (1952-1986) Collection

2006 – Kaifu – Advanced dental reduction in Javanese Homo erectus

2011 – Wood – Encyclopedia of Human Evolution

Discovery of the Paranthropus of Peninj

Geology, Human Evolution, Human Origins, Palaeoanthropology, Paleoanthropology, Radiometric Dating

This evening on the 11th of January 1964, fossil hunter Kamoya Kimeu (1940-Present) was crossing what had been an Early Pleistocene delta to the western side of Lake Natron, Arusha, Tanzania. He was there with a team led by Richard Leakey in search of our earliest ancestors. Barely a few days into the expedition, Kimeu found a hominin mandible, not one of our ancestors, but just an intriguing. It is 1964 and by this time, OH 5, representative of Paranthropus boisei was already gracing the covers of magazines throughout the world. Thought to be the first human that used stone tools for the first time, the Nutcracker Man was not all he was cracked up to be. As more hominin fossils from the Late Pliocene and early Pleistocene began to show, it became more and more clear, that while P. boisei may have been found on an archaeological layer, this is not enough evidence to support a “he’s the first human” hypothesis.

Lengai_from_Natron

Ol Doinyo Lengai: A View from Lake Natron

Kimeu had found another representative of P. boisei at Peninj and it was a remarkably complete hominin mandible. The right condyle was missing and so too were the left and right coronoid processes, despite that the fossil had its complete set of teeth and that was particularly key. The teeth showed a great deal of wear  to the point that you could see the dentine beneath the enamel. This individual must have eaten alot of sedges and grasses throughout its life to give that sort of result. Grasses and sedges that you could find around deltas like that one that would have entered Lake Natron, when it wasn’t quite as salty. But when exactly did our hominin friend give up its spirit along the shores of the Lake. The stratigraphic layers in the region are like the pages of a picture book, no words, but pictures that can tell better narratives that Twilight could ever even dream of. The mandible was uncovered in a sedimentary layers, comprising the deltas alluvial deposits, sandwiched between two volcanic layers. The volcanic Tuff atop the layer that contained the fossil was previously dated to between 1.6 and 1.4 million years of age, while the basalt below was dated to 1.7 million years of age. You may think that the fossil is probably going to be between 1.7 and 1.4 million years of age, but the team of geologists at the site conducted further analysis at the site to help get a more accurate result. They settled on an age for the mandible of between 1.5 and 1.3 million years of age. Enough time for the ph of a lake to reach beyond 12.

Peninj

View of Lake Natron and a superimposed graphic of the hypothetical organisation of the layers around the fossil.

Since the discovery of the Peninj 1 mandible in 1964, another hominin with similar characteristics to P. boisei was found. Paranthropus aethiopicus now joined a trio of hominin species that became the Paranthropines, comprising boisei, robustus (South African hominin) and aethiopicus. Most of what we have collected of these creatures are crania and mandibles, though some postcranial remains have been found. Thankfully the teeth survive well and can tell us a great deal about their diet and the subtle, yet important questions of how they chew their greenery. There was a long drawn out debate over whether these three hominins deserved to live in a separate group – the Paranthropines. Originally, these hominins were classified as robust australopithecines and the palaeoanthropological community decided that a change was needed. The complete anatomy of the Peninj Hominin was never recovered and given that the mandible survived so well, this individual may have fallen to a carnivore in the delta. Below is a summary of the discovery that was made on the 11th of January 1964.

The Rise of the Terrible Beasts – Deinotheria

Continental Drift, Palaeoanthropology, Palaeozoology, Paleoanthropology, Volcanology, Zoology

Deinotherium. The Terrible Beast. A Proboscidean. The video below was one of my first introductions to the world of palaeoanthropology and 3D reconstructions of prehistoric life. It inspired me to learn more about the remote prehistory. This creature, a relative of the famed African Elephant, would have been between 4.5 to 5 metres in height at the shoulder, with a set of short downward-facing tusks and would have had a similar behavioural characteristics to modern day elephants. Nobody knows how long the trunk was, though the muscle attachments regions on the front of the skull can give some clues, its length remains conjectural. The set of downward-facing tusks have been the subject of much debate, ranging from sexual display to digging for roots and tubers to tree bark scraping. Again explanations vary. The Deinotheres has, thus far, been broken up into three species – D. giganteum, D. bozasi and D. indicum. The earliest examples of this group have been dated to about 23 million years ago (Early Miocene), while their extinction took place some time in the Middle Pleistocene, about 700,000 years ago. This was probably caused by the knock-on effects of climate change on the habitats in which they lived. The Deinotheres have a history that extends back into the Oligocene Epoch and this will be the subject of this discussion. As a side note, it is really sad that documentaries on human evolution and prehistoric beasts, do not explain the following. This is documentary material, in my opinion.

Deinotherium12
Deinotherium: A Reconstruction of the “Terrible Beast”

As Gondwana began to rupture apart 184 million years ago in the Early Jurassic. Africa was the first isolated baby continent of Gonwana. It remained as such, quite literally up until about 25 million years ago, 159 million years of isolaton for evolution to work its magic on a limited diversity of placental mammals that called Africa, home. But given that elephant-like creatures existed in Late Oligocene (34 – 28 Million Year ago) Pakistan, land bridges must have developed between Africa and Arabia / Eurasia as the continent made the relentless push north. With such unimaginable tectonic forces at work, it is inevitable that volcanism increases in activity. The tectonic dynamics were such in eastern Africa million of years ago that a unique type of volcanic eruption occurred. Everybody is familiar with the power of water, in the form of slow development floods and the devastating flash-flood. Lava is equally capable of flooding the landscape, not as we all know it today, but on a scale that we cannot comprehend. Everybody is familiar with the Cretaceous – Paleogene Extinction Event, but few are aware of the most devastating mass extinction event in the prehistory of the planet – The Permian – Triassic Extinction Event. It was brought on by a truly massive flood basalt eruption. This is what quite literally created Siberia, that’s right Siberia. Today, 252 million years on, the remains of that basalt eruption covers an area of over 2 million sq km² and may, back then, have covered over 7 million sq km². Eleven flood basalt eruption events have taken place within the last 250 million years. The Eritrean Intertrappean Beds is a much smaller events and featured episodes of volcanic activity followed by laying down of fluvial sediment, hence the “Inter-Trappean”. These beds can be up to 100 metres in depth and cover many square kilometres. This intermittent event has been dated from 29 to 23.6 million years of age.

800px-Blakey_35moll
Our Planet: The Oligocene Epoch (34 to 23 Million Year Ago)

Mendefera, is the town capital of the Debub Region of Eritrea and it sits atop the Eritrean Intertrappean Beds. It was at a number of outcrops of fluvial mudstones and siltstones that fossils of the early ancestors of Deinotherium were uncovered recently, called Prodeinotherium. Numerous other sites have revealed early Proboscideans such as Gomphotherium, which is likely to be the earliest representative of this intriguing family. During the Oligocene, Arabia and north-eastern Africa flirted with the Tethys Ocean promiscuously. So the sight you might have seen from the Eritean highlands, back then was swamp, river and lake populated landscapes, perfect for tropical wet forests, especially when the basaltic volcanism of the area was on hiatus. As Africa edged closer to Arabia and Eurasia, the lack of diverse fauna, may have allowed a large influx of Eurasian fauna to call Africa, home for the first time. There are an estimated six Trans-Tethyan Paleogene mammalian dispersals all of which were limited by the availability of land bridges. So large herbivores could not cross into or out of Africa without substantial land bridge crossing points. By the beginning of the Miocene, there was a massive faunal turnover in the form of African endemic species dying out and the movement of Eurasia fauna south into the continent. This dynamic change in faunal movements also included the northward movement of Prodeinotherium into Eurasia, evolving into the Deinotherium we all know and love.

Mendefera: Site of the ancestral Deinotherium Fossils
Mendefera: Site of the ancestral Deinotherium Fossils

Prehistoric beasts under attack