Middle Pleistocene Homo naledi

John Hawks discusses the latest news on the Rising Star Project:

Africa’s richest fossil hominin site has revealed more of its treasure. It’s been a year and a half since scientists announced that a new hominin species, which they called Homo naledi, had been discovered in the Rising Star Cave outside Johannesburg.

Now they say they have established and published the age of the original naledi fossils that garnered global headlines in 2015. Homo naledi lived sometime between 335 and 236 thousand years ago, making it relatively young.

They’ve also announced the discovery of a second chamber in the Rising Star cave system, which contained additional Homo naledi specimens. These include a child and the partial skeleton of an adult male with a well-preserved skull. They have named the skeleton “Neo” – a Sesotho word meaning “a gift”.

The Conversation Africa’s Science Editor Natasha Joseph asked Professor John Hawks, a member of the team, to explain the story behind these finds.

To an ordinary person, 236 000 years is a very long time ago. Why does the team suggest that in fact, Homo naledi is a “young” species?

The course of human evolution has taken the last seven million years since our ancestors diverged from those of chimpanzees and bonobos. The first two-thirds of that long history, called australopiths, were apelike creatures who developed the trick of walking upright on two legs.

Around two million years ago some varieties of hominins took the first real steps in a human direction. They’re the earliest clear members of our genus, Homo, and belong to species like Homo habilis, Homo erectus and Homo rudolfensis.

Homo naledi looks in many ways like these first members of Homo. It’s even more primitive than these species in many ways, and has a smaller brain than any of them. People outside our team who have studied the fossils mostly thought they should be around the same age. A few had the radical idea that H. naledi might have lived more recently, maybe around 900,000 years ago.

Nobody thought that these fossils could actually have come from the same recent time interval when modern humans were evolving, a mere 236 to 335 thousand years ago.

How do you figure out a fossil’s age?

We applied six different methods. The most valuable of these were electron spin resonance (ESR) dating, and uranium-thorium (U-Th) dating. ESR relies on the fact that teeth contain tiny crystals, and the electron energy in these crystals is affected by natural radiation in the ground over long periods of time after fossils are buried.

U-Th relies on the fact that water drips into caves and forms layers of calcite, which contain traces of uranium. The radioactive fraction of uranium decays into thorium slowly over time. So the proportion of thorium compared to uranium gives an estimate of the time since the calcite layers formed. One of these calcite deposits, called a flowstone, formed above the H. naledi fossils in the Dinaledi Chamber. That flowstone helps to establish the minimum age: the fossils must be older than the flowstone above them.

For these two methods, our team engaged two separate labs and asked them to process and analyse samples without talking to each other. Their processes produced the same results. This gives us great confidence that the results are reliable.

What does the discovery of Homo naledi’s age mean for our understanding of human history and evolution?

For at least the past 100 years, anthropologists have assumed that most of the evolution of Homo was a story of progress: brains got bigger over time, technology became more sophisticated and teeth got smaller as people relied more upon cleverness to get better food and prepare it by cooking.

We thought that once culture really got started, our evolution was driven by a feedback loop – better food allowed bigger brains, more clever adaptations, more sophisticated communication. That enabled better technology, which yielded more food, and so on like a snowball rolling downhill.

No other hominin species could compete with this human juggernaut. You would never see more than one form of human in a single part of the world, because the competition would be too intense. Other forms, like Neanderthals, existed within regions of the world apart from the mainstream leading to modern humans in Africa. But even they were basically human with large brains.

That thinking was wrong.

Africa south of the equator is the core of human evolutionary history. That’s where today’s human populations were most genetically diverse, and that diversity is just a small part of what once existed there. Different lineages of archaic humans once lived in this region. Anthropologists have found a few fossil remnants of these archaic populations. They’ve tried to connect those remnants in a straight line. But the genetic evidence suggests that they were much more complex, with deep divisions that occasionally intertwined.

H. naledi shows a lineage that existed for probably more than a million years, maybe two million years, from the time it branched from our family tree up to the last 300,000 years. During all this time, it lived in Africa with archaic lineages of humans, with the ancestors of modern humans, maybe with early modern humans themselves. It’s strikingly different from any of these other human forms, so primitive in many aspects. It represents a lost hominin community within which our species evolved.

I think we have to reexamine much of what we thought we knew about our shared evolutionary past in Africa. We know a lot of information from a few very tiny geographic areas. But the largest parts of the continent are unknown – they have no fossil record at all.

Explorers Mathabela Tsikoane, Maropeng Ramalepa, Dirk van Rooyen, Steven Tucker (seated), and Rick Hunter (seated) inside the Rising Star cave system. Wits University/Marina Elliott

We’re working to change that, and as our team and others make new discoveries, I’m pretty sure we are going to find more lineages that have been hidden to us. H. naledi will not be the last.

The first Homo naledi discoveries were made in the Dinaledi Chamber. What led researchers to the second chamber? And what did you find there?

The Dinaledi Chamber is one of the most significant fossil finds in history. After excavating only a very tiny part of this chamber, the sample of hominin specimens is already larger than any other single assemblage in Africa.

The explorers who first found these bones, Rick Hunter and Steven Tucker, saw what the team was doing when they were excavating in the chamber. The pair realised that they might have seen a similar occurrence in another part of the cave system. The Rising Star system has more than two kilometres of mapped passages underground. In another deep chamber, accessed again through very tight underground squeezes, there were hominin bones exposed on the surface.

Our team first began systematic survey of this chamber, which we named the Lesedi Chamber, in 2014. For two years Marina Elliott led excavations, joined at times by most of the team’s other experienced underground excavators. They were working in a situation where bones are jammed into a tight blind tunnel. Only one excavator can fit at a time, belly-down, feet sticking out. It is an incredibly challenging excavation circumstance.

Geologist Dr Hannah Hilbert-Wolf studying difficult to reach flowstones in a small side passage in the Dinaledi Chamber. Wits University

The most significant discovery is a partial skeleton of H. naledi, with parts of the arms, legs, a lot of the spine and many other pieces, as well as a beautifully complete skull and jaw. We named this skeleton “Neo”. We also recovered fragments of at least one other adult individual, and one child, although we suspect these bones may come from one or two more individuals.

Is there a way for people to view these discoveries in person?

On May 25 – Africa DayMaropeng at the Cradle of Humankind World Heritage Site outside Johannesburg will open a new exhibit with the discoveries from the Lesedi Chamber and the Dinaledi Chamber together for the first time.

For people outside South Africa, the data from our three-dimensional scans of the new Lesedi fossils are available online.

Anyone can download the 3D models, and people with access to a 3D printer can print their own physical copies of the new fossils, as well as the fossils from the Dinaledi Chamber. It’s a great way for people to see the evidence for themselves.

Reprint from The Conversation

The Famous Anaktuvuk Pass, Alaska

The famous Anaktuvuk Pass, Alaska:

Dr. Lewis Binford (1931 – 2011) spent 1969 living with a Nunamuit group to understand their way of life. He was particularly interested in the material culture of this group. If you can understand the biography of Nunamuit objects, maybe this could shed some light on the Mousterian Technocomplex. It was hoped that this would help him understand life for Homo neanderthalensis during the Ice Age in Europe.

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

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

Returning Kabwe Man To Zambia: Renewed Efforts for 2015

Everybody has heard of the Elgin Marbles and the debate surrounding the right’s of countries to those artefacts. These marbles are famous the world over but this story is repeated many more times not just in archaeology, but palaeoanthropology also.  Zambia was once a colony of the British Empire and it was during that time that a certain hominin skull E 686 was uncovered. This skull Mr-Kabimba-with-Hon.-Susan-Kawandami-in-Kaoma-for-the-Kazanga-ceremony-is now lies in the vaults of the South Kensington Museum, London. In Zambia, Deputy Minister Susan Kawandami (pictured) recently reported before the Zambian Parliament that years of talks failed to secure the return of E 686 to Zambia with the Natural History Museum, London prepared to make copies of the skull instead. Kawandami will now establish new discussions through UNESCO, while Minister of Chiefs and Traditional Affairs, Nkandu Luo will visit London to establish a dialogue with the Trustees of the Museum.

E 686

If the Natural History Museum is ever to return the fossil, one thing is for sure, Zambia will have to convince the London Museum, that it is proactive in heritage (particularly palaeoanthropological) promotion and will ensure great care for the priceless skull. Which is currently not the case. The famed locality has no interpretative centre, no sign, no indication that two pivotal hominin bones – E 686 (Skull) and E 691 (tibia), were uncovered there. On the 17th of June 1921, A. S. Armstrong and A. W. Whittington uncovered those remains at Mutwe wa Nsofu, Mulungushi Road, Kabwe, Zambia. That same year, the fossils were given a new human species name – Homo rhodesiensis. This species has, thus far, only ever been found in Africa and it is a species that is seldom used by palaeoanthropologists. Most consider it a variation of Homo heidelbergensis. A key species that diverged into Homo sapiens (in Africa) and Homo neanderthalensis (in Europe). From about 1.5 million to 500,000 years ago, is a time that palaeoanthropologists have difficulty understanding due to the particularly patchy fossil record. So, what I have described is quite simplistic and many would argue over the exact details. The two fossils represent two adults males, that lived around 1 million years ago. Sadly, given they were found in the 1920’s, excavations in the field of human evolution were in their infancy and so, grossly inaccurate. The only way to date the site was through biostratigraphy. By looking at the animals that were found in the layers in which the fossils were found, later palaeoanthropologists compared those assemblages to strata at other sites which were radiometrically dated. The Kabwe stratigraphy was quite similar to Bed IV at the Oldupai Gorge which was dated to between 780,000 years to 1.3 million years.

homo_heidel_655_fs
E 686 (Kabwe 1) fleshed out in this hyper-realistic reconstruction by John Gurche (http://www.gurche.com)

Zambia’s National Heritage and Conservation Commission (NHCC) is now in the process of rehabilitating the site. Chief executive officer of the commission, Collins Chipote warned that though the site was intact, it needs to be secured and developed. A Kabwe Mining museum was commissioned by Nkandu-LuoMinster Nkandu Luo (pictured), which will be run by the Lead-Zinc Mining company Enviro-Processing Ltd. a subsidary of the giant Berkeley Mineral Resources PLC. More effort is required on the part of Zambia to show that they have the determination to celebrate their priceless heritage and right now, there seems to be no action, but plenty of talking.

The ‘Black Hole’ of Palaeoanthropology – A Message For Isis

The ‘Black Hole’ of Palaeoanthropology is not a term you hear very often, but then again what is there to say about the biogeographic history of a 1.77 million square kilometer region (Turkey, Saudi Arabia, and Iran) with virtually no faunal, human or archaeological sites. At this point it would seem easy to resign yourself to the words of Timothy D. White at the dawn of the 21st century, that we are not going to find many more fossil hominins. The mark of a great palaeoanthropologist is to never give up that curiosity for the unknown. Since White’s depressing prediction, he has been roundhouse kicked to Wrongville, with the spectacular finds of Ethiopia, South Africa, Myanmar, China, Flores and much much more. We have learned so much thus far, don’t lets forget this. Sounds great but these inevitably throw up more questions than answers. And the ‘Black hole’ is a particularly hard nut to crack. middle_east_graphic_2003

What does archaeology have to offer? Ethiopia features the earliest concrete evidence for hominin stone tool manufacture. At 2.6 million years of age it predates the earliest known human – Homo habilis – by less than 300,000 years years (Fossil Code: A.L. 666). Saudi Arabia has a rather rich representation of Mode 1 (Oldowan) stone tool clusters. If you don’t know to millimeter accuracy where the stone tool was found, or if it is a surface find then it is worthless to science.  The Saudi sites were also used during the Holocene (11,700 years ago to present), begging the question how can you separate Early Pleistocene (2.5 million years ago to 700,000 years ago) from Holocene activity? At least we can tell that hominins took one route out of Africa. Stone tools similar to the Oldowan found at Perim Island supports the hypothesis that early hominins crossed the Bab al Mandab Strait (20 miles wide). Iran has probably the most depressing lack of archaeological evidence of the region. Isolated finds dominate, both the Oldowan and Acheulean records of Iran and few excavations have taken place. South of the Caspian Sea is the site of Ganj Par, which yielded 100 limestone tools within half a hectare. This assemblage shares similarities with those of Ubediya, Israel and the Oldupai Gorge (also known as the Olduvai Gorge), Tanzania. Turkey repeats much the same story. Of the 200 Palaeolithic sites, less than 25 have been even partially excavated. The majority are restricted to the fringes of the Anatolian plateau.  None are any older than 1.3 million years of age, further supported by Argon-Argon dating of Kula, western Turkey to 1.24 million years of age. The site was the location of a palaeomeander which contained a solitary Quartz flake, 5 x 4 cm. Volcanic activity interfered with the palaeomeander and it was that lava flow that allowed the date to be so accurate. The take-home-message from Turkey is the earliest securely dated archaeological remains support the 1.1 million years calculated for the Kocabas skullcap, which shares affinities with OH 9 and KNM ER 3733, attributed to H. erectus. Debate continues as to its taxonomic status, but it does reflect a great deal of H. erectus characteristics. The Archaeology tells us that hominins with the ability to make stone tools were already out of Africa 1.8 million years ago, at the site of Dmanisi, Georgia.Untitled-2

It is the richest fossil hominin location at the ‘black hole’ fringe. The Fall of 2013 was just another milestone in sites long history of archaeological investigation. The discovered cranium (D4500) was reunited with its jaw (D2600) and the team of palaeoanthropologists led by David Lordkipandize  concluded that the five individuals represented members of the same species, but retracted the classification of D2600 (Homo georgicus) for Homo erectus ergaster georgicus. This raised some eyebrows in the palaeoanthropological community, particularly Fred Spoor, palaeoanthropologist and lecturer at the UCL Department of Anthropology,  who pointed out that such an action is not outlined in the code of zoological nomenclature. This is a minor debate in the palaeoanthropology, but most agree that Homo erectus exhibited a variation comparable to that seen in modern Homo sapiens today. Dmanisi is proof that hominins were already out of the African continent by 1.8 million years. Additionally, although the dating of the hominins of Java are in the doldrums, these specimens could be as much as 1.8 million years of age. Prior to that time some hominin species made it’s way north, but which one?

Dmanisi, Georgia on the fringe of the palaeoanthropological 'Black Hole'
Dmanisi, Georgia on the fringe of the palaeoanthropological ‘Black Hole’

On the 23rd of January 1995, a French-Chadian team of palaeontologists discovered a fragment of fossil jaw (Fossil Code: KT 12/H1) lying on the gravel desert of northern Chad. The fossil (nicknamed “Abel”) could not be accurately dated, nevertheless stratigraphic layers nearby suggested it could as much as 3.5 million years of age. Back then, the river Bahr El Ghazal flowed into a 3 million square kilometer lake called Megachad.  This hominin foraged on grasses that dominated the Koro Toro region. The palaeontologists gave “Abel” a new species name – Australopithecus bahrelghazali distinguishing it from another australopithecean – Australopithecus afarensis. That species lived in the eastern region of the continent, over 2,500 km from the Bahr El Ghazal site. The animal remains found in the stratigraphic layers of both regions were pretty much identical, which means the ecosystems were the same. Therefore, you can see why some palaeoanthropologists consider it plausible that “Abel” is just another Au. afarensis. This goes back to the argument that, what we are looking at here is just another variation of the same species. Either way, here we have australopitheceans in eastern and north central Africa. Theoretically, it is plausible for australopitheceans to have made their way into Arabia.

Chadian Basin: The blue outlines the rough shape and size of Megachad. Note that KT 12/ H1 was uncovered at the site indicated as "KT".
Chadian Basin: The blue outlines the rough shape and size of Megachad. Note that KT 12/ H1 was uncovered at the site indicated as “KT”. (Lebatard et al – 2010 – Application of the authigenic 10Be/9Be dating method to continental sediments: Reconstruction of the Mio-Pleistocene sedimentary sequence in the early hominid fossiliferous areas of the northern Chad Basin)

Every organism has a landscape format that they thrive within. Lions are quite at home in the savannah, Tigers frolick in the dense jungles of the Indian subcontinent and hominins, particularly australopitheceans, were quite at home in savannahs. If we are to prove that they made their way into Arabia, there should be an extension of savannah into the Eurasia 3-4 million years ago. Sadly we are not seeing this, but what do we see. The faunal record of Saudi Arabia is particularly fragmented and sparse. Western Turkey (Calta) 2.3 million years ago, saw Raccoons, Giraffes, Hippos and the extinct “Running” Hyena. Many associate Bethlehem with the Christian story, but few know that at about the same time, this region featured Raccoons, Sabre-Toothed Cats, Rhino, an ancestor to the Mammoth and ancestor to the modern boar. While 110 kilometers north of Bethlehem and 700,000 years later, Baboons lived south of the Lake of Tiberias, around Ubeidiya. Lakes were magnets for faunal activity and therefore hominin activity.

An Nedfud Desert Fringe
An Nedfud Desert Fringe (http://saudi-archaeology.com/background/geography-arabian-peninsula/attachment/nafud-back-of-jabal-qatar/)

The An Nedfud desert of northern Saudi Arabia is classic wilderness today, 2 million years ago it was the hub of a diverse ecosystem with a lake as the centrepiece. The faunal remains were recovered from three localities and share similarities with the kind of fauna you would expect at Ubeidiya and the Oldupai Gorge. Hippos were found at these sites and since modern day counterparts prefer standing water to a depth of 5 meters, it gives an initial sense of the size of ‘Lake An Nedfud’. A lake capable of supporting fish life, but this is not the only lake to have supported faunal biodiversity in the ‘Black Hole’. ‘Lake Negev’ developed around 1.8 and disappeared around 1.5 million years ago under ever increasingly arid conditions. It supported fish populations and laid down 15 m thick sediments over 18 sq km². Besides these lakes, there were smaller lakes, Oases and springs that would have allowed hominins to hop, skip and jump out of Isis territory and into the more accommodating environments of Europe and eastern Asia. Looking at the faunal remains you can get a sense of the climate that prevailed at whatever time period you are interested in. The climatic mapping of the Pliocene and Early Pleistocene of the ‘Black Hole’ are, you’ve guessed it understudied. We do know that two and a half million years ago, the forests of Azerbaijan gave way to Savannah and the Arabian peninsula experienced 2 million years of humid conditions, capable of keeping many large (now extinct) rivers topped up.

Distribution of Landscapes (Dowsett et al. 1994, Figure 11)
Distribution of Landscapes (Dowsett et al – 1994 – Joint investigations of the Middle Pliocene climate I: PRISM paleoenvironmental reconstructions)

There you have it. We know alot, but we know so very little about this massive region of the world. We lack fossil hominins in this region and I don’t think Isis would be willing in finding their early ape ancestry any time soon. It would definitely be a useful distraction from Wahhabism. Do something useful for a change, Isis! Get out there and find us those damn fossils! You ignorant misogynistic apes!

Meganthropus palaeojavanicus – The Early Years of Palaeoanthropological Research (1942 – 1955)

Meganthropus palaeojavanicus (from the Ancient Greek, meaning Ancient Java’s Great Human) is a redundant genus and species that was first formally introduced by Gustav vonKoenigswald (1902 – 1982) in 1950. The genus once referred to a set of fossils found on the island of Java in the 1930’s, 1940’s, 1950’s and 1980’s. The Javan fossils are now attributed to the hominin Homo erectus that lived from 1.9 million years ago to 300,000 years ago and had a range from Africa to Eurasia.

vonKoenigswald’s Meganthropus palaeojavanicus

von_Koenigswald
Gustav Heinrich Ralph vonKoenigswald (1902 – 1982)

On the 15th of January 1942, the Director of the Geological Survey of the Netherlands Indies, W. C. B. Koolhoven wrote a letter to anatomist and palaeoanthropologist, Franz Weidenreich informing him that vonKoenigswald wishes the 1939 and 1941 to be attributed to a new genus and species of ape called M. palaeojavanicus. In 1945, Weidenreich referred to it as “vonKoenigswald’s Meganthropus palaeojavanicus”. Held in the Senckenberg Forschungsinstitute und Naturmuseum, an unpublished 1949 scientific paper written by vonKoenigswald proposes that Sangiran 1a,  It was not until 1950, the vonKoenigswald committed his new genus and species to print in a formal introduction. As the sixth decade of the 20th century developed, consensus shifted towards H. erectus as the taxonomic appellation of the Javan fossils.

“Meganthropus” Fossils

The following are a list of fossils that were taxonomically assigned to Meganthropus, but have now been officially assigned to H. erectus

Franz Weidenreich
Franz Weidenreich (1873 – 1948)

Sangiran 6a

Kromopawiro (a team member) discovered the fossil adult mandible fragment “near Glagahombo, north of Sangiran” not far from where another cranium was uncovered in 1939 and south of Sangiran 4’s location. Weidenreich described the 1.6 million year old fossil in 1945, in which he pointed out the size of the mandible and the primitive premolar morphology as evidence to support the application of a new genus and species – M. palaeojavanicus. This conclusion was revised in 1989, when Kramer concluded that the size was within the size range of H. erectus.

Sangiran 7

Dating to between 1.51 and 1.6 million years of age, Sangiran 7 (comprising 54 teeth) was recovered from 1937 to 1941. Fred Grine analysed some of the teeth in 1984, but it would be a decade later before he revised his earlier conclusion that they were hominin. As a result, three teeth FS 67, 72 and 83 were re-attributed to Pongo sp.

Wilfrid Le Gros Clark (1895 – 1971)

Sangiran 8

Uncovered in 1952, Sangiran 8 comprises fragment of mandible, with some teeth roots intact and a complete third molar crown. This individual is interpreted to have died in the jaws of a crocodile, based upon the scare marks on the fossil. The fossil was first described in 1953 by P. Marks concluding it lay outside the size range of H. erectus. In 1955, Le Gros Clark concluded that the fossil was within the range of H. erectus and that has remained the official attribution for Sangiran 8 ever since.

Sangiran 27

This partial adult cranium was first found in 1978 near Sangiran village, north of the River Chemoro and it was found as construction was underway on a new dam. The skull was found in the upper levels of the Sangiran Formation dating to between 1.66 and 1.58 million years of age. The fossil was described by Teuku Jacob in 1980, in which he attributed it to Meganthropus but was taxonomically revised in 2008 for reasons similar to the taxonomic revision of Sangiran 8. Indriati and Anton (2008) also noted that hyper-robust features of the fossil reflects earlier representatives of H. erectus.

Modern Uses of Meganthropus

Though taxonomically and scientifically redundant, Meganthropus is used by pseudoscientific Creationists as evidence for the Nephilim, giants that lived before Noah’s flood, referenced from an Iron Age manuscript called the “Book of Enoch”.

Norandino and Lucina Discovered by the Ogre (1624) – Giovanni Lanfranco (1582 – 1647)

A trickle of scientific papers and posters have been published and presented over the decades, claiming evidence for Meganthropus. Authors have suggest that Sangiran 5 is evidence of the existence of an older, “more robust morph”, with pongo-like characteristics. Suggesting that a Gigantopithecus-like counterpart lived in island South-East Asia. The most recent appearance of support for Meganthropus was at the 83rd annual meeting of the American Association of Physical Anthropologists in 2014, a team of scientists led by Clement Zanolli presented a poster on their analysis of a fossil mandible fragment code named Arjuna 9. They suggested that teeth had enamel thickness and dental tissue proportions that differed from those seen in H. erectus. The statistical analysis of the enamel-dentine junction also seemed to support an attribution to Pongo sp. The fact remains, no evidence exists to support classifying the Javan fossils as Meganthropus.

Abel Lived 3.5 Million Years Ago Along The Shores of Megachad – Australopithecus bahrelghazali

On the 23rd of January 1995, a team of palaeontologists discovered a fragment of fossil jaw lying on the gravel desert of northern Chad. The fossil could not be accurately dated, nevertheless stratigraphic layers nearby suggested it could be around 3.5 million years of age. Back then, the site of Koro Toro was on the edge of africa-11117a 3 million square kilometre Lake called Megachad. The fossil, now codenamed KT 12/H1 consisted of the front portion of the jaw with a number of teeth still in place. By using Isotopic analysis the diet of the hominin shortly before it died, can be determined. The fossil showed a preference for C4 plants, including sedges and grasses, suggesting that the area around Koro Toro was predominantly grassland. Comparing the fossil to other hominins, the features were considered very different compared to Australopithecus afarensis, 2,500 km away in Ethiopia and Kenya. The French team, led by Michel Brunet, concluded the fossil was part of a new species of AustralopithecusAustralopithecus bahrelghazali. This caused a bit of a stir in the palaeoanthropological community, but progressively began to die down. The lack of fossil finds in Chad thereafter contributed to the rate at which the palaeoanthropological community forgot about the fossil, that was, until 2001. Given the same variety of animals can be found in both Ethiopia and Chad, it is not a stretch to imagine australopithecines travelling between the two regions three million years ago and many palaeoanthropologists now consider the fossil, a variant of Australopithecus afarensis.

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KT12/H1 the holotype of Australopithecus bahrelghazali

How did the fossil make palaeoanthropologists rethink their understanding human evolution? “Abel” as the fossil became to be known reminded palaeoanthropologists that human evolution could have been more complex than previously accepted. Though once you considered the features of an Australopithecus afarensis jaw and compare that to “Abel”, it is acceptable to attach it to the Ethiopian hominin. The differences are subtle. It is worth reminding here however that the use of species names don’t tell us much about the hominins palaeobiology, are primarily to put, order to our understanding of evolution and are a useful means of scientific communication. Palaeoanthropology has had a long history of naming new species, when later we realize we were too optimistic. In the sense, that we forget how useless this venture is. More is learned from the fossils, about a hominins diet, locomotion patterns and physical characteristics than what species it belongs too. Thankfully, science is less focused on this and we are now learning much more about the hominin and the ecosystem it was once a part of. The second way in which “Abel” got us thinking, was via the surprise geographic location. Up until that time, any fossil finds made on the continent of Africa were made exclusively in eastern and southern Africa. “Abel”, reminded us that hominins were not just restricted to those regions and likely could be found all over Africa. Exciting though this prospect was, it could not solve the problem of preservation in areas where fossils cannot survive, in the hostile environments of the Sahel.

donkey-534906
A Gravel Desert in Tunsia

Eventlog – 15th of January 1942 – Dawn and Demise of Meganthropus palaeojavanicus

The History of Palaeoanthropology is dominated by an obsession of applying new latin genus and species names to nearly every fossil that made its way into scientific scrutiny. With the passing of the 20th century, this obsession dissipated as scientists began to realise such preoccupations were redirecting some much needed attention away from many important relevant questions. Today’s Eventlog reminds us of what had been. But first let me introduce three gentlemen.

W. C. B. Koolhoven was a Dutch Director of the Geological Survey of the Netherlands Indies. Franz Weidenreich (1873-1948) was a german anatomist and palaeoanthropologist, based for much of his life in Beijing, China and had a long association with the Homo erectus fossils of Zhoukoudian, China. Finally, let me introduce Gustav Heinrich Ralph von Koenigswald (1902-1982) a german palaeontologist, geologist and Palaeoanthropologist. Interested in geology and fossils from a young age, Gustav vonKoenigswald worked in Java propecting for hominin fossils. The Dutchman and two germans crossed paths in discussions about two Javan fossil mandibles. The debate centred around the size of the mandibles, which at that time seemed too big to be attributed to Homo erectus.

And so on this day the 15th of January 1942, Koolhoven wrote a letter to Weidenreich letting him know that vonKoenigswald was keen to attribute Sangiran 5 and 6a to Meganthropus palaeojavanicus. It would be eight years before vonKoenigswald would introduce the new genus and species formally. Over the next few decades, M. palaeojavanicus began its slow dissolution from scientific discourse, replaced by the hominin Homo erectus.

Discovery of the Paranthropus of Peninj

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.

Gorjanović-Kramberger Hypothesis: Took 99 Years, But We Finally Tested It

You meet Homo neanderthalensis in a dark alley……………….What do you do?

Homo neanderthalensis is one of the best understood species of hominin today. One that lasted many hundreds of thousands of years throughout Europe. Despite what we know through the lens of science, there is still much that we want to know about this species of human. Interrogating the subtle pieces of evidence is the task of palaeoanthropologists, archaeologists, palaeoenvironmental scientists throughout the world. Contrary to what you may see on your average human evolution documentary, the kind of research conducted can be much more subtle. Here I will draw your attention to a difficult question. If we could fill the Great Hall of the South Kensington Museum with a few hundred individuals of our extinct cousin, what differences would we see in the upper chest and neck. The answer to that, at the beginning of 2015: We are not happy that we really know enough to give an answer.

Range_of_Homo_neanderthalensis
Range of Homo neanderthalensis

H. neanderthalensis is a well represented species of human in the fossil record, but the post-cranial anatomy is less well accounted for than the skulls. Not ideal for an investigation into the chest and abdominal regions of the human body. Nevertheless, it is vital we exhaustively examine what we have, to reveal potential clues to the kind of morphology these populations once exhibited. To that end, ten palaeobiologists from various Spanish academic institutions presented evidence that may be useful here. The mechanics of the breathing system, constrained by the rib cage and not the evolution of the species, is the focus here. Research continues to be a work in progress, new technologies arrive and they help further our understanding of the past. This research is no exception. Two year into the new millennium a new form of analysis that gauged quantity within a structure was applied to a collection of isolated ribs from an individual codenamed Shanidar 3. This individual had a more splayed lower rib cage compared to the more barrel-like form of our lower rib cage. Thus started a series of papers that suggested the lower rib cage of Homo neanderthalensis was generally less like ours. Comparatively less investigative research has been given to the upper end of the rib cage. This latest academic paper sets out to help understand just that.

Title and Authors of the Paper in Question
Title and Authors of the Paper in Question
640px-Krapina_-_Dragutin_Gorjanovic_Kramberger
Dragutin Gorjanović-Kramberger (1856 – 1936)

In 1906 and a time when ancient humans were Anti or Post Diluvian Era (Noah’s Great Flood), Dragutin Gorjanović-Kramberger suggested that the superior ribs are an important facet of an upper thoracic orchestra of components, that together control upper thoracic breathing, separate from diaphragmatic breathing. It was not until 2015 that this hypothesis was put to the test on six hominin first-ribs from the cave site of El Sidrón, Asturias, northern Spain. The six first-rib fragments may represent, at most, four individuals. The first step was to identify the bone fragments and place them in their correct anatomical position. Below is a re-organisation of the information given about the sample itself. The first-rib of Kebara 2 was found to be similar in shape space and form space (both terms used in a statistical analysis of shape, known as Procrustes Least Squares (PLS)) to SD-1767 and SD-1699, indeed H. neanderthalensis exhibits straighter first-ribs than modern day Homo sapiens. What could this mean? The scalene muscles are the ones that give your neck, its shape. They run from the Rib 1 and Rib 2 up the side of your neck attaching to the vertebrae. Alteration in shape of the first ribs, and the attached muscles will have to operate differently, but may help explain the differences we see between H. sapiens and H. neanderthalensis. The principle component analysis (PCA) reveals some overlap in the linearity of the rib shaft. Such results are reflected in analysis of the specimens of Krapina Cave, Croatia and ATD6-108 representing Homo antecessor, from Gran Dolina Cave, Atapuerca, Spain. So, the straightness of the first-ribs may affect the movement of the upper torso during breathing.

Juvenile 1: SD-2148 (Right) and SD-2172 (Left)

Juvenile 2: SD-417 (Left) and SD-1225 (Right)

Large Adolescent / Small Adult: SD-1767 (Left)

Large Adult: SD-1699 (Right)

Looking at the juveniles, it is important to understand costal cartilage development. Understanding adult H. neanderthalensis individuals is easier, as there are more post-cranial fossils, but the El Sidrón hominins will be useful in understanding the ontogeny of costal cartilage in future fossil ribs of  juveniles. The El Sidrón juveniles confirm a tighter upper chest for H. neanderthalensis. The first-ribs are smaller, but feature larger attachments at the rib heads, whereas the lower ribs have smaller attachment points. Therefore, a H. neanderthalensis individual, exhibited a smaller upper torso, which was further from the cranium thanks to the slightly longer neck vertebrae. First-ribs that are straighter would have to project out from the skeleton more and Gorjanović-Kramberger proposed that the rest of the rib-cage would project outward, just as much. The scientific team added to this, that a change in the first ribs would in turn affect the rest of the rib-cage, because the ribs are latched together with intercostal muscle, preventing individual ribs from varying in shape, that ultimately allows coordination of muscle, chest wall and breathing action. Upper ribs connect directly with the sternum and so, result in distinctive rib shape compared with the lower thorax.

Association of Intercostal Muscle and Rib Bone
Association of Intercostal Muscle and Rib Bone

To summarise, the first ribs appear to determine the shape of the upper thorax ribs, but straightness of the first rib is linked with the straightness of the upper ribs. Together, this suggests the existence of different rib shape and functions between the upper and lower thorax. When you look at a particular fossil specimen, it is important you are aware of what bones, muscles, cartilage was associated with it. They all interact in subtle ways which we are piecing together in hominins, with the variety in body forms available going back 7 million years. In examination of the monophyly of Paranthropus, cladistical statistics showed us that the skeletal points used, should not be linked with eachother. An example of that, would be the masticatory system in Paranthropus comprising numerous points, all interacting with one another. This is a shame because the crania and mandibles are predominantly all we have of that genus. Currently, most are happy that Paranthropus boisei, Paranthropus aethiopicus and Paranthropus robustus are part of the same family – they are monophyletic. The rib cage, is similar to the masticatory system but it is a single unit with two functions, one  is upper thoracic respiration and the other is diaphragmatic respiration. H. neanderthalensis evolved a more restrictive respiratory system and highly developed arm muscles, evolutionarily more important for the condition in which it lived. So, if you were to meet our ancient ancestor in a dark alley, what should you do? It would have been prone to breathlessness, but could rearrange your face easier. Moral of the story, RUN!

The costal remains of the El Sidrón Neanderthal site (Asturias, northern Spain) and their importance for understanding Neanderthal thorax morphology

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