---
title: Homo Rudolfensis
author: Emma Groeneveld
source: https://www.worldhistory.org/Homo_Rudolfensis/
format: machine-readable-alternate
license: Creative Commons Attribution-NonCommercial-ShareAlike (https://creativecommons.org/licenses/by-nc-sa/4.0/)
updated: 2023-04-25
---

# Homo Rudolfensis

_Authored by [Emma Groeneveld](https://www.worldhistory.org/user/emmagroeneveld1/)_

*Homo rudolfensis* is an early human species that lived in East [Africa](https://www.worldhistory.org/disambiguation/africa/) between c. 2.5 and 1.8 million years ago. It is known from a handful of skull, jaw and teeth fragments that remind alternatingly of *Homo* or of *Australopithecus* and that piece together to reveal a relatively large-brained, flat-faced species with robust teeth capable of chewing through tough plants.

The associated dates mean that *Homo rudolfensis* was around at a time that saw the emergence of our genus of *Homo* – a time still very much shrouded in mystery as the fossil remains are scarce, and thus, successfully building jigsaw puzzles with said remains is very difficult. This is reflected in debates that rage regarding the relationship between *Homo rudolfensis* and its close contemporary, *[Homo habilis](https://www.worldhistory.org/Homo_Habilis/)*, and the fact that some scientists favour lumping both into one species instead. It is moreover unclear whether *Rudolfensis* and *Habilis* have indeed reached their proper place within *Homo*, or whether they might fit better within *Australopithecus* instead.

### Discovery

East Africa was a pivotal stage for the early years of human species, and palaeoanthropologists Louis and Mary Leakey and their sons played a central role in its discovery as such. Already in the 1950s, their efforts at Olduvai Gorge in Tanzania had uncovered early stone tools belonging to what they termed the Oldowan industry, and in the 1960s, their son Jonathan found bones and bone fragments that the Leakey team assigned to the then-new species *Homo habilis*, which became the earliest member of the genus of *Homo* known at the time.

A research project that focused its attention on northern Kenya, along the shores of Lake Turkana, would further change the picture of early *Homo*. Richard Leakey – Louis and Mary's son – led fieldwork there in the 1970s, and in 1972, at Koobi Fora, one of his team members, Bernard Ngeneo, discovered an interesting collection of skull fragments.

Once pieced back together, the face that greeted the team was striking: it had a steep forehead, a flat face, and a wide palate – seemingly a mixture of *Homo* and *Australopithecus* features that did not match anything else known at the time.

The skull, known scientifically as KNM-ER 1470, was initially dated to c. 2.4 million years old (later adjusted to c. 1.8 million years in 1989, and then to c. 2 million years in 2013) and assigned by Richard Leakey first to an indeterminate *Homo* species but then to *Homo habilis*. However, since the skull's features differed quite a bit from known *Homo habilis* specimens and its cranial capacity was larger, it sparked a whole lot of bickering and arguing in the scientific community.

Already in 1978, only two years after Leakey assigned the skull to *Homo habilis*, the Russian scientist Valerii Alexeev proposed giving the new skull the lead role in its own species, instead, naming it *Homo rudolfensis* (after Lake Turkana's old name, Lake Rudolf). However, the English version of Alexeev's paper did not appear until 1986, and, since not much data was put forth, the species name of *Homo rudolfensis* was not accepted by the scientific community until the early 1990s. Even so, the debate has continued, though, just like *Homo habilis*, *rudolfensis*' mixture of features does not make it a clear match with either *Homo* or *Australopithecus*.

### Appearance

Besides the KNM-ER 1470 skull, we have a few other clues that allow us to piece together what its face would have looked like, though not its body; no bones belonging to body parts other than the skull have been solidly attributed to *Homo rudolfensis*. More skull and jaw fragments were found at Koobi Fora, near where KNM-ER 1470 was discovered, while teeth were discovered in the Omo river basin in Ethiopia, and a jaw was found in the Chiwondo Beds in Malawi. The material dates to between 2.5-1.8 million years ago, marking it as a direct contemporary of *Homo habilis* (dated to between c. 2.3 million and 1.5 million years ago).

[ ![Homo Rudolfensis Skull (KNM-ER 1470)](https://www.worldhistory.org/img/r/p/750x750/17316.jpg?v=1682498380-1682498387) Homo Rudolfensis Skull (KNM-ER 1470) Ryan Somma (CC BY-SA) ](https://www.worldhistory.org/image/17316/homo-rudolfensis-skull-knm-er-1470/ "Homo Rudolfensis Skull (KNM-ER 1470)")What greets us is a species with a larger brain case, flatter face, and larger teeth than *Homo habilis*. Its forehead is fairly steep and leads to a domed skull – both characteristics of the genus *Homo*. The brain that sits beneath this domed skull comes in at an estimated 752 cm³, although a 2008 study led by Timothy Bromage suggests reducing this to 700 cm³ instead (which is still a whole lot larger than general *Australopithecus* brain sizes which tend to come in between 387 and 560 cm³). Reminding us instead of *Australopithecus* is the fact that the middle of *Homo rudolfensis*' face is broader than the upper part and that the palate which sits below is shallow, broad, and short. Its canines and incisors are large, and its molars show more relief than what can be seen in *Australopithecus*.

From the few skeletal bones that are sometimes mentioned in connection with *Homo rudolfensis*, only one, at this point in time, seems capable of earning the 'maybe' label: KNM-ER 1472, a femur from Koobi Fora dated to c. 1.9 million years ago. It is normally attributed to *Homo habilis* but since it is quite a bit larger than any other *Homo habilis* femurs, it does not sit quite right and might fit better within *Homo rudolfensis*, instead. However, this has merely been suggested by some researchers and has not been widely accepted.

### Classification Caveats

Despite the above-mentioned differences between the skulls of *Homo rudolfensis* and *Homo habilis*, the fragmentary nature of material belonging to early *Homo* species dating to this time (c. 2.5-1.5 million years ago) leads to a bit of a jumble when it comes to classifying this material, even if differences can be observed. The relationships between the various suggested species around this time, as well as who their ancestors were, are still poorly understood. Since we do not have much fossil material assigned to *Homo rudolfensis*, it becomes quite difficult to make assumptions about the species as a whole, as some variation within species is to be expected.

This is why to this day, researchers have not all managed to agree on whether to keep *Homo* *rudolfensis* and *Homo habilis* as two separate species or lump them both together into one, more varied species. In the latter case, the KNM-ER 1470 skull and other skull fragments normally assigned to *Homo rudolfensis* would then be seen as the males of the species, whereas the smaller skulls normally assigned to *Homo habilis* could be females. Differences in size and appearance between males and females – sexual dimorphism – is common in a lot of animals and likely occurred in early *Homo*, too. However, as archaeologist Manuel Will notes, trying to assess the sex of such highly fragmentary remains is nearly impossible, and there is no reason to expect grouped fossils to show systematic bias towards any sex. At this point in time, most scientists are in favour of upholding the separation between the two species, although they do not all agree on exactly which specimens should be assigned to which species.

Because of its interesting mix of features reminding alternatingly of *Homo* and of *Australopithecus*, there is disagreement about whether *rudolfensis* deserves its place within the genus *Homo*, or whether it would fit better within *Australopithecus*. The same question applies to *Homo habilis*, too. While most scientists back the current status of both – in *Homo*, at the base of the *Homo* tree – it does stretch the definition of *Homo* a bit. However, the same can be said if *rudolfensis* and *habilis* were to be added to *Australopithecus*. A third option has even been suggested for *rudolfensis*: anthropologist David Cameron feels it fits within *Kenyanthropus*, an older genus whose only known species, *Kenyanthropus Platyops*, lived a little over 3 million years ago. However, other scientists have deemed this option as unwarranted at present.

It is clear that early *Homo* (or late *Australopithecus*) is a bit of a mess. Hope is on the horizon, though: in recent years, many new, important discoveries have been made when it comes to early humans, and, if more *Homo rudolfensis* material were to be found, we will be better able to connect the dots regarding its ancestry and place in the broader evolutionary story.

[ ![Hominin Skulls](https://www.worldhistory.org/img/r/p/500x600/17152.jpg?v=1678269603-1678269622) Hominin Skulls Ryan Somma (CC BY-SA) ](https://www.worldhistory.org/image/17152/hominin-skulls/ "Hominin Skulls")### Habitat & Diet

Even if there is a lot we do not know about *Homo rudolfensis*, at least the locations where remains that are normally assigned to this species have been found – the Chiwondo Beds in the Malawi Rift in northern Malawi, Koobi Fora in Kenya, and the Omo river basin in Ethiopia – might be able to tell us something about its habitat(s), diet, and way of life. Furthermore, since early *Homo* is at present such a jigsaw puzzle lacking far too many pieces, and because there is so much discussion about which material to assign to which species, it is worth looking at the overall collection of early *Homo* fossils. Early *Homo* specimens dating between c. 2.8 and 1.6 million years ago are known from other places such as Hadar in Ethiopia, Chemeron as well as West and East Turkana in Kenya, Olduvai in Tanzania, and Sterkfontein, Swartkrans, and Drimolen in South Africa.

Between c. 2.8 and 2.5 million years ago, the African climate changed and saw the development of swathes of open woodland and grassland savannah containing plants better adapted to cooler, more arid conditions. Researchers argue that these conditions would have favoured species with bigger, more robust teeth, as they could more successfully chomp down on tougher, more fibrous fruit, leaves, and grasses. *Homo rudolfensis*, with its relatively large molars (though not as large as those of, for instance, robust *Australopithecines* such as *Paranthropus boisei*), would have been at least decently adapted to deal with such foodstuffs.

At the same time, there were fast and extreme environmental shifts that would have required flexibility in order to survive. In East Africa, tropical forests clung on even through periods of droughts, and we know that *Homo rudolfensis* also survived in the relatively cool and wet wooded savannah that was the Malawi Rift around 2.4 million years ago where it ate so-called C3 plants. All in all, the data points to early *Homo*, including *rudolfensis*, having been dietary generalists that were able to survive in various kinds of habitats. Even so, differences in tooth wear between *Homo rudolfensis* and *Homo habilis* indicate they likely had different diets.

[ ![Lake Turkana, Kenya](https://www.worldhistory.org/img/r/p/750x750/6117.jpg?v=1639132205) Lake Turkana, Kenya Doron (CC BY-SA) ](https://www.worldhistory.org/image/6117/lake-turkana-kenya/ "Lake Turkana, Kenya")We know that Homo habilis used tools, as tools of the so-called Oldowan tool industry have been found alongside *Homo habilis bones*. Although *Homo rudolfensis* is not directly associated with any tools, [Oldowan tools](https://www.worldhistory.org/Oldowan_Tools/) date to between 2.6 and 1 million years ago and thus overlap not just with *Homo habilis* but also with *Homo rudolfensis* and *[Homo erectus](https://www.worldhistory.org/Homo_Erectus/)*, as well as with late *Australopithecines*. It is certainly possible that all of these may have used stone tools to some varying extent. Most scientists agree that *Homo* was probably the more habitual toolmaker of this bunch. Oldowan tools were made by striking flakes off a stone core with another stone and may have been used for such things as butchering, woodworking, cutting, digging, and cracking (bones, to get at the marrow, or skulls to retrieve the brain). These may have been activities that played a role in *Homo rudolfensis*' lives. Neighbours of *Homo rudolfensis* during its time on this earth would not just have been *Homo habilis* but also *Paranthropus boisei*, *Australopithecus africanus,* and *Homo erectus*.

### Conclusion

It is clear by now that *Homo rudolfensis* can be used as a perfect illustration of the little we know definitively about the early days of the genus of *Homo* (or the late days of *Australopithecus*). Like *Homo habilis* – its close contemporary and main partner when it comes to featuring in classification debates – the few *Homo rudolfensis* remains we have unearthed so far show an interesting mix of both *Homo* and *Australopithecus* features. Though there are certainly differences between *Homo rudolfensis* and *Homo habilis*, the ongoing debate about whether this may simply be due to variation within a species may only be put to rest conclusively if we find more fossils.

However, the past decade or so of palaeoanthropology has shown that the story of hominin evolution is growing increasingly complex and fluid. We know from DNA retrieved from more recent species such as [Neanderthals](https://www.worldhistory.org/Neanderthal/) and [Denisovans](https://www.worldhistory.org/Denisovan/) that interbreeding within species would likely have been the norm rather than the exception, at least during those times. As such, hominins weaved in and out of contact with each other and influenced each other's evolutionary pathways, like a braided stream (rather than a strict evolutionary tree in which the branches never rejoin each other after branching off). The same may very well be true for the earlier, multifaceted time in which late *Australopithecus* and early *Homo*, including *Rudolfensis*, lived.

#### Editorial Review

This human-authored definition has been reviewed by our editorial team before publication to ensure accuracy, reliability and adherence to academic standards in accordance with our [editorial policy](https://www.worldhistory.org/static/editorial-policy/).

## Bibliography

- Antón, Susan C. "Early Homo : Who, When, and Where." *Current Anthropology*, Volume 53, Number S6, December 2012, pp. 278-298.
- Argue, Debbie. "Homo rudolfensis." *Encyclopedia of Evolutionary Psychological Science*, edited by T.K. Shackelford, V.A. Weekes-Shackelford (eds.). Springer, 2017, DOI 10.1007/978-3-319-16999-6\_3434-2.
- [Bolus, Michael. "Dispersals of Early Humans: Adaptations, Frontiers, and New Territories." *Handbook of Paleoanthropology*, edited by Henke, Winfried & Ian Tattersall. Springer, 2015, 2374.](https://www.worldhistory.org/books/3642399789/)
- Bromage, Timothy G. e.a. "Craniofacial architectural constraints and their importance for reconstructing the early Homo skull KNM-ER 1470." *Journal of Clinical Pedriatic Dentistry*, 33(1), 2008, pp. 43-54.
- [Case Study: Koobi Fora Research Project](https://education.nationalgeographic.org/resource/case-study-koobi-fora-research-project/ "Case Study: Koobi Fora Research Project"), accessed 24 Apr 2023.
- [Collard, Mark, and Bernard Wood. "Defining the Genus Homo." *Handbook of Paleoanthropology*, edited by Henke, Winfried & Ian Tattersall. Springer, 2015, 2107-2144.](https://www.worldhistory.org/books/3642399789/)
- Dunsworth, H. M. "Origin of the Genus Homo." *Evolution: Education and Outreach*, 3, 2010, pp. 353–366.
- Fleagle, John G. and Frederick E. Grine. "The Genus Homo in Africa." *The Cambridge World Prehistory. Volume 1: Africa, South and Southeast Asia and the Pacific*, edited by C. Renfrew and P. Bahn (eds.). Cambridge University Press, 2014, 87-88.
- [Hawks, John: https://johnhawks.net/weblog/should-there-be-a-new-genus-to-contain-homo-habilis/](https://johnhawks.net/weblog/should-there-be-a-new-genus-to-contain-homo-habilis/ "Hawks, John: https://johnhawks.net/weblog/should-there-be-a-new-genus-to-contain-homo-habilis/")
- [Kimbel, William H. "The Species and Diversity of Australopiths." *Handbook of Paleoanthropology*, edited by Henke, Winfried & Ian Tattersall. Springer, 2015, 2085.](https://www.worldhistory.org/books/3642399789/)
- Leakey, M., Spoor, F., Dean, M. et al. "New fossils from Koobi Fora in northern Kenya confirm taxonomic diversity in early Homo." *Nature*, 488 (2012), pp. 201–204.
- Lüdecke, T. e.a. "Dietary versatility of Early Pleistocene hominins." *PNAS*, 115 (52), December 2018, pp. 13330-13335.
- Prat, Sandrine. "Emergence of the genus Homo: From concept to taxonomy." *L'Anthropologie*, Volume 126, Issue 4, September–October 2022, p. 103068.
- [Schrenk, Friedemann, Ottmar Kullmer, and Timothy Bromage . "The Earliest Putative Homo Fossils." *Handbook of Paleoanthropology*, edited by Henke, Winfried & Ian Tattersall. Springer, 2015, 2145-2165.](https://www.worldhistory.org/books/3642399789/)
- [Strait, David, Frederick E. Grine, and John G. Fleagle. "Analyzing Hominin Phylogeny: Cladistic Approach ." *Handbook of Paleoanthropology*, edited by Henke, Winfried & Ian Tattersall. Springer, 2015, 2000-2006.](https://www.worldhistory.org/books/3642399789/)
- Tattersall, I. "Classification and phylogeny in human evolution." *Ludus Vitalis*, 9 (15), 2019, p. 140.
- [Toth, Nicholas, and Kathy Schick. "Overview of Paleolithic Archaeology." *Handbook of Paleoanthropology*, edited by Henke, Winfried & Ian Tattersall. Springer, 2015, 2448.](https://www.worldhistory.org/books/3642399789/)
- Ungar, Peter S. "Dental Evidence for the Reconstruction of Diet in African Early Homo." *Current Anthropology*, Volume 53, Number S6, December 2012, pp. 318-329.
- Ungar, Peter S., Frederick E. Grine, and Mark F. Teaford. "Diet in Early Homo: A Review of the Evidence and a New Model of Adaptive Versatility." *Annual Review of Anthropology*, Vol. 35, 21 September 2006, pp. 209-228.
- [Van Couvering, John A. . "Quaternary Geology and Paleoenvironments ." *Handbook of Paleoanthropology*, edited by Henke, Winfried and Ian Tattersall. Springer, 2015, 552.](https://www.worldhistory.org/books/3642399789/)
- Wood, B. "Human evolution: fifty years after Homo habilis." *Nature*, 508, 2014, pp. 31-33.
- Zanolli, C. e.a. "The internal structural organization of the post-canine dentition of the initial Early Pleistocene HCRP-U18-501 hominin mandible from Malawi." *East African Association for Paleoanthropology and Paleontology (EAAPP) Seventh Biennial Conference*, Seventh Biennial Conference, Nairobi, Kenya, October 2019.

## About the Author

Emma Groeneveld studied History & Ancient History, focusing on topics such as Herodotus and the juicy politics of ancient courts. Since the conclusion of her studies in 2015, she has been spending more and more time on her obsession with prehi
- [Linkedin Profile](https://www.linkedin.com/in/emma-groeneveld-31a39b93/)

## Timeline

- **c. 2600000 BCE - c. 1000000 BCE**: Oldowan tool industry.
- **c. 2600000 BCE - c. 12000 BCE**: The Pleistocene epoch, ranging from c. 2,6 million years ago until c. 12,000 years ago. It is characterised by repeated cycles of glacials and interglacials.
- **c. 2500000 BCE - c. 1800000 BCE**: Known timespan within which fossils attributed to [Homo rudolfensis](https://www.worldhistory.org/Homo_Rudolfensis/) fall.

## Questions & Answers

### Are Homo habilis and Homo rudolfensis the same species?
At this point in time, most scientists are in favour of upholding the separation between Homo habilis and Homo rudolfensis. Some scientists do argue they should instead be lumped together into one, more varied species, however, but this is not the majority view.

### What did Homo rudolfensis eat?
Homo rudolfensis were dietary generalists that ate a variety of foodstuffs, including C3 plants. Because of their fairly robust molars, they would have been able to eat tougher, more fibrous fruit, leaves, and grasses.

### What does the name Homo rudolfensis mean?
The name of Homo rudolfensis refers both to its current place within the genus of Homo, as well as to the location where the first Homo rudolfensis specimen (the skull known as KNM-ER 1470) was found in 1972 at a site situated along the shores of Lake Turkana in Kenya, the old name of which was Lake Rudolf.


## Cite This Work

### APA
Groeneveld, E. (2023, April 25). Homo Rudolfensis. *World History Encyclopedia*. [https://www.worldhistory.org/Homo\_Rudolfensis/](https://www.worldhistory.org/Homo_Rudolfensis/)
### Chicago
Groeneveld, Emma. "Homo Rudolfensis." *World History Encyclopedia*, April 25, 2023. [https://www.worldhistory.org/Homo\_Rudolfensis/](https://www.worldhistory.org/Homo_Rudolfensis/).
### MLA
Groeneveld, Emma. "Homo Rudolfensis." *World History Encyclopedia*, 25 Apr 2023, [https://www.worldhistory.org/Homo\_Rudolfensis/](https://www.worldhistory.org/Homo_Rudolfensis/).

## License & Copyright

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