The key Olduvai Hominids

The following is the list of key hominids found in the Olduvai Gorge archeological sites. They are coded as OH nn (Olduvai Hominid number of fossil). The list is sorted by species and code. You can click on any pic to enlarge.

They are real treasures to understand the human origins in the last 2 million years. Don’t miss the bonus surprise at the end – Enjoy!

Homo habilis

OH 7 (1.7 Ma. Site FLK NN). It consists of 24 bones (parietal bones as most significant), teeth and mandible of a 10-12 year-old male. Discovered by the oldest son of Louis and Mary Leakey on his 20th birthday, it was thus nicknamed “Johnny’s Child”. It is the type specimen of the Homo habilis species.

OH 7 Homo habilis

OH 7 Homo habilis. Photo: Roberto Sáez

OH 8 (1.75 Ma. Site FLK N). It is the most complete Homo habilis foot found up to date. The bones are very similar to those of modern humans and demonstrate that the hominid was biped. It shows an intermediate morphology between Au. afarensis and H. erectus, facilitating a combination of arboreal and ground life. The surface of the bone shows incisive markings, which patterns, form and size indicate that they were probably left by a small crocodile.

OH 8 Homo habilis. Photo: Roberto Sáez

OH 13 (1.66 Ma). Nicknamed “Cinderella”, it is a collection of bones of a 16 year-old female: mandible, maxilla, several teeth, pieces of the cranial vault, and some postcranial elements.

OH 13 Homo habilis

OH 13 Homo habilis. Photo: The Evolution Fairytale

OH 16 (1.7 Ma). Nicknamed “George”, it is a quite complete cranium of a 15-16 year-old individual plus several teeth which are very large (close to australopitecines in size) and show caries on one side (very unusual in ancient specimens), which lead to differential chewing on the other side, causing it to develop a huge temporalis muscle on that side. It shows some key differences from Homo ergaster such as thinner bones, the supraorbital torus and the nuchal torus.

OH 16 Homo habilis. Photo: Wikipedia

OH 24 (1.8 Ma. Surroundings of DK site). A gracile female nicknamed “Twiggy” in honor of the famous, ultra-thin model from the 1970s. Due to sedimentary pressure, this fossil was considerably crushed but very complete. It provided important corroborating evidence for the validity of the Homo habilis species, defined with the type OH 7 found in 1960, 8 years before OH 24.

OH 24 Homo habilis

OH 24 Homo habilis. Photo: Roberto Sáez

OH 35 (1.8 Ma. Site FLK Zinj). It is a tibia that shows a pathology consistent with abnormal bone growth, known as heterotopic ossification, in the syndesmosis (reinforcement of the ligaments) between the tibia and the fibula. This was probably caused by a traumatic injury.

OH 35 Homo habilis

OH 35 Homo habilis. Photo: Roberto Sáez

OH 62 (1.8 Ma. Surroundings of Dik Dik Hill). It is a palate, some cranial fragments, a large part of the arm and fragments of both legs, in total 302 bone fragments. It is the first partial skeleton attributed to Homo habilis. These are key fossils to identify significant differences from Homo ergaster, particularly in respect to body size and bone weight. Initially it was believed that H. habilis was the predecessor species of H. ergaster. It has been determined that these two species coexisted for over 0.5 million years and have notable differences in both the cranium and post cranium, suggesting their likely occupation of distinct ecological niches.

OH 62 Homo habilis. Photo: Antropogenez.ru

OH 86 (1.84 Ma. Site PTK). Recently published, it is a proximal phalanx with a size and shape that suggest to be the earliest modern human-like hand bone in the fossil record. OH 86 was found close to the location of OH 7 (Homo habilis holotype) but -unlike OH 7- the morphology of OH 86 shows more modern features related to pad-to-pad precision gripping. This means, according to the researchers, that a different form of hominin could have co-existed with Paranthropus boisei and Homo habilis at Olduvai at that time.

OH 86. Photo: M. Domínguez-Rodrigo et al, Nature

Paranthropus boisei

OH 5 (1.75 Ma. Site FLK Zinj). It is the famous “Nutcracker Man” or “Dear Boy”, found in 1959 by the Leakeys after three decades of finding stone tools at this site of Olduvai Gorge, thus initially thought to be the creator of the tools. Only one year later they found the first remains of Homo habilis, likely the actual creator of the tools. Read here a full post describing OH 5.

OH 5 Paranthropus boisei. Photo: Roberto Sáez

OH 38 and OH 3 (1.2-1.4 Ma). Isolated incisors and molars which are the youngest remains associated with P. boisei species.

OH 38 Paranthropus boisei. Photo: Comprehensive Olduvai Database Initiative, CODI

OH 80 (1.34 Ma. Site BK). The first partial skeleton found in East Africa attributed to P. boisei, composed by several teeth, fragments of humerus, radius and femur. They represent a very robust individual (stature 152-160 cm, weight 40-61.7 kg). It also suggests sexual dimorphism when compared to possible female fossils (e.g. ER 1500). The dimensions of this hominid fall within the range of Homo erectus, although its morphology indicates biomechanical differences of the lower limbs. Its upper limbs are relatedly long and powerful. The radius is the most robust among the known samples in the Pliocene and early Pleistocene. It shows some characteristics suggesting a potential re-adaptation to climbing.

OH 80 Paranthropus boisei. Photo: Roberto Sáez

Homo ergaster

OH 9 (1.25 Ma. Site LLK). This was one of the first specimens of this species found in Africa, also being the oldest with a cranium capacity over 1000 cc. The very robust walls of the calvaria is a key characteristic differentiating this species from prior ones (H. habilis and australopitecines).

OH 9 Homo ergaster. Photo: Roberto Sáez

OH 28 (800-600 Ka. Site WK). A set of bone remains that were associated with Acheulean stone tools. They are the diaphysis of a femur and a coxal bone preserving part of the wing of the ilium, the acetabulum and the ischium. Very likely they all belonged to the same individual, a female.

OH 28 Homo ergaster. Photo: Roberto Sáez

Homo rhodesiensis

Ndutu (400 Ka). This skull has a cranial capacity that is slightly greater than the average of Homo ergaster, although it also falls within the range of Homo sapiens. Compared with Homo ergaster, it has more vertical parietal region and wider frontal region at coronal level, resulting in a lower post-orbital constriction. These features suggest a place in the same lineage that resulted in Homo sapiens.

Ndutu, Homo rhodesiensis. Photo: Roberto Sáez

And, who was the first Olduvai Hominid, OH 1?

In 1931 Louis Leakey started his research work at Olduvai Gorge, where he immediately found stone tools in abundance, as well as a very ancient but modern-looking skeleton (OH 1) in association with stone tools. However, it was soon discovered that OH 1 was the burial of a modern Maasai into older geological layers.

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3 thoughts on “The key Olduvai Hominids

  1. Pingback: Study: Chimps had herpes long before humans | Herpes Survival Kit

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