All posts by Adrian Evans

New mini-project – August 2016

This field season we are trying something new. We have identified a small area and created a mini-project. We have also revised the identification workflow on fossilfinder to make the questions more relevant to the problems we have. While we are in the field we will be surveying along this small area and interacting with the fossilfinder forum by visiting and identifying problem objects along with the interesting things that are being found.

Hopefully you will join in and help classify this area while we are still here in the field.

Our aim is to be able to directly compare very diligent field survey with the new virtual survey methods that are created through citizen science

New species of Homo discovered in South Africa

Today the discovery of a new species in our primate lineage has been announced. Homo naledi is the new name for the species, marking its assignment as a close ancestral species. This find is based on the discovery of more than 1500 specimens from Rising Star Cave near Johannesburg in South Africa.

Two articles have been published on the finds. The first describing the new species and the second describing the context of its discovery.

Is there more to the genus Homo than we think?

Almost 300 years ago, Linnaeus defined our genus Homo (and its species Homo sapiens) with the noncommittal words nosce te ipsum (know thyself). Since then, fossil and molecular biology studies have provided insights into its evolution, yet the boundaries of both the species and the genus remain as fuzzy as ever, new fossils having been rather haphazardly assigned to species of Homo, with minimal attention to details of morphology.

A paper published in today’s issue of science magazine by Jeffrey Schwartz and Ian Tattersall argues that, historically, fossil specimens have been “shoehorned” into Homo species “without regard to their physical appearance”. They overview recent examples of debate to illustrate significant differences in the ways that researchers are willing to group specimens. They also picture several fossil specimen examples of homo to highlight marked differences between them. The paper calls for a revisit of criteria for species recognition. The reason being that historical classification schemes, and subjective assignment of new fossils, may be limiting how we can build testable models of human evolution.

The Science perspectives paper can be found here: “Defining the genus Homo.” Science 28 August 2015: Vol. 349 no. 6251 pp. 931-932 DOI: 10.1126/science.aac6182

1984: The discovery of Nariokotome Boy

This skull and mandible belong to the 1.6 million year old skeleton of Homo erectus found at Nariokotome on the west side of Lake Turkana, sometimes referred to as the “Turkana Boy” or the “Nariokotome Boy”. This discovery was made by Kamoya Kimeu, on a Sunday morning in August 1984. He was walking up a gentle slope on the southern side of the seasonal Nariokotome River when he spotted a matchbox sized skull fragment, which he recognized as belonging to a human ancestor. No one could have imagined that such a complete specimen would be recovered. As the excavation of the hillside progressed more pieces of skull, teeth, and then ribs began to be uncovered. This turned into one of the most exciting excavations of arguably the most important fossil discovered in east Africa.
Due to its completeness, this skeleton provides unprecedented insight into the body shape, brain size and development of Homo erectus. The Turkana Boy was surprisingly tall, 5’3” (1.6 meters) although he was still an adolescent. He had a slender body well adapted to living in hot climates. Homo erectus was the first human ancestor to migrate out of Africa 1.8 million years ago. Several specimens have also been recovered from sites in China, Indonesia, and Dmanisi in the Republic of Georgia.

A 3D scan of this fossil and others can be found at africanfossils.org

Earliest modern human-like hand bone found in Tanzania

Modern humans are characterized by specialized hand morphology that is associated with advanced manipulative skills. Thus, there is important debate in paleoanthropology about the possible cause–effect relationship of this modern human-like (MHL) hand anatomy, its associated grips and the invention and use of stone tools by early hominins. Here we describe and analyse Olduvai Hominin (OH) 86, a manual proximal phalanx from the recently discovered >1.84-million-year-old (Ma) Philip Tobias Korongo (PTK) site at Olduvai Gorge (Tanzania). OH 86 represents the earliest MHL hand bone in the fossil record, of a size and shape that differs not only from all australopiths, but also from the phalangeal bones of the penecontemporaneous and geographically proximate OH 7 partial hand skeleton (part of the Homo habilis holotype). The discovery of OH 86 suggests that a hominin with a more MHL postcranium co-existed with Paranthropus boisei and Homo habilis at Olduvai during Bed I times.

http://www.nature.com/ncomms/2015/150818/ncomms8987/full/ncomms8987.html

Basalt

Basalt is a volcanic igneous rock with a crystaline structure. It forms when lava rapidly cools.

It can be hard to distinguish from sandstone, especially when weathered, as certain types are lighter brown in colour.

However, its crystaline structure and hardness mean that broken pieces retain sharper angular edges than sandstone and it has a more reflective look to it. The crystaline structure can often be seen on broken surfaces. Basalt is often quite black in colour but can be different shades of brown.

examples of basalt rock
examples of basalt rock

Ground Truthing the FossilFinder Beta Test

We arrived yesterday in Ileret and the first thing we just had to do was to see if we could relocate finds located by our beta testers from the images we collected last season.

One of the pictures we placed online during the beta was flagged a few times as containing numerous fossil bone fragments. Here is the picture from the preview:

An interesting image from the fossilfinder beta
An interesting image from the fossilfinder beta

GPS in hand we drove out to area 8. After a few moments of figuring out the best way to use the gps data we had we found those fossil bones on the surface:

fossil bones found during ground truthing
fossil bones found during ground truthing

This is an excellent result and means that our method is working!