21/01/2016 by All Things AAFS!

Quick Tips: Archaeological Techniques –Use of Isotopes in Archaeology.

Isotopic analysis is widely used within the worlds of archaeology and anthropology. From analysing isotopes we’re able to uncover a wide range of information regarding the past; ranging from palaeoenvironments to palaeodiets, and even using isotopes to reconstruct trade routes of materials.

But first, what are isotopes?

All of the chemical elements consist of atoms which are specific to the element and the mass of an atom is dictated by the number of protons and neutrons it contains. The identity of the chemical element depends on the number of protons found within the atom’s nucleus, but the number of neutrons within the atom can vary. Atoms of the same chemical element (same number of protons), but with different masses, which is from the varying amount of neutrons, are called isotopes.

Within nature, most of the elements consist of a number of isotopes. These isotopes can be found within water, livestock, crops and plants, which can then be used to reconstruct palaeodiets and palaeoenvironments.

Within nature, most of the elements consist of a number of isotopes. For a great majority of elements these relative proportions of isotopes are fixed, but there are a group of elements which either due to chemical or biochemical processes are of variable isotopic composition. These elements are oxygen, carbon, nitrogen and sulphur. Another group of isotopes that are used for analysis are strontium, lead and neodymium. These are formed by elements which contain stable but radiogenic isotopes, which are formed by radioactive decay of another element. Carbon and nitrogen isotope composition are primarily used to reconstruct diets, and oxygen isotopes are used to determine geographic origin. Strontium and lead isotopes found within teeth and bone can sometimes be used to reconstruct migration patterns in human populations and cultural affinity

A table of the various elemental isotopes that are valuable in archaeological and anthropological research.

But how do isotopes get into skeletal remains?

Carbon isotopes are taken up through the diet of animals during their lifetime and these isotopes are deposited into teeth and bones of humans when they are consumed and digested. By studying animal bones and examining the ¹²C and ¹³C isotope ratio, it is possible to determine whether the animals ate predominately ³C or ⁴C plants. Oxygen isotopes are constantly being taken up and deposited into the body through the water a population drinks. This process ends with the organism’s death, from this point on isotopes no longer accumulate in the body, but do undergo degradation. For best result the researcher would need to know the original levels, or estimation thereof, of isotopes in the organism at the time of its death.

By creating a map of these natural occurring isotopes in different environments, rivers and areas, it is possible to identify where in an area the population lived, sourced their water or where the livestock grazed, by comparing the levels of isotopes that were obtained from skeletal remains to the environmental map. This mapping can also help identify trade routes that once existed and can also identify the migration patterns of populations.

References:

Balme, J., Paterson, A. 2006. Archaeology in Practice: A Student Guide to Archaeological Analayses. Oxford, UK: Blackwell Publishing. Pg 218.

Renfrew, C., Bahn, P. 1991. Archaeology: Theories, Methods and Practice. London, UK: Thames & Hudson. Pg 249-53.

If you’re new to the realm of archaeological, anthropological and forensic sciences (AAFS), or are a student needing sturdy and reliable references, or wondering “what archaeology or anthropology textbooks to buy?” Check out our new ‘Useful Literature’ page!

30/06/2015 by All Things AAFS!

Unusual-ology: Wasn’t Curiosity That Killed The Baboon… – Ancient Egyptian Pet Cemetery Found.

A team of archaeologists in Hierakonpolis have unearthed an ancient Egyptian animal cemetery, which has uncovered the remains of numerous exotic animals. The skeletal remains of numerous baboons, hippos, and other animals, have depicted a dark past for these companions of the ancient Egyptian elite.

The skeletal remains of the pets, thought to have been buried more than five thousand years ago, revealed numerous broken bones and fractures, which points to them having received harsh beatings. At least two of the baboon skeletons that were discovered had parry fractures, a common fracture of the ulna, caused when a victim is trying to shield their heads from damaging bones.

$The skeletal remains of the pets, thought to have been buried more than five thousand years ago, revealed numerous broken bones and fractures, which points to them having received harsh beatings. ©Renee Friedman$

The skeletal remains of a hippo calf showed evidence of a broken leg, which is thought to have been caused from the animal trying to free itself from a tether. This isn’t the only tether related injury that was discovered at the site; an antelope and a cow also showed similar injuries. The excavations at the Hierakonpolis site also revealed the remains of two elephants, two crocodiles, a leopard, and nine other exotic species. It is thought that the burial ground near to the Nile is the only archaeological evidence of such a wide assortment of zoo animals within ancient Egypt.

Wim Van Neer, a zooarchaeologist from the Royal Belgian Institute of Natural Sciences, noted that the ancient zookeepers “clearly had difficulty maintaining these animals”. The analysis of the skeletal remains showed that “the practical means of keeping animals in captivity were not so sophisticated as nowadays,” which would account for the numerous injuries sustained by the animals. The animals’ injuries showed signs of healing, which suggests that they were kept in captivity for a further several weeks or longer, rather than being killed immediately after obtaining them.

It is thought that the burial ground near to the Nile is the only archaeological evidence of such a wide assortment of zoo animals within ancient Egypt. ©Renee Friedman

It is argued by Richard Redding, an archaeologist of the University of Michigan’s Kelsey Museum, that the animals’ struggle whilst being captured could have led to the injuries. Van Neer agrees that some of the injuries could have been caused by the struggle, but the forty-plus broken hand and feet bones observed on the baboon remains are just “too numerous to be due to capture”. Van Neer also pointed out that an escaping baboon would have been more likely to break the long bones rather than the metatarsals and metacarpals, whilst escaping the capturers. It is also stated that the baboon remains from more recent tombs display fewer signs of harsh treatment, which may be due to the ancient zookeepers developing better animal keeping techniques.

References:

Van Neer, W. 2015. International Journal of Osteoarchaeology, 25:3. Pg 253-374.

25/01/2015 by All Things AAFS!

3-Million Year Old Fossilised Metacarpals Show Evidence of Tool Use.

A recent study has put forward some important evidence of early human ancestors, in particular Australopithecus africanus, wielding tools in a human like fashion dating around 3 to 2-million years ago.

Figure 1: A recent study has put forward some important evidence of early human ancestors, in particular Australopithecus africanus (pictured), wielding tools in a human like fashion dating around 3 to 2-million years ago . ©Shaen Adey, Gallo Images/Corbis.

The study, led by Matthew Skinner from the University of Kent, compared the internal structures of the hand bones from the Australopithecus africanus and several Pleistocene hominins, which were previously considered to have not engaged in habitual tool use.

Skinner et al, found that they all have a human trabecular (spongy) bone pattern in the metacarpals, and this is consistent with the “forceful opposition of the thumb and fingers typically adopted during tool use”.

Top row: First metacarpals of the various hominins. Bottom row: 3-D renderings from the micro-CT scans showing a cross-section of the bone structure inside.

Figure 2: Top row: First metacarpals of the various hominids.
Bottom row: 3-D renderings from the micro-CT scans showing a cross-section of the bone structure inside. ©T.L. Kivell

The evolution of the hand, mainly the development of opposable thumbs, has been hailed as the key to success for early humans. It is thought that without the improvement of our grip and hand posture, tool technology could not have emerged and developed as well as it has.

This piece of research will provide a new discussion into when the first appearance of habitual tool use occurred in prehistory, as this study’s evidence of modern human-like tool use is dated 0.5-million years earlier than the first archaeological evidence of stone tools.

References:

Skinner, M. Stephens, N. Tsegai, Z. Foote, A. Nguyen, N. Gross, T. Pahr, D. Hublin, J. Kivell, T. 2015. Human-like hand use in Australopithecus africanus. Science. 347, 6220. p395-399.
You can view this paper by clicking here.

If you’re a student – check out our ‘Quick Tips’ posts where we breakdown topics of AAFS into bite-sized chunks. We’re currently covering how to age and how to estimate the biological sex of skeletal remains, and also how to identify a variety of fracture types!

16/01/2015 by All Things AAFS!

Quick Tips – Common Questions: What can an anthropologist tell from the examination of teeth regarding either forensic identification of individuals or understanding past populations?

This is a Quick Tips post providing a basic answer to a commonly asked question often faced within the field of archaeology and anthropology.

An anthropologist can obtain a wide and varied collection of information from examining teeth. Information such as paleodiets and palaeoenvironments can be learnt from studying a population, or from studying an individual sample you can identify how old the person was at time of death or whether that person was pregnant/ill. These examples are just the tip of the iceberg on what you can learn from dentition.

An anthropologist can obtain a wide and varied collection of information from examining teeth, ranging from palaeodiets and palaeoenvironmental information to age of death.

From studying a large population dentition sample, a picture can be painted of their past diets, current diets and palaeoenvironments. Isotopes play a huge part in conducting research into palaeodiets and palaeoenvironments.

Isotopes are deposited into the teeth of an individual/population from food sources or environment. A tooth can provide isotopic information from the past 20yrs of the individual’s life. The enamel and dentine can be examined to analyse the isotopic values that will pinpoint an origin of a population or food sources. The carbon and nitrogen isotope compositions found within the enamel are used to reconstruct diet and the oxygen isotopes are used to determine the geographic origin of the food source. The carbon isotopes are absorbed from the diet of the animals that are sources and the oxygen isotopes from the water that the population consume. These isotopic values are vital in helping an anthropologist understand the local ecosystem a population exploited and whether a population migrated to numerous locations which caused changes in the available diet.

The cementum of a tooth can highlight important information about a person which can be used for forensic identification; this information could give an approximate age of death. An example of this application is seen in Kagerer and Grupe (2000) study where they obtained 80 freshly extracted teeth and investigated the incremental lines in acellular extrinsic fibre cementum. From studying the cementum, they were able to determine the age of the patient by comparing it to detailed queries of the patients life history. This study also identified patients who were pregnant. Kagerer and Grupe (2000) concluded that if there was a presence of hypo-mineralised incremental lines on the extracted tooth, the patient was pregnant. This is due to the pregnancies influence on calcium metabolism. A confliction with this is that hypo-mineralized lines can also appear when a skeletal trauma or renal illness was present.

By looking at the dentition of molars the age of the skeleton can be estimated. A recent study by Mesotten, et al. (2002) highlighted the application of forensic odontology. Mesotten, et al’s methodology consisted of examining 1175 orthopantomograms which belonged to patients who were of Caucasian origin and were aged between 16 and 22years. From their investigation Mesotten, et al. were able to conclude that from studying the molars, it was possible to age Caucasian individuals with a regression formula with a standard deviation of 1.52 or 1.56 years for males and females, respectively, if all four third molars were available. This could play a fundamental role in identifying a missing person by estimating the decease’s age and seeing if its estimate matches the individual.

Although the studies from Mesotten, et al (2002) and Kagerer and Grupe (2000) have been written about and applied to individual cases, their methodology and conclusions can be applied to a past population if a group of skeletons were found with preserved teeth. The individual’s age of death can be used as quantitative data, alongside other individuals from the same sample, to figure out a past population’s life expectancy.

References:

Kagerer, P. Grupe, G. 2000. Age-at-death diagnosis and determination of life-history parameters by incremental lines in human dental cementum as an identification aid. Forensic Science International. 118, 1. 75-82.

Mesotten, K. Gunst, K. Carbonez, A. Willems, G. 2002. Dental age estimation and third molars: a preliminary study. Forensic Science International. Volume 129, Issue 2, 110-115

To learn how archaeologists and anthropologists use teeth to age skeletal remains, read our Quick Tips: How To Estimate The Chronological Age of a Human Skeleton – Using Dentition to Age Subadults. Or to read more of our interesting Quick Tips, click here.

11/01/2015 by All Things AAFS!

Nine-ton Block of Sandstone Unveils Six Utahraptor Remains.

Archaeologists in Moab, Utah, have discovered the remains of six Utahraptors within a nine-ton block of sandstone. This discovery is regarded as the biggest fossil find ever of the Utahraptor, a giant predatory theropod dinosaur who roamed the earth during the early Cretaceous period. The massive excavation, led by Utah state palaeontologist James Kirkland, has been undertaken over the past decade upon the Utah Mountain.

The nine-ton sandstone block revealed the skeletal remains of a 16ft-long adult, four juveniles and a baby Utahraptor which was approximately 3ft long from snout to tail.

The sandstone block revealed the skeletal remains of a 16ft-long adult, four juveniles and a baby Utahraptor which was approximately 3ft long from snout to tail. The block also revealed bones belonging to a beaked, bipedal herbivore known as an Iguanadon. It is hoped that the Utahraptors died whilst hunting as a group, which may provide evidence of pack hunting. Another hypothesis claims that the Utahraptors may have wandered into quicksand and died at different times, due to the fossils being stacked 3ft thick.

It is hoped that the Utahraptors died whilst hunting as a group, which may provide evidence of pack hunting.

Kirkland thinks that the Utahraptors were enticed by the promise of the unwary Iguanodon which stumbled into the quicksand itself. Unable to move, bellowing and struggling, the trapped Iguanodon lured the Utahraptors who then, one after another, tried to ‘nab an easy meal’ only ending up stuck and meeting the same fate as the Iguanodon.

Utahraptors are the largest known member of the family Dromaeosauridae, with some specimens reaching 23ft-long weighing around 500kg. They bare a resemblance to their ‘cousins’ – the Velociraptor but are covered in feathers, with a sickle like claw on each of their second toes.

Size comparison of an average sized adult Utahraptor with an adult male human (5.9ft).

02/02/2014 by All Things AAFS!

Textbook of the Week: Archaeology in Practice.

Every week we highlight one archaeology/anthropology textbook from our suggested readings, a full list of our suggested resources can be found here, on our Useful Literature page.

Archaeology in Practice: A Student Guide to Archaeological Analyses (UK/Europe Link)

Archaeology in Practice: A Student Guide to Archaeological Analyses (US/Worldwide Link)

by Jane Balme and Alistair Paterson. Rating: ****

“This is THE book for how to apply archaeological methods in real life contexts. It is easy to follow, so perfect for first year students as it uses numerous case studies and illustrations to show you how to apply it in practice. I used this during my studies to wrap my head around how methods can be applied – which helped when methods were only briefly discussed in theory during my lectures.”

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24/01/2014 by All Things AAFS!

Textbook of the Week: Archaeology of Disease.

Every week we highlight one archaeology/anthropology textbook from our suggested readings, a full list of our suggested resources can be found here, on our Useful Literature page.

The Archaeology of Disease (UK/Europe)

The Archaeology of Disease (US/Worldwide Link)
(Click the links to have a peek inside the book)

by Charlotte Roberts and Keith Manchester. Rating: *****

“This is a essential if you’re studying diseases or taphonomy. It is fully illustrated with amazing case studies to display all diseases – ranging from simple fractures to malnutrition and infections.
Brilliant book, helped me a lot with my university Anthropology unit where I had to examine a bone and conclude which illness it had.”

17/01/2014 by All Things AAFS!

Textbook of the Week: Archaeology: Theories, Methods & Practice.

Every week we highlight one archaeology/anthropology textbook from our suggested readings, a full list of our suggested resources can be found here, on our Useful Literature page.

Archaeology: Theories, Methods and Practice (UK/Europe Link)

Archaeology Essentials: Theories, Methods, and Practice (Second Edition) (US/Worldwide Link)

by Colin Renfrew and Paul Bahn. Rating: *****

“This book is highly acclaimed and is the ultimate archaeology bible for students, or people new to archaeology and want to get stuck right in. After being recommended it by two of my University lecturers, I took it out from the library to use for my assignments so many times I ended up buying it.”

23/11/2013 by All Things AAFS!

Quick Tips: Use of Phytoliths in Archaeology.

Phytoliths are a very important identification tool in identifying plants within ancient environments, often even classifying down to the species of the plant.

But firstly, what are phytoliths? As the name phytolith suggests, coming from the Greek phyto- meaning plants and lith– meaning stone, they are tiny (less than 50µm) siliceous particles which plants produce. These phytoliths are commonly found within sediments, and can last hundreds of years as they are made of inorganic substances that do not decay when the other organic parts of the plant decay. Phytoliths can also be extracted from residue left on many different artefacts such as teeth (within the dental calculus), tools (such as rocks, worked lithics, scrapers, flakes, etc.) and pottery.

Table 1 & 2: Examples of the descriptors found within the International Code for Phytolith Nomenclature (ICPN), 2005, for use of naming phytoliths.
Figure 1: A bulliform phytolith under a microscope, ©Henri-Georges Nation.

Phytoliths can form numerous striking shapes within the plant cells (figure 1), which gives them a characteristic shape, thus aiding the identification of plants. Due to the vast number of shapes and sizes that phytoliths can come in, researchers compiled the International Code for Phytolith Nomenclature (ICPN), 2005. The ICPN was developed to create a standard protocol which is to be used during the process of naming and describing a new or known phytolith type, as well as a glossary of descriptors to help aid with the naming.

To observe phytoliths, a sediment sample needs to be collected preferably away from any human settlements, as the use of agriculture may have introduced non-native plants to the area. The soil sample is then observed under microscope or even scanning electron microscope (SEM). On the discovery of a phytolith after observation it needs to be named using a maximum of three descriptors, the ICPN (2005) can be used to correctly identify what descriptors should be used.

The first descriptor should be of the shape, either using 3D or 2D descriptor (whichever is more indicative/shows the phytoliths symmetry). The orientation of the phytolith should also be noted. The second descriptor should describe the texture and/or ornamentation, if characteristic or diagnostic and not an artefact of weathering.
The third descriptor should be the anatomical origin, but only when this information is clear and beyond doubt (Madella et al, 2005).

Phytoliths are very important and useful if the sediment they are taken from is hostile to the preservation of fossil pollen, so may be the only evidence available for paleoenvironment or vegetation change.

References:

Balme, J., Paterson, A. 2006. Archaeology in Practice: A Student Guide to Archaeological Analayses. Oxford, UK: Blackwell Publishing. Pg 218.

Madella, M., Alexandre, A., Ball, T. 2005. International Code for Phytolith Nomenclature 1.0. Annals of Botany, 96: 253-260. A .pdf of this paper available here.

Renfrew, C., Bahn, P. 1991. Archaeology: Theories, Methods and Practice. London, UK: Thames & Hudson. Pg 249-53.

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