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.

Stone Circle at Drombeg

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

Isotopes Table

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!

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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 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 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.

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!

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 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.

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).

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

200-Million-Year-Old Ichthyosaur Complete Fossil Discovered.

An ichthyosaur fossil, dating back to around 200 million years, has been discovered on a beach in Penarth, South Wales.

The 7ft fossil, weighing in at 132lbs, was unearthed on a beach in Penarth, South Wales.

The 7ft fossil, weighing in at 132lbs, was unearthed on a beach in Penarth, South Wales.

The 7ft fossil, weighing in at 132lbs, was unearthed by beach walker Jonathan Bow, who spent a whole day excavating it. Cindy Howells, a palaeontologist from the National Museum of Wales said: ‘The ichthyosaur is potentially a very, very important find because it is so complete.’

Ichthyosaur Fossil 3

Ichthyosaur Fossil 2-Head

Ichthyosaurs are commonly referred to as fish lizards, but are in fact large carnivorous marine reptiles varying from 3ft to 52ft in length. They thrived during the Mesozoic era, and are thought to have made their first appearance around 250 million years ago.

It is thought that the ichthyosaur population increased during the later Triassic and early Jurassic Period, but then became replaced by the plesiosaurs during the later Jurassic and Cretaceous Period. By the Late Cretaceous period, ichthyosaurs became extinct.

Ichthyosaurs are commonly referred to as fish lizards, but are in fact large carnivorous marine that thrived during the Mesozoic era.

Ichthyosaurs are commonly referred to as fish lizards, but are in fact large carnivorous marine that thrived during the Mesozoic era.

Unique Aztec Dog Burial Discovered.

Archaeologists from the National Institute of Anthropology and History (INAH) have uncovered twelve dog skeletons whilst excavating in the Aztec capital of Tenochtitlan. Dog burials are a common practice within archaeology, but what stands this particular discovery out from the crowd is that there is no human burial, or even building associated to this burial.

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One of the well-preserved dog skeletons found.

The reason why dogs were often found alongside human burials is linked back to the animal’s symbolism in Aztec mythology. It was believed that even after death, dogs still served their masters. The belief was that the dogs helped guide the owner’s soul through the hazardous underworld until they safely reached Mictlan, the resting place of the dead.

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The placement of the dog skeleton’s have no pattern, leaving archaeologists wondering what is the significance behind this burial.

The dog’s skeletal remains have been date back to 500 years, and they were well-preserved and most were complete and articulated . Their placement within the burial ground has no discernible pattern to it, leaving the archaeologists wondering what the significance of this burial is, although archaeologists have deduced from the skeleton’s measurements that the dogs are likely to be common breeds as their stature are much taller than the native Mexican breed of Techichi.

Unusual-ology: ‘Rare’ Prehistoric Spider Fossil Found.

A fossil of a large male prehistoric spider has been recently found in the Daohugou beds of Inner Mongolia.  The spider’s species has stumped scientists, who have now proposed a new genus for the discovery called Mongolarachne.

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The male prehistoric spider fossil that was found in the Daohugou beds of Inner Mongolia.

This recent discovery comes after the previous unearthing of a female spider fossil in the same area back in 2011. The 165-million-year- old female spider is thought to have belonged to the Nephila species due to its size being close to the modern day Nephilidae (orb-weaver spiders), and was so called Nephila jurassica. But this newly discovered male spider fossil throws a spanner in the works.

While the male spider does resembles the Nephila jurassica, its shape and size has suggested it belonged to another genus. One factor that called for a new genus was its sex appendages, as they did not match those found on modern day Nephila males. Also the male has ‘spirals of hairlets’ that are more feathery than those on modern day orb-weavers.

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While the male spider (left) does resembles the Nephila jurassica (right), its shape and size has suggested it belonged to another genus.

These differences have led to Professor Paul Selden from Kansas University, who was part of the teams that discovered both fossils, and other scientists to propose the new genus Mongolarachne from the family Mongolarachnidae. According to Selden’s (2013) paper, these Mongolarachne closely resemble the modern day ogre-faced spiders that belong to the Deinopidae family.

Spider fossils are considered rare because of the soft composure of their bodies, but these two fossils were found within volcanic deposits. It is believed these deposits buried this pair at the bottom of a lake, therefore preserving them in very good condition.

References:

Selden, P.A., Shih, C., Ren, D. 2013. A giant spider from the Jurassic of China reveals greater diversity of the orbicularian stem group. Naturwissenschaften, 100:12. Pg 1171-1181.

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!

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Well Preserved Dinosaur Tail Found in Mexico.

A team of archaeologists and students from of the country’s National Institute for Anthropology and History (INAH) have found a remarkably well preserved fossilised remains of a suspected dinosaur tail, near the town of General Cepeda, Coahuila in northern Mexico. The director of the INAH, Francisco Aquilar, has said that the tail, which has been measured to be five yards long, is the first one of its kind to be found in Mexico. The tail was identified to be belonging to a hadrosaurid ( a duck-billed dinosaur), where it is likely representative of  half the dinosaurs full length.

Top: The fossilised tail remains of the hadrosaur, recently discovered in northern Mexico.  Bottom: A electronic  artist rendering of the appearance of the suspected dinosaur.

Top: The fossilised tail remains of the hadrosaur, recently discovered in northern Mexico.
Bottom: A electronic artist rendering of the appearance of the suspected dinosaur.

But this tail hasn’t been the only fossilised remains of dinosaurs that they have found on this archaeological site. The archaeologists have also found what is suspected to be one of the dinosaurs hips. There have also been numerous dinosaur remains found within the state of Coahuila, with Aguilar noting that they have “a very rich history of paleontology” within that area.

There was an earlier fossilised remains discovery in 2010. The fossilised remains were of a never before discovered dinosaur within the same northern Mexico state as the recently discovered tail. The remains of the Coahuilaceratops, which was aptly named after the place of discovery, was discovered by a research group of palaeontologists from the Utah Museum of Natural History at the University of Utah. The excavation of the Coahuilaceratop marked the unearthing of the first horned dinosaur ever to be discovered in Mexico (News Center, 2010).

References:

Daily Mail. 2013. What happened to the rest of it? Archaeologists discover a 72million-year-old dinosaur tail in Mexican desert. Daily Mail News Online. Click here for an article about the dinosaur tail.

News Center. 2010. First Horned Dinosaur from Mexico. University of Utah. Available here. 

Unusual-ology is a new post type which focuses on weird new articles/science areas that have cropped up and caught my eye.

To read the Unusual-ology post on the Ancient Egyptian use of lettuce as an aphrodisiac, click here, or how male spiders sacrifice themselves to their mate, click here. Looking for an interesting article on the recent vampire burials, and past vampire burials, clickety click here.