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Ancient Water, Deep Life

18 Dec

I haven’t posted here as much as I have wanted to recently due to a combination of factors.  Firstly my laptop broke, secondly I’ve been busy at work now that the arm has healed up (x-rays of the fracture here), and thirdly I’ve also been conducting an osteoarchaeological side project.  (I’m also expertly, somewhat even academically, ignoring a slew of deadlines which are fast approaching for a few writing projects).  However this is just a quick post to say that there should be a few posts over the next month or so.  A few of these posts have been drafted earlier in the year and are half-finished, but it is hoped they’ll be finished shortly.

In the meantime, and in non-osteo news, I couldn’t help but notice two particularly interesting science articles on the BBC news website earlier today.  Both news articles are probably not new to geologists, oceanographers or geophysicists, but they have certainly piqued my interest.  There is evidence that biological life, in the form of microbes, have been found living at a depth of 2400m beneath the seabed off the coast of Japan.  Although the organisms are single-celled they do seem to manage to survive on a diet of hydrocarbon compounds whilst only expending low amounts of energy.  The microbes have been found in coring samples from an ancient coal bed system, which was drilled by the International Ocean Discovery program in 2012 in the Shimokita Peninsula, Japan.  Amazingly the drill was sent down through 1000m of seawater and through 2446m of rock under the seabed itself.  At such depths there is little water, limited nutrients, no light and no oxygen, yet life still survives.  Tantalizingly research still remains to be conducted on how the microbes came to be at this location and at this great depth.  Read the article here on the BBC.

The other science news article deals with water of a different order.  The world’s oldest deep water is present in a much greater volume than previously estimated.  Located within the Earth’s crust, where some of the oldest rock can also be found, ancient water has been sampled through boreholes and mines and the revised estimate of the volume suggests there is around 11 million cubic kilometres present in the crust.  The world’s oldest dated water has been located in present day Canada in a mine located 2.4km down into the crust, estimates put the water at around 1 billion to 2.5 billion years old (yup billion!).  The fact that the water is so old, and preserved so well, has surprised many and also revises the estimates of hydrogen produced on earth.  Previously it was thought that continental crust produced almost zero hydrogen compared to ocean crusts.  Again, the full article can be found here on the BBC (1).

Both news articles are the result of research coming from the currently ongoing 47th American Geophysical Union Fall Meeting in San Francisco (15th-19th December with a whooping 24,000 delegates!), which covers Earth and space science topics.  I’ll certainly be keeping an eye out for further news as this is incredibly interesting as scientific research continues to extend our knowledge of where, and how, life not only survives but seemingly thrives.

Notes

(1).  The scientific literature has not been referenced in this post but I will update once this becomes either available and/or when I have the time.

19/12/15 Update

In other extreme life news the New Scientist magazine has reported the filming of a fish (a possible snailfish) at the depth of 8143m below the surface at the Marianas Trench, in the Pacific Ocean.  The Marianas Trench is the deepest part of the world’s oceans, and the filmed footage of the snailfish at this extreme depth highlights once again how life can survive in hostile environments.  The intense pressure at this depth places severe limitations on the function of muscle and nerve tissues, however snailfish are known to survive in such intense pressure environments with another species, Pseudoliparis amblystomopsis, having been studied and recorded at depths of 7703m before.

Diggin’ Dinos: Jurassic World

26 Nov

First things first I’m a realist – archaeologists (and bioarchaeologists) do not dig dinosaur bones, that job alone is for palaeontologists.  Palaeontology is the study of life largely prior to the Holocene period, and largely the study of fossils within a geologic context, which mixes the boundaries of geology and biology to inform on the evolution and variety of life.  The study of dinosauria, or dinosaurs as they are largely commonly known as, who became the dominant land clade throughout most of the Triassic to Cretaceous periods (within the Mesozoic geologic era), is but one part of this.

But I would be lying if I did not state that my interest in bones started early and, specifically, that it started with the dinosaurs.  More specifically still it started with Jurassic Park, a film released in 1993 by one Steven Spielberg that saw my 5-year-old self keenly watching in the local cinema.  I was fascinated by the creatures on the screen, these primordial beasts tearing to shreds the Homo sapiens who thought they could control what they had resurrected.  I was intrigued by their form, the variations in the anatomy and the differences in the (admittedly on-screen) behaviour.  Here was a film that didn’t just make the audience scared and excited, it also gave the creatures a semblance of intelligence.  Who were these long extinct creatures?  What was Dr Grant doing in the desert scaring kids with a raptor claw, whilst also overseeing someone shooting shotgun shells into the earth?  Wait, is that is a job? I thought to myself.

I was hooked.  I want to dig in the desert!  That looks great I thought.  Those creatures looks awesome!  Clearly I had to learn more.  Safe to say that the following Christmas was taken up with Jurassic Park toys – the triceratops that had a gouged bit of flesh that could come off, and the helicopter that, if I remember correctly, barely appeared in the film.  But I wanted to learn more than just play with the toys and watch the film again and again (could those raptors really open doors!).  I wanted to learn about the creatures that the film was based on, I wanted to know more about their life contexts, their habitats and their geographic span.  Just when did they live and how did they come to die out?  In a word I was curious, and I remain curious to this day about the natural world around me.

It started out with the toys, dinosaur Top Trump cards and other bits and bobs.  I collected the glow in the dark model skeletons that always seemed to flash up on the television, bit by bit I pieced together a Tyrannosaurus rex skeleton that looked somewhat badly proportioned.  My father subscribed me to a dedicated dinosaur magazine that explored the fossil remains a bit more in-depth, and I collected a few cast fossils of various parts of various creatures from the past.  At the major museums I would clamour around the cases that showed the fossils of dinosaurs and more recent mammals, always thinking about what these creatures must have seen during their own lifetimes, how very different our two worlds were.  In time Jurassic Park: The Lost World was released and I became enraptured all over again.  An early precursor to this blog was created during my primary school days where I put together a mini-book of drawings of Protoceratops, Triceratops, Brachiosaurus, Iguanodon, Ankylosaurus and co. with information boxes supplying the basic data of when and where they lived and what they ate.  I was thrilled when Baryonyx was found and described, a highly specialised fish eater in southern England of all places (though of course plate tectonics have substantially moved the earth’s surface around since the Late Cretaceous days).

I hate to say but this lust for dinosaur knowledge faded somewhat during my late primary school years where I was given to drawing what I thought the inside of my leg may have looked like with the-then new temporary titanium plate that was holding my left femur together (that very plate now rests in one of my draws!).  It was a natural progression from the distant past into an immediate and visceral present, one that gripped me as I learnt that bone is living, changing and dynamic material that responds to the pressures that we place it through.  But still the love for dinosauria flares up from time to time, perhaps no more so than when the BBC released the Walking with Dinosaurs television show in 1999, a real marker in the sand for the intelligent presentation and discussion of the biology and life experience of dinosaurs.  After each episode aired I would spend the next day at school talking with my friends about the episode, excitedly huddled around before the drudgery of school started.  But I did not go on to study palaeontology at any point, although I still maintain a relative interest in the latest discoveries and theories on the biology of dinosaurs and ancient life.

For me there is a certain inherent sadness when looking at the remains of species that have fossilised and have been described and documented.  The question of what lifeforms are we missing from deep geological time periods that did not survive the taphonomic processes, and luck of the draw that has preserved so many skeletons as fossils, often abounds in my head when I view specimens and casts displayed in natural history museums or spread across the pages of books.  In a way, by studying the skeletons of the more recent human past, it perhaps negates in some small way the limited archaeological remains that may, in time, become fossils themselves.  Arguably, of course, we may be destroying that record ourselves.

So no I am not a palaeontologist and I do not dig or study dinosaurs, I am a human osteologist who studies the skeletal remains of humans from archaeological contexts.  It was a close contest, but in the end I adapted to a subject that was close to my heart, that gave me a tangible connection to the past human population instead of the past animal population.  It is a distinction, but it is worth bearing in mind that the Homo sapiens species are just natural animals as well, even though life itself is a wonder.

But let me post what the blog title promises.  My interest has been piqued and, finally, the 3rd much talked about sequel is happening.  (I almost conveniently forgot about the 3rd film whilst writing this, although Spinosaurus still rocks).  Here is the just released trailer for the new 2015 movie Jurassic World*:

* I’m crossing my fingers that this is a beast of a film…

Further Information

  • Check out the palaeontologist Jon Tennant’s fantastic and informative blog Green Tea and Velociraptors for some of the latest updates in palaeontology.
  • Take a read of Neil Shubin’s fascinating book Your Inner Fish: A Journey into a 3.5 Billion year History of the Human Body.  I managed to get a copy a few years ago and it is an invigorating read on the hardships of palaeontological fieldwork that also gives an interesting account of the lab work that goes hand in hand with field explorations.  More importantly this book highlights the evolution of the human body via various parts of both extinct and extant life forms.
  • With fantastic timing a new paper by Hone et al. (2014) discusses a case study of a mass mortality event of juvenile Proterceratops discovered in Mongolia and size-segregated aggregated behaviour in this specimen of dinosaur.  There is the suggestion of sociality but the authors are rightly conservative in their observations.  There is an intriguing remark on the estimation on the age of ceratopisan dinosaurs – “Furthermore, at least some non-avian dinosaurs apparently reached sexual maturity long before reaching terminal body size or somatic maturity [36][38]. The result is a quagmire of varying definitions for ontogenetic stages and ontogenetic assignments across different publications even for single specimens” (Hone et al. 2014).  The taphonomic interpretations of this mass mortality sample is also particularly interesting and I’d recommend reading the accessible paper.

Bibliography

Hone, D. W. E., Farke, A. A., Watabe, M., Shigeru, S. & Tsogtbaatar. 2014. A New Mass Mortality of Juvenile Protoceratops and Size-Segregated Aggregation Behaviour in Juvenile Non-Avian Dinosaurs. PLoS. DOI: 10.1371/journal.pone.0113306. (Open Access).

Ungulates Gnawing: Osteophagia & Bone Modifications

24 Oct

Osteophagia: Osteophagia is the act of ungulates (including giraffes, camels, cattle, etc.) chewing on another species skeletal remains to gain nutrition (particularly minerals such as phosphorus and calcium) that may be lacking in other parts of their largely vegetarian diets.  This includes the chewing of antlers, horns and ivory, as well as skeletal elements.  It is a relatively well documented animal behaviour that occurs across numerous taxa and across continents.

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I’ve been meaning to highlight this article by Hutson et al. (2013) for a while as it nicely illustrates the actions of animals in the archaeological record that can sometimes be interpreted, or mistaken, for a human or taphonomic origin.  Hutson et al. (2013) discusses the impact that ostephagia can have on archaeological contexts and carefully identifies the differences between large and small ungulate osteophagia-based actions.  Taking 12 individual and observed case studies of osteophagia examples recovered from modern field contexts in Australia, North America and Africa, the study highlights the different styles of bone modifications made by each species to help identify the often distinct bone modifications that they leave in their wake.  The case studies include examples of wildebeest (C. taurinus) bones having been gnawed by giraffes, elephant (Loxodonta africana) ivory gnawed by kudu or sable antelope, and a camel (C. dromedarius) radius fragment having been gnawed by a camel.

Hutson et al. (2013: 4140) notes that ‘previous studies have shown that ungulates gnaw both cortical and cancellous bone and elements in almost any state, from fresh to completely bleached, desiccated, and weathered”.  The favoured bones to gnaw during scavenging among ungulates are elements of the long bones, vertebrae, scapulae, skulls and ribs, and, if munching on long bones, the larger ungulates often position the axis of the bone ‘like a cigar held in a human mouth’ (Hutson 2013: 4140).

ostephagia 111 hutson etal13

This diagram shows porcupine gnawed B. taurus limb elements, where a) is the right tibia and b) is the left femur. Notice the what look like long striations, which are in fact gnawing lines (click to enlarge). Image credit: Fig 8 from Hutson et al. 2013: 4147.

Importantly, the authors differentiate the classes of ostephagia-based bone damage caused by large ungulates and compare it to the typical bone damage caused by carnivores and other primarily meat-eating scavengers, such as lions, panthers and tigers.  This comparative approach takes into account 10 separate features of bone damage often found on gnawed skeletal remains (including evidence of prey selection, bone selection, bone state, bone transport, tooth mark type and general morphology amongst others) and highlights the varied differences between the two behaviours of ungulates and carnivores (Hutson et al. 2013: 4148).  Perhaps of primary importance in this article is that fact that tooth morphology varies according to species and purpose, as such the authors explicitly highlight that, alongside this, the age of the individual animal, and thus the state of its teeth, gnawing the bone can affect the patterning expected (Hutson et al. 2013: 4147).

ostephagia hutson etal13

This rib was found at the fringe of a scatter of skeletal elements from one individual. Showing the distinctive forking and crushing of ungulate gnawing, this B. taurus rib was likely gnawed by cattle whilst still relatively fresh. Image credit: Fig 6. in Hutson et al. 2013: 4145.

Of course care should always be taken in the recording of gnawing evidence, as teeth in both humans and non-humans can wear down and gouging styles can vary.  However, the distinguishing marks made between ungulates during the act of osteophagia and the selectivity of active carnivores and scavengers is vital for the archaeologist as it can infer on the context of the gnawed skeletal remains.  This can help identify the fauna previously present on-site and the actions that took place based on replicating the known evidence.  The analysis of faunal bones at archaeological and palaeoanthropological sites should, of course, be used in conjunction with other taphonomy techniques to fully understand site formation.

All in all, this is an interesting paper that adds real depth to the taphonomic literature and should be of note to both archaeologists and palaeoanthropologists in interpreting the actions of both humans and non-humans during site formation.

Update 26/10/14

Osteophagia is just one method that mammals use to gain extra nutrients in their diet, another method is mineral lick.  As with osteophagia it has long been noted that animals will exploit their environments by eating or otherwise digesting natural soils, clays and rocks to gain elements (particularly salt) that may be missing in nutrient poor ecosystems (Lundquist & Varnedoe Jr 2006).  Mineral lick is particularly prevalent among giraffes, elephants, moose, cattle and tapirs (and other mammals) as a way to increase the amounts of minerals, such as potassium, calcium, sulfur, phosphorus, and sodium, in their diets.  Although the knowledge of so-called salt caves and their origin with animal behaviour is well know, it is thought that they are under-estimated in current estimates of their prevalence (Lundquist & Varnedoe Jr 2006: 18).  As such these natural landscape features should also be taken into account when understanding the formation and duration of palaeoanthropological and archaeological sites.

Bibliography

Hutson, J. M., Burke, C. C. & Haynes, G. 2013. Osteophagia and Bone Modifications by Giraffe and Other Large Ungulates. Journal of Archaeological Science. 40 (12): 4139-4149.

Lundquist, C. A. & Varnedoe Jr, W. W. 2006. Salt Ingestion Caves. International Journal of Speleology. 35 (1): 13-18. (Open Access).

Killer Whales: A BBC Natural World Documentary

26 Oct

The BBC strand of a wildlife documentary series, entitled Natural World, have a new episode up on the BBC Iplayer focusing on recent scientific research on the globally distributed killer whale (Orcinus orca).  It is available to view here, although readers outside of the UK may have trouble watching it online (If you have any links please leave a comment!).

It was whilst watching the program, and its discussion on whether there are different species of killer whale (likely 3-5, with various sub-species), that it reminded of the Dmanisi Homo erectus fossils (Lordkipanidze et al. 2013) which were subject of the previous post.  Lordkipanidze et al. (2013: 330) postulated that the morphology of the 5 Homo erectus crania present at Dmanisi, Georgia, represent, when examined against comparable material, the evidence for wide morphological differences within and among early Homo, possibly indicating rather less individual species than is currently documented and described.

The Natural World episode highlighted the differences between killer whale ‘cultural’ groups and species with niché but distinct differences in external anatomy (body size, eye and saddle markings, shape and size of dorsal fins), vocalisation and the different hunting methods used when groups targeted varying prey groups.  This is important as it will help to inform on how humans try to conserve killer whale populations around the globe as an understanding of the distinct species could have an important ecological impact on what groups of killer whales are under threat the most.  Of course the big difference between the above comparison was the use of DNA testing and active observational fieldwork, if only we could test the early Homo fossils in such a way!

Further into the program we came across evidence of an individual killer whale who had likely been maimed as a juvenile and who had been adopted, at different times, by no less than 4 different pods of killer whales. There was also footage of said killer whale shadowing and receiving food from one member of her current pod who could successfully hunt (whether this was deliberate is another question).  This reminded me of a nice little paper by Fashing & Nguyen (2011) of the relevance of behaviour towards disabled, injured or dying individuals among animal groups and it’s relevance towards palaeopathology.

Palaeoanthropologists should take into account the wider aspect of how animals treat members of their own species when they are disabled, injured or dying, as Fashing & Nguyen (2011: 129) note that ‘recent evidence from paleoanthropology indicates that inferences into the evolution of human behavior based solely on a chimpanzee model are less informative than previously believed’.  Lordkipanidze et al. (2013), in their study, compare the Dmanisi individuals against modern Homo sapiens and chimpanzees, amongst others, but it could be said that these two groups in particular do not reflect good study comparative groups as their anatomical plasticity is generally quite homogeneous.  As ever, of course, further research is needed and I for one look forward to it.

The program also debated the troubling nature of the capture of killer whales for the purposes of entertainment for large sea life centers across the world, a practice that has now been largely banned in the Western World.  There is a haunting passage in the Natural World episode showing archive footage of the frenzy of killer whale captures during the 60’s and 70’s, with an appropriately sinister (and awesome) Pink Floyd track playing in the background.  Killer whales are, by their nature, large social predators – they need the security of their family pods and the sea environment in which to live and to hunt.

At SeaWorld, in the United States of America, there have been a recorded 100 separate episodes of aggression towards humans from captive killer whales since 1988, and there have been 4 recorded fatalities of trainers involving captive killer whales across the globe.  Let me re-iterate here that killer whales pose little threat to humans in the wild, that there has been no recorded human death by killer whale in the wild but there have been incidents (see list).  Clearly captivity leads to abnormal behaviour amongst these amazing creatures, as it can be said for many animal species (worth a watch is the 2013 documentary Blackfish).

All in all, this was an enlightening program on the advances made in studying the killer whale, highlighting the distinct hunting differences, group structure and vocalisation of an apex predator who has both inspired and caused fear in humanity throughout the ages.  It is well worth watching the episode, if not the series, for insights into the natural world.  Previous episodes worth a watch also deal with the remarkable walrus and the delightful orangutan.

Watch the BBC documentary here (United Kingdom residents only).

Bibliography

Fashing, P. J. & Nguyen. 2011. Behavior Towards the Dying, Diseased, or Disabled Among Animals and its Relevance to Paleopathology. International Journal of Paleopathology. 1 (2-3): 128-129.

Lordkipanidze, D., Ponce de León, M. S., Margvelashvili, A., Rak, Y., Rightmire, G. P., Vekua, A. and Zollikofer, C. P. E. 2013. A Complete Skull from Dmanisi, Georgia, and the Evolutionary Biology of Early HomoScience.  342 (6156): 326-331. (Full article here, email if this doesn’t work).