Here we go again. News headlines are proclaiming that a recent discovery of a fossil jawbone in Israel will ‘completely rewrite’ everything we knew about human evolution.
Well no. First of all this new find does not effect at all our understanding of human ancestral species such as Homo habilis or Homo erectus, nor related species such as H. neanderthalensis. Secondly, it is only the dating of the jawbone, which is yet to be confirmed by the way, which is a surprise to anyone. What this fossil is likely to do is push backward by some 50,000 years the date of the migration of our own species, H. sapiens out of Africa.
First a few facts. The fossil jawbone was discovered in the Misliya cave on the western slope of Mount Carmel in Israel, see images of the cave and jawbone below. The jawbone was found in association with stone tools of a type known as the Early Middle Paleolithic. Based upon the tool type and dating of the soil deposits in which the jawbone was found the fossil is considered to be between 177,000 and 194,000 years old.
That date makes this jawbone the earliest known fossil of H. sapiens outside of Africa by 60,000 to 80,000 years. This tremendous leap backward in time implies that our species had left Africa much earlier than anthropologists had previously thought. In fact until recently it was thought that H. sapiens had only evolved 200,000 to 250,000 years ago.
However in June of 2017 fossils of H. sapiens from the Jebel Irhoud site in Morocco were dated to around 315,000 years ago pushing back the origin of our species by almost 100,000 years. These finds correlate quite well with the new find in Israel and some researchers are already using this data to develop a new timeline of human evolution.
With all of these new finds paleontologists are bringing us ever closer to a clearer more detailed picture of the evolution of our species. One thing is certain, more fascinating discoveries are certain to be made.
Before I go I’d like to take a few minutes to talk about tomorrow’s Superbowl, number 52 in case you’re counting. I know what your thinking, sports isn’t science, what is the Superbowl doing here. Aren’t I really just doing this because my hometown team the Philadelphia Eagles have been the surprise of the NFL season by going from a losing record last year and making it all the way to the Superbowl this year. But please bear with me.
It’s true; nobody picked the Eagles to go very far this season. Their record last year was 7-9 and although they had some good young players all of the analysts agreed that they needed more experience before they’d go very far. Hey, even their coach was inexperienced, last season was his first year as a head coach anywhere.
From the first game of the season however the Eagles have played with a great deal of enthusiasm and in this town when the players try hard the Philly fans will support them like no other fans anywhere. Really the feedback between players and fans in this city is something to behold. So that’s the Eagles strength, youth, enthusiasm and a desire to show that they really are as good as their 16-2 record indicates.
Our opponents are the New England Patriots, making their eighth appearance at the Superbowl in the last seventeen years. Generally considered the strongest dynasty in football (American football that is) during the modern era the Patriots have all the experience you could ask for. In addition the Patriots have the calm, deliberate confidence that comes with repeated success, with knowing for certain just how good you are.
That’s what this year’s Superbowl is really about: experience versus enthusiasm, confidence versus desire. And if you think about it, isn’t that a big part of life in general, the differences are just usually not that clear cut most of the time.
I think that makes this Superbowl a bit more interesting than in most years, or is it just that my hometown Eagles are in it?
Two years after Charles Darwin published his book “On the Origin of Species” in 1859 a fossil was discovered at the Solnhofer Limestone quarry in Bavaria in Germany. Even today that fossil is considered one of the most important pieces of evidence for the theory of evolution. The fossil was that of a small animal, a lizard-like creature with a mouth full of teeth, a long bony tail and three fingered claws on each arm.
The animal also had feathers, hundreds of beautiful feathers preserved in such detail that there could be no doubt but that these were flight feathers. This was a flying reptile, a transition species between the reptiles and birds, just the sort of creature that Darwin had predicted. This was Archaeopteryx. The image below shows that first specimen of Archaeopteryx.
Other specimens of Archaeopteryx have been discovered in the century and a half since that first find, and paleontologists have also found other species that show combinations of bird and reptile characteristics. Now a 12th specimen of Archaeopteryx has been found at the original Solnhofer limestone pit. The specimen, discovered by researchers from The Ludwig Maximilians Universitaet in Munich is dated to the Jurassic period, 150 million years ago and is believed to be the oldest Archaeopteryx ever found.
Today paleontologists place Archaeopteryx near the theropod dinosaurs on the evolutionary tree making the early bird a close relative of the mighty T-rex. Indeed many modern evolutionary biologists advocate separating the dinosaurs entirely from the reptiles and classifying them with the birds instead. That would mean that there are still dinos alive today, one just flew past my window.
It is hoped that the new specimen will help to clarify the relationships between the theropods and the earliest birds. The image below shows the new specimen of Archaeopteryx.
Along with the specimens of Archaeopteryx the Solnhofer limestone quarry in Bavaria has provided science with many of the best-preserved and studied fossils from the Jurassic period. At that time the area we now call southern Germany was a series of tropical coral reefs and lagoons where the water was often cut off from the nearby Tethys Sea. The heat of the Sun caused rapid evaporation that increased salt levels and reduced oxygen levels to the point where microorganisms could not survive. Any living creature that wandered into, washed into or in the case of Archaeopteryx fell into these waters sank to the bottom and did not decay! Because of this fossils in the limestone are rare, but they are exquisite. The images that follow are example of some of the finds discovered there.
Another transition between two well-known groups from Solnhofer is shown in the image below. Officially classified as a crab the fossil obviously has a much larger tail than any crab you’ll find in the oceans today. Clearly this creature is a lobster caught in the act of evolving into a crab.
The limestone sheets from Solnhofer are of such fine grain and uniform consistency that they have been used to make lithographic prints since the Middle Ages. So fine are the deposits that even the wings of insects and soft-bodied animals like jellyfish are fully preserved.
Paleontologists call fossil sites like Solnhofer ‘Lagerstätten’ or mother loads because the fossils are so valuable in our efforts to understand the history of life on our planet. The Burgess shale in British Columbia is another famous Lagerstätten where soft bodied animals from near the beginning of multicellular life are amazingly preserved. Someday I’ll have to tell you all about that.
This month there have been several news items concerning discoveries about ancient life that I’d like to spend a little time discussing. The research spans the whole history of life here on earth from it’s very beginning to just before the start of recorded history. I think I’ll start at the beginning and work my way forward in time.
The first story is actually an update or perhaps I should say progress report on the work being done at The Scripps Research Institute (TSRI) into the chemical processes that literally came to life almost four billion years ago. In my post of 11Nov17 I described how a team of chemists led by Doctor Ramanarayanan Krishnamurthy at TSRI had discovered that a catalyst called diamidophosphate or DAP could have provided a means for the three basic chemical groups of life, nucleic acids, proteins and lipids to have come together into a single pre-living cellular structure.
Now Dr. Krishnamurthy and his team have gone further, focusing on the chemical reactions that provide energy for cells, the citric acid cycle. Modern living organisms use the citric acid cycle to release the energy stored in sugars and fats. However the chemical components necessary for the critic acid cycle probably did not exist on the early Earth.
What the scientists have now done is to show that two non-biological cycles, the HKG cycle and Malonate cycle could have worked together to accomplish the same metabolic function as the citric acid cycle. Then, as more efficient biological catalysts became available HKG and Malonate could have been replaced by citric acid while leaving the basic structure of the cycle in place. As Doctor Greg Springsteen of Furman University and a co-author of the study stated, “Modern metabolism has a precursor, a template, that was non-biological.” How the HKG/Malonate cycle would work is detailed in the image below.
Now I took two courses in organic chemistry as an undergraduate and I do remember learning a bit about the critic acid cycle but I freely admit some of this stuff is over my head. However, if you’d like to learn more about the research going on at the Scripps Institute click on the link below to be taken to their website.
The next article also deals with early life but a good deal more advanced than that which is being studied at TSRI. In fact the fossils in the study represent the earliest known multi-cellular creatures, organisms that also used photosynthesis and engaged in sexual reproduction. The fossils themselves were collected more than twenty years ago from Somerset and Baffin Islands in Canada but their dating had been in question from their first description. A range of possible dates stretched from 720 million to 1.2 billion years ago which could either make the fossils nothing special or much too advanced for anyone to believe.
The study by researchers at McGill University used new radio-chemical dating techniques to narrow the possible age of the fossils to between 1.03 and 1.06 billion years old, an age that excites paleontologists without giving them a heart attack. The image below shows some of the fossils, which have been given the name Bangiomorpha pubescens because it resembles the modern red algae bangio.
In the image the fossils obviously are multi-cellular and in the image at bottom right asexual spores can be seen. In other examples sexual spores have also been found making Bangiomorpha pubescens the earliest known example of a sexually reproducing species.
My final discovery is much more recent in age and deals with human migration into the Americas. Excavations at the Upward Sun River archaeological site in Alaska have unearthed the remains of an infant girl that have been dated to 11,500 years ago. Preserved by the cold the remains were in such good condition that a genetic analysis was possible. The DNA analysis revealed that the girl belonged to a previously unknown, ancient group of people. The image below shows some of the dig site.
“These are the oldest human remains ever found in Alaska,” says Professor Eske Willerslev of the Universities of Cambridge and Copenhagen. Prof. Willerslev adds that the girl came from “a population that is most closely related to modern Native Americans but is still distantly related to them. So, you can say that she comes from the earliest, or most original Native American group.”
Scientists hope that further studies of the remains along with all of the material finds at the Upward Sun River site will reveal more about how the Americas were first settled and by what kind of people.
We’re down to the last few days of the year 2017 and all of the news outlets are doing special reviews of the ‘Top Stories’ that they covered during the past year. With this in mind I’ve decided to use my final post of the year to review some of the stories I’ve written about in 2017.
First of all let’s look at some of the numbers. Over the past 52 weeks I’ve now published 102 posts so it hasn’t quite been two posts a week. Of those posts 88 have dealt with topics in one of the many fields of science while 13 have been reviews of science fiction novels or movies. (Looking at these statistics I realize I need to do some more SF posts.)
Starting with the science we’ll begin by looking at some the events that took place in man’s continuing exploration of space. A lot happened both with robotic probes throughout the Solar System as well as preparing for future manned mission beyond low Earth orbit. In my opinion however the big story in space has bee the continued success of Space X corporation. (posts of 8Mar, 1Apl, 17May, 7Jun and 14Oct)
Space X, the Hawthorn California based commercial space launch company, succeeded in launching 18 of their Falcon 9 rockets in 2017 placing a variety of satellites into orbit including two resupply mission to the International Space Station (ISS).
In addition to launching 18 of their rockets Space X also able to land 16 of the rockets. (The two that were not recovered were not failures but rather missions requiring so much fuel that a recovery was not possible.) Indeed one of the Falcon 9 rockets that flew this year had already flown in 2016 and represented the first reuse and re-recovery of the Falcon 9.
With these successes Space X has proven beyond doubt its ability to reliably reuse the Falcon 9 and hopefully this will soon lead to a considerable reduction in the cost of getting into space. The image below shows the last Space X launch of 2017, one from Vandenberg Air Force Base and which gave the southern half of California a spectacular show.
On the interplanetary exploration side of space the biggest news came from the arrival of the Juno spacecraft at Jupiter (19Jul) along with the Cassini Spacecraft’s ending its mission to Saturn with a final plunge into the atmosphere of the planet itself (15Apl, 13Sept and 14Oct). Juno has already given us the closest views ever of the biggest planet in our Solar System and has allowed scientists to study phenomenon like the great red spot in greater detail. The image below is the Great Red Spot from the Juno spacecraft.
The Cassini spacecraft had already been orbiting Saturn for more than a decade sending back breathtaking images of the Solar Systems most beautiful planet (My opinion) and its mission was coming to an end due to lack of fuel. Because the data sent back by Cassini had indicated the possibility that two of Saturn’s moons, Titan and Enceladus might harbour life it was decided to send the probe to burn up in the giant planet’s atmosphere rather than risk contaminating those moons. The image below is one of the last from Cassini.
For manned space flight the year 2017 was more a waiting year as the ISS continued to be manned by Russian spacecraft but America is still hoping Space X and Boeing will begin test flights of their new manned capsules in 2018.
In the political / budget front President Trump ordered NASA to plan on a return to the Moon but there was no mention of money so no bucks, no Buck Rogers (16Dec).
In the science of Paleontology this has been a year of new discoveries along with the resolution of some long standing mysteries. New dinosaur species included the Patagotitan (16Aug), the Kayentapus (known only from its footprints) and the Sinosauropterys (both 28Oct). See images below.
For those of us who love Trilobites, and who doesn’t, we had the most detailed description ever of the digestive system of a trilobite (29Nov). There was also a paper examining the earliest known eye that was found on a fossil trilobite (9Dec). The image below is the fossil trilobite with the earliest known eyes.
To me however the biggest news in paleontology came from a paper examining the anatomy of the ancient extinct creatures called hyoliths, small conic shaped fossils whose taxonomic place among living things had been a mystery for almost 200 years (15Jan). After studying and dissecting, yes they can dissect fossils, the best specimens of hyoliths it was found that hyoliths belonged in the same group of animals that contained the brachiopods. The image below shows an artist’s representation of a hyolith.
Now I’m a physicist by training so in the past year there were a lot of posts about new developments in that field. The detection of gravity waves at the Laser Interferometer Gravitywave Observatory (LIGO) probably being the most noteworthy (14Jan, 7Oct and 22Oct). In fact the observation of gravity waves won the Nobel Prize for the chief scientists at LIGO Rainer Weiss of the Massachusetts Institute of Technology (MIT) along with Kip Thorne and Barry Barish of the California Institute of Technology (Caltech).
Now the first two observations of gravity waves both came from the merger of two black holes and as you may guess aside from the gravity waves there was little else to see. The third detection on August 17th however was caused by the merger of two neutron stars resulting in an explosion so huge that it produced enough radiation to be picked up by a Gamma Ray satellite along with optical and radio telescopes. The fact that we can now integrate gravity wave observations with the observations of other astronomically instruments opens up entirely new ways of studying the Universe.
I also wrote two posts about new experiments to study the sub-atomic particles called neutrinos, the ghost particle of the atom. In particular I wrote about the design and construction of the Deep Underground Neutrino Experiment (DUNE) (30Jul and 2Dec). Now the DUNE experiment will use the Tevatron particle accelerator at Fermi-Lab to produce large streams of neutrinos that will travel beneath the Earth to a huge neutrino detector in an old gold mine outside of Lead, South Dakota. (Neutrinos interact so rarely that hardly any will be absorbed). The way the neutrinos change during the 2000km flight will tell us a great deal about this most mysterious of elementary particles. The image below shows the setup of the DUNE experiment.
Oh, and before I forget there was the post about my trip down to Sweetwater Tennessee to view the ‘Great American Eclipse of 2017’ (24Aug). It really was an awesome sight that I’ll never forget. The Image below is one of my pictures of the eclipse.
Now as I said earlier most of my posts have dealt with science but during the past twelve months I did get to review three SF movies and six novels, I even spend four posts describing what Science Fiction is in my opinion.
The three movies I reviewed were: Guardians of the Galaxy vol.2 (20May), Blade Runner 2049 (25Oct) and Thor, Ragnarok (15Nov). All of them were interesting but all of them had their faults as well. To my mind a really good SF movie is that rarest of gems that only comes around once a decade or so. Oh well, I guess maybe I’m just asking for too much.
The same is pretty much true of the six novels I reviewed. The novels were: Dark Secret by Edward M. Lerner (18Jan), New Moon by Ian McDonald (1Mar), Saturn Run by John Sandford and Ctein (12Apl), Death Wave by Ben Bova (31May), the Three Body Problem by Cixin Liu (30Aug) and Galactic Satori Chronicles Book 1: Earth by Nick Braker and Paul E. Hicks (27Sept). Each of these novels would appeal to some but the one I found most interesting and best written was The Three Body Problem by Cixin Liu. The image below shows the cover of the Three Body Problem.
Well this has been quite a long post but then it’s been a long year and a lot happened. I’m sure that next year will be just as interesting; I hope you’ll stop by on occasion to check out ‘Science and Science Fiction’.
I get comments about Posts on this blog several times a day and I want to thank all for you for both your encouragement and kind messages. I recently received one such comment from a visitor named Bianca who wrote in response to my post about Paleontology back in November 2017, “It’s nearly impossible to find experienced people on this particular topic but you seem to know what you’re talking about.”
Now I don’t want you to get the idea that I’m the sort of person who turns down flattery when it’s offered but there are a lot of people out there who have a much greater knowledge of Paleontology than I do. I know quite a few of them.
Bianca’s comment got me thinking however about all of the many places that people like her can go in order to see some truly beautiful fossils and learn more about the kinds of living creatures that preceded us on Earth. All too many people aren’t even aware that many of these places exist. So in this post I’m going to talk about some of them.
Now I live in Philadelphia, Pennsylvania and here in Philly we are fortunate to have the Academy of Natural Science, which has a very nice collection of fossils on display including the very first dinosaur skeleton discovered here in the United States. The image below gives an idea of the Academy’s hall of Dinosaurs.
Not far away in New York City and Washington DC we also have the American Museum of Natural History and Smithsonian Natural History Museum respectively. These museum’s are among the best in the world in terms of their fossil collections and I’ve visited them both on several occasions. The images below give just a taste of the exhibits that can be found at these museums.
O’k, so the big museums in the big cities have big collections but a lot of people can’t get to New York or Washington. Well other cities have museums as well. Chicago has its Field Museum, Pittsburgh the Carnegie Museum, Atlanta its Fernbank Museum of Natural History and Los Angeles has the La Brea Tar Pits Museum.
In addition to the big museums however there are also all of the parks that have fossil connections. The US National Park Service lists eleven Nation Parks, such as Dinosaur National Park, Florissant Fossil Beds National Park and even Grade Canyon National Park, where visitors can see many of the fossils that have been uncovered there. The link below will take you to a National Park Service site giving information on the eleven national parks with fossil connections.
We mustn’t neglect State Parks either. One park I’ve often visited is Poricy Brook State Park in New Jersey. The visitor center there has a nice fossil collection on exhibit along with instructions on where to go in the park to find your own fossils!! Caesar’s Creek State Park in Ohio is much the same, a nice exhibit and directions to the local fossil site. The image below shows a 62cm long specimen of a trilobite on display at the Caesar’s Creek State Park visitor’s center.
So far all of the museums I’ve mentioned have been in the United States but that doesn’t mean other countries don’t have museums with equally impressive fossil collections, far from it. The Natural History Museum in London has one of the world’s largest collections, including specimens collected by Charles Darwin.
The UK also possesses one of paleontology’s real jewels along England’s south coast; known to fossil hunters as the Jurassic Coast. The Jurassic Coast covers almost 250 million years of Earth’s history and so extensive are the fossils in this region that every little town has its own museum or visitor center displaying fossils discovered there. The image below shows just a bit of the Jurassic coast fossil location.
There are many websites dealing with the fossils of the Jurassic Coast, the one below will provide you with a list of some of them.
Other countries have their own museums as well. In Berlin there is the Museum fűr Naturkunde while there is the Jurassic Land Museum in Istanbul. Brussels boasts of the Royal Belgian Institute of Natural Science and Cape Town in South Africa has the Iziko Museum (they have a wonderful collection of fossils of human ancestors).
In recent years China has become one of paleontology’s hotbeds and the Zigong Dinosaur Museum has many of the latest discoveries on exhibit. And let’s not forget Australia where the National Dinosaur Museum displays specimens only found down under.
I hope by now you realize that there are Natural History and fossil museums almost everywhere, you just have to go looking for them. Be careful however, seeing all of those fossils may inspire you to start looking to find some of your own. I can give you some advice on doing that as well but that’ll be another post.
I know, I just wrote a post about paleontology a little more than a week ago (29Nov17) but there have been several interesting announcements including a big one that’s been 20 years in the making. I’ll start with the announcement that those of us who keep up to date on fossil news have been waiting for so long.
The nation of South Africa has for almost a century now been a rich source for fossils related to the evolution of our own species Homo sapiens. In particular explorers have made many important discoveries while searching the limestone caves in the northern part of the country.
In July of 1997, Professor Ron Clarke of the University of Witwatersrand in South Africa was exploring a cave about 40km northwest of Johannesburg from which he and his assistants had already discovered several foot bones along with leg bone fragments.
What they found was the almost complete skeleton of an Australopithecus female, aged about 30.The remains were named ‘Little Foot’ because of the foot bones Clarke had found earlier. Clarke speculates that the young female fell to her death in the cave approximately 3.67 million years ago.
Problem was that over the centuries dirt and other debris also fell into the cave encasing the fragile bones in hard rock that had to be removed VERY carefully so as not to damage the fossil. So Professor Clarke and the other paleontologists at Witwatersrand took their time, 20 years in fact and just this week the fully prepared skeleton was displayed to the public for the first time. The images below show Professor Clarke with “Little Foot’ along with a close-up of the skull and upper body.
How much ‘Little Foot’s’ remains will add to our knowledge of human evolution remains to be seen. The theoreticians are going to have to think about it for awhile but ‘Little Foot’ represents an enormous amount of data. And remember no one knows what else is waiting to be found in those caves in South Africa. I expect to hear about a lot more discoveries in the next few years.
A somewhat older fossil find, about 530 million years older, comes from Estonia and gives us our earliest evidence for the evolution of an eye. Now, not a refractive cornea type of eye such as humans and other vertebrates possess but rather a compound eye of the type that lobsters, crabs and insects use.
The evidence comes from a specimen of one of my favourite types of extinct animals, a trilobite. The fossil in question, see image below, has been analyzed by Professor Euan Clarkson of Edinburgh University. The pictures below show the entire fossil from above alone with a side view of one of the compound eyes.
According to Professor Clarkson the eye is remarkably modern, the only noticeable difference is the lack of a lens like structure. Although the animal probably had poor vision compared to modern insects or crabs it nevertheless could detect predators and obstacles.
My final fossil discovery for today lived during the Triassic period, about 245 million years ago, but concerns the line of animals that are the closest living relatives of the Trilobites, the Horseshoe Crabs.
A new fossil species of horseshoe crab has been discovered in the state of Idaho by a team of paleontologists led by Allen J Lerner of the New Mexico Museum of Natural History and Science. The shape of the animal’s shell, see image below, reminded the discoverers of the helmet of the famous villain Darth Vader from the ‘Star Wars’ series of movies so they decided to name their find Vaderlimulus.
Now Vaderlimulus is an important find, being the first known fossil horseshoe crab from the Triassic in North America but let’s be honest, it’s that name that got it publicity.
I came across a couple of interesting stories detailing new discoveries in the field of paleontology. The stories concern my two favourite kinds of extinct animals, dinosaurs and trilobites so I have to talk about them.
I’ll start with the article about trilobites. For those who aren’t familiar with these creatures from the beginning of multi-cellular life trilobites are arthropods, similar to crustaceans, spider and insects but much simpler in physiology. (See picture below showing trilobite anatomy) Trilobites lived from the beginning of the Cambrian period (about 550 million years ago) until the mass extinction at the end of the Permian period (about 250 million years ago). During that long stretch of time over 20,000 different species are known to have existed so trilobites are a fairly common fossil; I have quite a few in my collection.
But usually trilobite fossils consist only of the hard outer shell of the animal, the internal anatomy has decayed completely away. Only rare specimens show any of the ‘soft parts’ of animals as old as trilobites. And since trilobites are one of the earliest forms of complex life their internal workings could tell us a lot about how the nervous system, or circulatory systems or other internal parts evolved.
Now a group of researchers headed by Melanie Hopkins of the American Museum of Natural History have published a paper describing the earliest known digestive system of a trilobite. The specimens used in the study come from the Guanshan biota in the Yunnan province of China, a location that produces fossils of exceptional preservation. The fossils used in the study come from two different species, Palaeolenus lantenoisi and Redlichia mansuyi, that are common at the site.
Multiple specimens were literally dissected, imagine dissecting an animal dead for 550 million years, in order find their stomach and trace their alimentary canal. In trilobites the stomach, also know as the crop, is situated very close to the mouth beneath the glabella, see picture above. The researchers also discovered pairs of digestive organs on each side of the alimentary canal, which runs nearly the entire length of the trilobite. The image below shows some of the dissected specimens along with drawings of what was found.
The digestive system of trilobites may seem simple compared to that of modern arthropods but for their time these were highly evolved. This study has given us some of the details about how the internal workings of a very important group of animals developed.
The second story I’d like to discuss comes from France where the longest known trackway of sauropod dinosaur footprints have been excavated in the Jura Mountains near the village of Plagne. The Jura Mountains by the way is where we get the name of the Jurassic Period.
The sauropod dinosaurs are the familiar long necked, long tailed plant eaters who were the largest animals to ever walk on the Earth. The 155 meter long trackway contains 110 steps and the impressions range from a little over a meter to three meters in diameter. The image below shows the trackway.
According to the ‘Societe des Naturalistes d’Oyonnax’, a local group of amateur paleontologists who discovered the footprints, the trackway was made by a single animal approximately 35 meters in length with a mass of around 35,000 kilos. The animal walked with an average stride of 2.8 meters at a speed of about 4 kilometers per hour. The image below shows an artist’s representation of the sauropod dinosaur walking along the trackway while humans are beneath it.
With each new find by paleontologists we are learning more about the history of life on Earth. It is a history far longer and more extensive than the history of the single species we think is so important.
The science of paleontology has been a very active and exciting field of research over the past few years and this past month has seen the announcement of several new discoveries. I’ve chosen three items to discuss in today’s post.
The first discovery I’d like to discuss concerns new evidence about the appearance and skin colouration of dinosaurs. Now everybody knows that most of the dinosaur fossils that are found are just the bones of the animals. And you certainly can’t tell what colour a creature was from its bones. Impressions of the skin of dinosaurs are rare and those impressions with traces of skin colour rarer still.
Because of this fact for many years dinosaurs were usually portrayed as having rather bland colouration, normally just a shade of green. The illustration below from Sinclair Oil Company (Their symbol is an Apatasaurus) shows what we thought dinosaurs looked like in the 1950s and 60s. Notice how the animals are all green or gray and even on those with strips the strips are just a different shade of the main colour.
Scientists are a patient bunch however, they kept looking for evidence of soft tissue and there are a lot of fossils out there to find. Over the last twenty years a number of fossil specimens have been found that now tell us a great deal about dinosaur appearance. It turns out that some dinosaurs at least had either vibrant colours or elaborate patterns, or both on their skins, or feathers! Yes, we also now know that many dinosaurs were covered in feathers to keep them warm.
In fact a recent paper published in the journal ‘Current Biology’ describes how small theropod dinosaur from China called Sinosauropteryx, in addition to being feathered was also decked out in alternating dark and light bands similar to the way a raccoon looks. The image below shows what the animal looked like according to co-author Fiann Smithwick of Bristol University.
Doctor Smithwick and his colleagues came to their conclusions after an extensive study of three excellently preserved specimens of Sinosauropteryx. The specimens were not only examined under a microscope but the researchers also used cross-polarized filters to bring out the contrast in the colour patters. The image below shows one of the fossils used in the study as seen under cross-polarized light, the areas of light and dark pigmentation are evident.
This pattern of colouration is known as counter shading and is a common pattern in living animals. Doctor Smithwick suggests that the dark patches around the eyes may have served to reduce glare the same way that athletes today paint a dark stripe under their eyes.
The second news item I’d like to discuss is about the discovery of two-foot long footprints of a predatory dinosaur from Lesotho in southern Africa. While not as large as Tyrannosaurus Rex the theropod that made the footprints came from a much earlier time, the beginning of the Jurassic period about 100 million years before T rex.
According to paleontologist Fabien Knoll of the University of Manchester “Our finding corroborates the hypothesis that theropods reached a great size relatively early in the course of their evolution, but apparently not before the Triassic-Jurassic boundary.” Despite the fact that no remains of the animal have been found so far it is estimated to have been about 10 meters in length and has been given the name Kayentapus ambrokholohali. The picture below shows the footprints of Kayentapus ambrokholohali.
Finally, we don’t often hear about fossil discoveries from India so the discovery of a well preserved specimen of an ichthyosaur certainly deserves a quick mention. For those who don’t know ichthyosaurs were reptile versions of dolphins that lived during the time of the dinosaurs. Returning to the sea their ancestors had left behind these air breathing lizards evolved fins in place of legs and a fish like tail. The image below shows a typical ichthyosaur.
The specimen was discovered near the Indian city of Kutch in the province of Gujarat. According to Guntupalli Prasad of the University of Delhi the 5.5 meter fossil is believed to belong to the ichthyosaur family Ophthalmosauridae and lived between 90 and 165 million years ago. The photo below shows the ichthyosaur fossil as it was being unearthed.
With these and other exciting fossil finds coming to light on a regular basis this is obviously a good time to be a paleontologist.
The very word Dinosaur means terrible lizard and ever since human science realized that huge reptiles once dominated the Earth the search has been on for paleontologists to find the biggest, the most awe inspiring dinosaur of them all. The first specimens of Brontosaurus stunned the public with their size but they soon gave way to the Diplodocus who in its turn was outclassed and outmassed by the Seimosaurus. These huge long necked, long tailed sauropod dinosaurs have even been given the group name of Titanosaurs to convey their immensity.
Now a new contender for the title of world’s largest animal has been announced and named. Based on fossils discovered in the Patagonian region of Argentina, Patagotitan mayorum is believed to have measured more than 35 meters in length and to have possessed a mass of greater than 60,000 kilos, about 12 times the mass of the current largest land animal the African Elephant. The picture below shows the assembled skeleton of Patagotitan mayorum in a warehouse.
The bones of Patagotitan Mayorum were first discovered in 2014 by the Argentinean paleontologists Jose Luis Carballido and Diego Pol of Argentina’s National Scientific and Technical Research Council. The two scientists have spent the last three years carefully digging up and analyzing the bones before officially naming their prize. In addition to its extreme size the fossils of Patagotitan discovered are also an unusually complete skeleton and researchers hope this specimen will enable us to learn more about how the sauropod dinosaurs evolved into such behemoths.
As exciting as the announcement of Patagotitan Mayorum is I have to wonder why three different news stories insisted on proclaiming the find as “New Dinosaur bigger than T-rex”! That’s a bit like saying a new species of Elephant has been discovered and it’s huge “Bigger than a lion!” Yes, plant eaters are often considerably larger than their predators (Think Bison and Wolves) and T-rex is not the standard against which every dinosaur has to be measured.
Another important fossil discovery announced this past week concerns our own species and our closest relatives the great apes. Now to remind you, in the world today there are four species of great apes: chimpanzees, gorillas, orangutans and ourselves, along with one species of lesser ape the gibbons. That’s all that are left in the world today but 10 to 20 million years ago there were dozens of other now extinct species of ape in the world.
Recently a nearly complete 13 million year old skull of a baby ape was discovered in Kenya. Nicknamed ‘Alesi’ by its discoverer John Ekusi the creature was likely a fruit eating, climbing primate that resembled a gibbon. The image below shows the fossil skull of Alesi.
According to the study’s co-author Craig Feibel, chair of the anthropology department at Rutgers University in New Jersey, the age and location of this fossil make it very important. “The…locality offers us a rare glimpse of an African landscape 13 million years ago.” It is hoped that Alesi will tell scientists a great deal about how the great apes, including our ancestors, split off from the many species of lesser apes.
An examination of the unerupted adult teeth indicates that Alesi belonged to an already established genus of apes called Nyanzapithecus but to a new species that has been named Nyanzapithecus alesi.
The authors of the study are unsure how Alesi died but a layer of volcanic ash from a huge eruption that occurred in eastern Africa 13 million years ago covered the skull and it is possible that Alesi died in that eruption.
If you’d like to read more about the discovery of Alesi click on the link below to be taken to the Scientific American article.
Two new studies by two separate teams of paleontologists have been published recently giving new details into the appearance and behavior of everybody’s favourite extinct predator, Tyrannosaurus-rex, better know simply as T-rex.
The first study dealt with the question of whether or not T-rex may have sported a colourful coating of feathers on at least portions of its body. After all T-rex is a member of the line of dinosaurs that paleontologists are convinced are closest to, maybe even ancestors of the birds. There is also growing evidence that T-rex’s smaller relatives were in fact covered in insulating feathers, not flight feathers, insulating feathers to help keep the animal warm. (See my post of 16Dec2016 about a feathered dino tail encased in amber!)
With these facts in mind Professor Phil R. Bell of the University of New England in Australia led a team of researchers to examine all of the available fossil evidence to find an answer. Now because skin impressions of dinosaurs are very rare, especially T-rex, Professor Bell and his colleagues also examined the fossils of T-rex’s close and large relatives such as Albertosaurus, Gorgosaurus and Tarbousaurus.
Based on the evidence they found Professor Bell and his fellow paleontologists have concluded that T-rex and the other large Theropod predators did not possess feathers, not even over portions of their bodies. Like any reptile today, T-rex was covered in scales. Professor Bell theorizes that since large, active animals have more problems with overheating than keeping warm T-rex shed whatever insulation its smaller ancestors may have had. The picture below shows a fossilized impression of the skin of a T-rex.
The second study was conducted at the University of Manchester in England and led by Professor William Sellers. Professor Sellers and his team used biometric and biomechanical software programs to study how T-rex would have walked and whether or not T-rex could have run at all as depicted in all those recent Jurassic Park movies. (By the way I hope everyone is aware that T-rex actually lived in the Cretaceous not the Jurassic period!)
Now it a plain fact of nature that as an animal grows larger its weight increases much faster than the strength of its legs. This is why, relatively speaking, the legs of an elephant are considerably thicker than the legs of your dog or cat. Now a T-rex is even heavier than an elephant, and remember T-rex only has two legs on spread its weight on! The possibility that T-rex might have difficulty walking let alone running has to be considered.
Professor Sellers and his colleagues used the latest software biomechanical modeling programs to do just that. Earlier studies had suggested that T-rex might have been capable of speeds as high as 50kph but the new research provided strong evidence that even half that speed would cause ‘unacceptably high skeletal loads’ on the bones in T-rex’s legs.
It appears then that these two recent studies reinforce the picture we had when I was a child of T-rex being a big lumbering reptile. I’m going to try to imbed a short video provided by Professor Sellers and his team showing some of the modeling that they used in their analysis. The link below that will take you to the University of Manchester’s official announcement of the research.
Now, it was just a week ago (15 July 2017) that I posted about my first fossil collecting trip of the year and I’d like to close with a nice little story about keeping your eyes open and maybe you too can make an important fossil discovery.
Jude Sparks, a 10-year old boy who lives in Las Curces, New Mexico was recently playing in his own backyard when he spotted something eroding out of the ground that he thought was the skull of a cow. Doing a little digging Jude quickly realized his skull was too large to be a cow’s. While it was still in the ground, Jude showed what he found to his parents who contacted paleontologists at New Mexico State University.
What Jude had actually discovered was the 1.2 million year old skull of a Stegomastadon, a relative of the more famous Mastodon. The scientists have excavated the skull and hope that more of the animal’s remains may be buried nearby. The picture below shows Jude with his find.
A big part of science is really nothing more than keeping your eyes open and knowing enough to be able to say, ‘Hey, that looks different. I wonder what it is?”