E R Matheau-Raven (UK) Amber is the hardened resin of coniferous and angiosperm trees. Resin should not be confused with sap, which is a product of photosynthesis that consists of sugars, water and dissolved minerals. The sticky extrusive mass that comes from a cut on a pine tree is resin. Under the proper conditions, it undergoes certain physical and chemical changes that turn it into amber. If resin has hardened in recent times, it is called copal. Columbia, in South America, has extensive copal deposits. Presently, certain trees produce large quantities of resin; the Kauri gum from New Zealand (Agathis australis), the Sundarac from Australia (Tetraclinis articulata), the Gum Arabic tree from Africa (Acacia arabica)and the Algarroba tree from South America (Hymenaea courbaril. It was trees like these that produced the resin that often trapped unsuspecting insects and even some slightly larger animals. Like ﬂy paper, the more the animal struggled to get free, the more entangled it became. Fig. 1. Caddis fly: Order – Diptera. Often, the origin of the amber can be derived visually from the amber itself. Baltic amber may have a cloudy appearance, due to air bubbles and also has a high percentage of Succinic acid, as much as 8% by weight. It is a high-molecular compound of organic acids and has been produced as a result of fossilisation of the resin from the pine, Pinus succinifera. This tree was prospering in the Baltic area 40 to 45 million years ago. Fig. 2. Ant (worker): Order … Read More
S M Bowerman (UK) Sharks of the genus Hexanchus belong to the family Hexanchidae and are more commonly known as six gilled sharks or cow sharks. They are well known for the difference in shape between teeth of the upper and lower jaw. They are first recorded in the Jurassic. Smart (2001) states that Hexanchidae are represented in the English late Cretaceous by two species: Hexanchus microdon and H. gracilis, both species being known only from rare isolated teeth. I collected a single specimen of H. gracilis, which is the subject of this short article. It was found at Hunstanton, in Norfolk in the UK (TF 673414), from the Upper Cretaceous Lower Chalk, Middle Cenomanian, Varians Chalk, Schloenbachia varians zone. Fig. 1. The striking cliffs at Hunstanton (picture courtesy of Andrea Clark). It is an incomplete specimen from the lower jaw. The specimen shows only two cusps of a possible seven. These appear to be accessory cusps. The posterior aspect of the specimen is not preserved therefore the principle cusp is not seen. The cusps show no signs of serration and the specimen remains in chalk matrix with the lingual aspect uppermost. The root is rectangular and slightly convex. Tooth width is 5mm, and its height is 3mm. Fig. 2. Hexanchus gracilis (Ref. No. H/619). Further reading Fossils of the Chalk: Palaeontological Association Guide No 2 (2nd edition), edited by Andrew B Smith and David J Batten, The Palaeontological Association, London (2002), 374 pages (Paperback), ISBN: 0901702781 References Smart, P. … Read More
E R Matheau-Raven (UK) Florida has one of the world’s richest fossil deposits of both terrestrial and marine origin, encompassing over 2,000 known fossil locations. The state is famous for its Pliocene/Pleistocene fossil fauna but also has a rich and diverse Miocene heritage, plus its coastal waters abound with giant Carcharocles megalodon shark teeth, much prized by fossil divers for their value. Fig. 1. Tapir lower jaw. The Thomas Farm site in Gilchrist County, North Central Florida has the largest Miocene mammal deposits east of the Rocky Mountains. It was discovered in 1931 after locals reported what they thought was an Indian burial site and has, for the last 70 years, continually given up its secrets. The fossils from here are dated at 18 million years old and are typiﬁed by many types of mammal, such as the early three-toed horse Nanippus. Fig. 2. Horse upper molar: Equus sp. Florida began to form by a combination of volcanic activity and marine deposition along the northwest portion of Africa over 500 million years ago during the latter part of the Cambrian Period. At about 300 million years ago (during the Upper Carboniferous), the time of the formation of the supercontinent, Pangaea, Florida was sandwiched between what were to become North and South America and Africa. Near the Triassic/Jurassic boundary (210 million years ago), Pangaea began to divide into two major continents, Laurasia (North America, Europe and parts of Asia) and Gondwana (South America, Africa, India, Australia and Antarctica). Fig. 3. Tapir … Read More
Patricia Vickers-Rich , Peter Trusler, Steve Morton, Peter Swinkels, Thomas H Rich, Mike Hall and Steve Pritchard (Australia) The “road map” allowing (time) travellers to move across more than 1,000 million years in Namibia is recorded in the rocks of this land. And, it is on display in several museums in Namibia – in Swakopmund, Windhoek, Rosh Pinah and Farm Aar. The old part of the road In drafting the early section of this map, Southern Namibia has been a key region for understanding some of the sights our time traveller will come into contact with, some being the weird organisms called Ediacarans. Since the early days of the twentieth century, when geologists, such as Paul Range, and German soldiers occupying isolated outposts in the Aus region of Southern Namibia, some of these strange fossils were reported. These were the first ‘large’ multicellular organisms that prospered on planet Earth before the development of true animals, and amongst them were the tiny cloudinids. Their fossils are preserved in the thick rock sequences that can be seen along the “time road” in Southern Namibia. These showcase a time in the history of life when there were fundamental and pivotal changes in life occurring, with life transitioning from an enigmatic biota to what we consider normal today. And, at a number of museums in Namibia, including the Swakopmund Museum and the Namibian Geological Survey in Windhoek, several of these intriguing organisms are on show – such as the soft-bodied Ernietta, Pteridinium and Rangea,and … Read More
Ken Brooks (UK) The beach from Rocka-Nore to Pett Level is rich in fossil evidence. Even the most insignificant fossils are important because they provide clues that enable us to reconstruct the ancient environments of this area. Between 100 and 140 million years ago, much of southern England was covered by lakes and lagoons. Rivers flowing from the London area and the west deposited great quantities of sand and silt on extensive flood plains. Molluscs, fish and freshwater sharks lived in the lakes and rivers, while the land was dominated by crocodiles, turtles and dinosaurs. Fig. 1. The Hastings coastline today. Eventually, their fossilised shells, scales, teeth, bones and footprints were preserved in the layers of sediment. Carbonised plants, such as horsetails, ferns, cycads, conifers and tree ferns, indicate that the summers were hot and dry (with frequent fires), followed by wet and humid conditions in wintes. Millions of years later, when Africa collided with the European plate, southeast England was pushed upwards into a vast dome-shaped structure, known as the ‘Wealden anticline’. Since then erosion has removed many layers of rock and exposed the sandstones and clays which now form the cliffs between Hastings and Pett. Fig. 2. Hastings during the Lower Cretaceous (© Stuart Handley). Bones and footprints of Iguanodon are among the most common dinosaur remains, although other very interesting fossils have recently been found in the Hastings area. These include the spines and vertebrae of Polacanthus, a tooth from Baryonyx and quillwort plants still in their … Read More
Alister Cruickshanks (UK) The Norwich Crag at Easton Bavents, Southwold in Suffolk is one of the only locations where mammalian remains from the Pleistocene Epoch can be found, in situ, at an accessible location in the UK. The Norwich Crag splits the Antian and the Baventian. At Easton Bavents South Cliff, the Norwich Crag Shell Bed is missing. Instead, there is a ﬁne gravel layer with laminated clay and sand, which yields occasional remains. This bed is equivalent to the Lower Shell Bed of the North cliff at Easton Bavents, One of the latest theories suggests that this was once a pre-historic fast ﬂowing river, which ﬂowed into a larger estuary that was present at the North Cliff during the Pliocene Era. The North Cliff itself has a stone layer above the Norwich Crag Shell Bed. This bed comprises three main bands: the upper, middle and lower beds, but varies considerably along this stretch of cliff. The Norwich Crag Stone bed is directly below the Baventian Clay, both of which are from the Baventian stage which is 1.55 to 1.6 million years old, from the Pliocene Era. The Norwich Crag Shell Bed is Antian in age, which is 1.6 to 1.7 million years old. Fig. 1. Fine gravel layer with laminated clay and sand. A complete lower mandible of a walrus was discovered in situ after high tides during 1993, by my father and me. At this time, the specimen could not be fully identiﬁed and spent ten years at … Read More
Mike Thorn (UK) If you ask someone to think of Oxford, they will not usually picture warm tropical beaches and azure coral seas. However, go back to the middle Jurassic and you would be hard pushed to find a dreaming spire or student on a bicycle anywhere. At that time, around 160 million years ago, Oxfordshire lay beneath a shallow, tropical seaway at about the same latitude that the southern Mediterranean occupies today. Over the course of the middle Jurassic, this seaway varied in depth, but remained close to nearby land masses from which a lot of sediment was derived (Fig. 1). A great thickness and variety of limestones, sandstones and clays were deposited over several tens of millions of years. Fig. 1. Southern England during the middle Jurassic, 160 million years ago. During the nineteenth and early twentieth centuries, there were many working quarries in the Oxford area, exploiting the abundant clay and limestone for the brick and building stone industries. Quarrymen were frequently paid to look out for fossils and these turned up in abundance, fuelling the academic debates on evolution taking place at the time. Fig. 3. Geological Context for Kirtlington Quarry and Dry Sandford Pit. Sadly, many of these quarries have now been filled in and, for the casual fossil hunter in Oxfordshire, it might seem that there are now few opportunities to collect. However, Kirtlington Quarry and Dry Sandford Pit are two old quarries which are open to the public and at which there is … Read More
Ken Brooks (UK) This is the first of three articles on the geology and fossils in the cliffs and foreshore to the east of Hastings. This one is intended as a field trip. The geology here is all Lower Cretaceous and is some of the best in Britain if you are interested in this period of time. Follow the Hastings seafront eastwards to the ‘Old Town’ and the famous ‘net shops’ in Rock-A-Nore Road. Below the high, sandstone cliffs of the East Hill, you will find the Fishermen’s Museum, the Blue Reef Aquarium (a sea-life centre), a large car park and public toilets. This field trip begins at the last stone groyne and continues along the beach towards Ecclesbourne Glen, nearly one kilometre (half a mile) to the east. The massive sandstone cliffs of the Upper Ashdown Formation are overlain by the shales and sandstones of the Wadhurst Clay. A distinct junction between one horizontal bed of rock and another often marks a period of erosion. This may have been followed by a change in the environmental conditions where a different grade or type of sediment was deposited. In this area, the lower part of the cliff is hidden under a scree slope of broken rocks, but there is one small exposure in situ at beach level. Here, there are flattened branches of carbonised wood lying horizontally within a silty mudstone. These were probably washed into a river or lake, then later covered and compressed by sedimentary layers. The leaves … Read More
Ken Brooks (UK) During the Lower Cretaceous period, between 110 and 145 million years ago, Britain was part of the European land-mass. Southeast England was covered by meandering rivers, extensive ﬂood-plains, lakes and lagoons which extended across to central France. Rivers ﬂowing from the London Uplands and the west brought huge quantities of sand, silt and mud, which were deposited over the whole area. Fig. 1. Starlight Cove These sediments later became the sandstones and clays of the Ashdown Sandstone and Wadhurst Clay within the Hastings Beds. Structures in the rocks, combined with fossil evidence, can be used to reconstruct the ancient environments and communities of this period. For example, the siltstones, clays and sandstones have preserved features such as river channel and ﬂood plain deposits, as well as a rich variety of fossilised plants and animals. Fig. 2. An infilled river channel. The carbonised remains of horse-tails, ferns, cycads, conifers and tree-ferns indicate that Southern England had a sub-tropical climate with seasonal rainfall, perhaps like the Mediterranean today. Freshwater sharks and shellﬁsh lived in the lakes and rivers, while the land was dominated by crocodiles, turtles and dinosaurs. Today, their scales, teeth, bones and footprints may be found along the stretch of beach between Rock-a-Nore and Pett Level. Fig. 3. Crocodile tooth: Goniopholis. Around 100 million years ago, the great weight of the sediments, combined with geological faulting, resulted in a gradual subsidence of the southeast. As a warm, shallow sea began to cover most of England and northern … Read More
Tony and Anna Gill (UK) The best time to look for fossils in Dorset is after heavy rain and winter storms. These conditions make the cliffs unstable and collapse. High winds produce rough seas, which wash the mud away, leaving the nodules that contain the fossils exposed on the beach. The beginning of November 2005 saw a period of heavy rain and strong winds. This stormy weather continued for several days and on 5 November gale force 10 winds, before a high tide, exposing new material (Fig. 1). Fig. 1. A large landslip, approximately four hundred metres east of Charmouth, contains most of the best fossil horizons. This slip is illustrated with the sea crashing into it (Fig. 2). The large stones in the picture below do not contain any fossils. If they did, they would not be there. The best place to look for smaller fossils is around these large stones. Some of the pyrite ammonites found here can be up to 25cm to 30cm in diameter. Fig. 2. The storm crashing against the cliffs at Charmouth. The flat stones, which are from the Obtusum Shales, sometimes contain the ammonite Asteroceras Planicosta and usually the smaller ammonites Promicroceras Planicosta (Fig. 3). Fig. 3. Charmouth was the seabed in Jurassic times, some 195 million years ago. The football shaped and sized, Stellare Nodules, when broken, contain calcite crystals. Occasionally though, an ammonite can be found inside the larger ones. These ammonites can be up to 50cm across, but unfortunately, most … Read More
Dr Richard J Hubbard (UK) Introduction The Thanet Anticline is an uplifted area forming the northeast corner of Kent and is home to the four coastal towns of Birchington, Margate, Broadstairs and Ramsgate (Fig. 1). Historically, the area has been known as the Isle of Thanet and, in this article, I will look at sediment deposition and erosion around the upstanding anticlinal structure and how shorelines have shifted during the past two thousand years. I will finish with some thoughts about how shorelines might look one hundred years from now. The article is based on material drawn from three guidebooks published by GeoConservation Kent, written by Geoff Downer and myself (see below). Fig. 1. The Isle of Thanet. Sketch map of northeast Kent to show the geography of the Wantsum Channel at the time of the Roman occupation. Today’s shoreline is superimposed with some medieval settlements added for orientation. The Isle of Thanet is elevated and forms an ‘island’ because of the underlying structural geology. Note the location of the offshore seismic line published by Ameen (1995), on which the cross section of Fig. 4 is based. (Figure 87 from The Smugglers Trail, Hubbard & Downer, 2021.) This article has also been written to accompany a book review that was recently published by Deposits (see Book review: The Smugglers Trail – Geology of the Thanet Coastline from Broadstairs to Cliftonville, by Richard Hubbard and Geoff Downer). Thanet has been a high standing area for more than 300 million years and … Read More
Helen Gould (UK) Chemistry is the key to identifying the source of a meteorite. The commonest rock in the Solar System – and on Earth – is basalt. Erupted at mid-ocean ridges and many hotspot volcanoes, it also floors the oceans. However, each of these situations can be identified as geochemically different from one another. Some meteorites have geochemical signatures associated with individual asteroids, being either enriched or poor in specific minerals. The ratios of their minerals are plotted against one another, then the shape and co-ordinates of the plots are cross-referenced to a database. This process has allowed distinct groups of meteorites with similar geochemistry to be identified, suggesting that the meteorites in each cluster plotted came from the same source. There are five sub-groups of achondrites of various chemical composition, including eucrites, diogenites, SNC, lunar achondrites and ureilites. The name means they don’t contain chondrules. Most are of igneous origin, but lunar achondrites resemble fragmental sedimentary rocks. The only “weathering” on the Moon comes from impacting meteorites, but this breaks up rocks and reforms them into breccias – jumbles of jagged fragments fused together. Eucrites Eucrites are basaltic meteorites containing low-calcium proxenite and plagioclase feldspar with metallic iron, troilite (iron sulphide) and silicates. They probably all crystallised at or just below the surface of their source bodies. Fig. x. Eucrite. Diogenites Diogenites consist of calciumpoor pyroxenite, which is an igneous rock resembling the ocean crust. Fig. x.. Diogenite. SNC SNC meteorites have been identified as coming from Mars. … Read More
The Crowood Press are really developing a nice little series of books on the landscape and geology of select regions of the British Isles, and Tony Waltham’s addition to the series about the Peak District is well worth a read. This new one follows the same format as the others – beautiful, full colour photos and diagrams, a fascinating chapter on each of the important geological and geomorphological aspects of the area (including buildings and industry), and an author who knows his stuff and can write it down with an easy and authoritative style.
Thomas H Rich and Patricia Vickers-Rich (Australia) Whether they had horns or not, the ceratopsian “horn faced” dinosaurs are distinctive, not only from other dinosaurs, but all other vertebrates as well, in the structure of their skulls. In addition to the horns, another element of their skeleton, the lower arm bone (called the ulna or elbow bone), unexpectedly is so distinctive that it has provided clear evidence that, 130 million years ago, these very ceratopsians were living in Australia. Prior to that discovery, the ceratopsians were known almost exclusively in the Northern Hemisphere. Just over a century ago, a toothless lower jaw found in Patagonia, Argentina was named Notoceratops, “the southern horned face”. The last time that fossil was seen was a decade later when the world-renowned dinosaur authority, Fredrich von Huene, studied and redescribed that fossil and agreed unreservedly that it was a ceratopsian. Illustrations of that bone strongly support its correct identification as a ceratopsian. However, unfortunately, von Huene is the last person known to have laid eyes on it, and the fossil cannot now be found. Thus, the only ceratopsian previously thought to have come from the Southern Hemisphere, disappeared. When the Victorian dinosaur ulna, which is the subject of this article, was first found at the base of the Arch near Kilcunda (Fig. 1) by Mike Cleeland, Tom’s first guess was that it was some kind of carnivorous dinosaur or theropod. This was because it was a short, stumpy bone, which is so characteristic of the … Read More
Lutz Andres (Germany) The giant-toothed ‘Megalodon’ shark (Carcharocles megalodon,) is one of the most impressive extinct creatures to have excited our imagination, and its fossilised teeth are one of the most desired objects in the fossil collecting world. Fig. 1. Carcharocles megalodon. A lot of collectors and scientists believe that Megalodon is closely related to the Great White shark (Carcharodon carcharias), because of their similar teeth, which are large, triangular and serrated shape. However, that point of view is too superﬁcial. There are a few clear differences in the tooth morphology. In addition, they had apparently different kinds of nutrition and their dental weaponry suggests different hunting strategies. A few obviously different tooth characteristics between such closely related species will be described and discussed below. Different root shapes The root branches of the upper and lower anterior teeth of all giant-toothed sharks (Otodontidae) are elongated to resemble a ‘V’ or ‘U’. The roots of upper anterior teeth in Great White sharks are often nearly rectangular, without well-developed root branches. When the Great White shark attacks and bites its prey, the lower anterior teeth are the ﬁrst to penetrate the body, and then the shark closes its jaws. After that, it starts immediately to shake its head in a semi-circle shape, to rip ﬂesh out of the body, mainly with its upper anterior teeth. The pressure on these upper anterior teeth is applied laterally. Therefore, the roots have wider surfaces to absorb the laterally arising forces. Fig. 4. 1 and 3 … Read More
Byron Blessed (UK) 9:30am, Saturday, 15 April 2006. I set off with my fossil- hunting party from my shop “Natural Wonders Ltd” on Grape Lane in Whitby. The weather was overcast but ﬁne, and bright enough for the sun to break through later in the day. As I led the 15-strong party up the famous Whitby Abbey steps and along the Cleveland way to Saltwick Bay, no one could have anticipated this would be the day that I would find the best fossil I have ever collected. Fig. 1. Byron and faithful sidekick investigate the rock further. My fossil-hunting trips are really designed for the complete beginners: those who don’t know what they are doing, who have no idea about the safety issues involved in fossil collecting, and certainly have no idea what type of rocks to look for. Therefore, I had designed this trip to suit these needs, so that people can then go out and “do it themselves”. The great thing about fossil collecting is that you never know what you’re going to ﬁnd when you get onto the beach. So, after a run through of the “golden rules of fossil collecting” (tides are dangerous, cliffs are dangerous, bring the suitable equipment), it was straight into the shingle to search for the nodules containing the best ammonites. Fig. 2. One freshly excavated croc skull. Our return trip to Whitby is always along the foreshore past Saltwick Nab and under the East Cliff (also known as “the Scaur”). It … Read More
This is an ambitious little field guide, which aims to allow amateurs to identify basic rocks and rock formations, for the first time, in a systematic way., as it says: “… using only careful observation, a magnifying glass, a pocket knife – and a bit of patience”.
Helen Gould UK) What are meteorites? Lumps of rock left over from the formation of the solar system or “chipped off” planets during major impacts can become trapped in the Earth’s gravitational field and fall as meteorites. The three main types are iron, stony and stony-iron. All of these are discussed in this article. In particular, I consider two important questions: Why are they so important? Because they represent the growth (accretion) of planets, they carry clues to our Solar System’s formation.How do we know we are dealing with a meteorite? Like other rocks, meteorites record events. Most of their minerals are familiar but some have higher or lower concentrations than rocks found on Earth, suggesting an extra-terrestrial origin.Irons Fig. 1. Iron meteorite. Most contain 7-15 wt % of Nickel (Ni) metal, with traces of other minerals. At room temperature, instead of a single mineral, this forms a Widmanstätten structure, whose intergrowth lamellae show two different minerals, one with about 40% Ni, the other with only about 5% Ni, and indicate slow cooling from greater than 700°C. Iron (Fe) meteorites have usually been completely melted, proving they formed in asteroid cores. So even asteroids are differentiated – like the major planets – with a core and mantle which solidified slowly. Widmanstätten patternsAlso known as Thomson structures, these are figures of long nickel–iron crystals, found in the octahedrite iron meteorites and some pallasites. They consist of a fine interleaving of kamacite and taenite bands or ribbons called lamellae.Stony-irons Stony-iron meteorites probably … Read More
I like local geological guides, which aim to get you out and about, visiting areas you might not have known are worth a daytrip. And this is a good example. I sat down and read it cover to cover, as it is only 90 pages long. And I now really want to visit this bit of Kent coastline. Largely concentrating on the Upper Cretaceous Chalk, this guidebook explains and illustrates what seems to be some marvellous geology that can also be explored during what could be a lovely day out on the beach.
After having favourably reviewed the first two books in this three part series, I must admit I was very much looking forward to the publication of this last one. And, of course, I wasn’t disappointed. This is the third in a series of guides to safe and responsible fossil collecting along (this time), the East Dorset coast from the Chalk cliffs at Bat’s Head, across what are some of Dorset’s more remote coastal locations, to Hengistbury Head.
Dr Paul D Taylor (UK) There’s a small Cambrian trilobite (Fig. 1) that is collected in copious quantities from a site in the Wheeler Amphitheatre of Utah. Sold just as it is or mounted in jewellery, this trilobite lacks a common name and goes by its scientific name. In its fullest form, this is Elrathia kingii (Meek, 1870). But what exactly do the different parts of the name mean? How did Elrathia kingii – and other species of fossils – receive their names in the first place? And what are holotypes, lectotypes, neotypes and topotypes? In answering these and related questions, this article focuses on the procedures used by taxonomists when describing and naming living and fossil organisms. Fig. 1. The Cambrian trilobite species from Utah, now called Elrathia kingii (Meek, 1870), was originally named Conocoryphe kingii by Meek in 1870. Fifty-four years later, it was made the type species of the new genus, Elrathia by Walcott. Meek’s name is written in brackets because of this change in genus. Along with living organisms, the formal names of fossils employ the binomial system introduced by the Swedish naturalist, Carl Linnaeus in 1735. A genus name is followed by a species name, the latter sometimes referred to as the trivial name. Both are by convention always printed in italics, the genus name with a capital first letter and the species name with a lower case first letter. Unfortunately, newspapers all too often incorrectly print generic names with a lower case first letter. … Read More
Helen Gould (UK) As we saw last time (Plate tectonics (Part 1): What are they?), the Earth is a pretty dynamic place, with tectonic plates moving about on the surface, driven by convection cells in the upper mantle. But producing a workable theory, which combined most of the observations of geological evidence, took years. It was known that the centres of continents were extremely old, and that some areas around the continental “cratons” didn’t seem to belong because they contained completely different types of rocks. Combining continental drift with seaﬂoor spreading and mantle convection currents produced the idea of plate tectonics, and provided an explanation for the odd rocks on areas fringing some cratons. These “microplates” had come from other areas of the Earth, where different geological processes had produced different rock types. The role of density in recycling: oceanic and continental crust The physical features of the ocean basins and continental mountain ranges are known as the “crustal dichotomy” (splitting of the crust into two equal parts), and because these types of feature are essentially dissimilar, they have their own rock types. Basalt is the commonest rock both in the Solar System and on Earth, where it forms the ocean ﬂoor, along with various sedimentary rocks deposited underwater which make up another 5% of the total oceanic crust. Continents typically consist of coarse-grained rocks related to granites, which solidify below ground. Comparing similar-sized pieces of basalt and granite in the hand will establish obvious physical differences between them. Basalt’s … Read More
Mike Thorn (UK) In his book, “Architects of Eternity: The New Science of Fossils”, Richard Corfield coins the term “reluctant palaeontologists”. He has in mind those chemists, biochemists and biologists who use the techniques and skills from their own disciplines to shed new light on our ideas about evolution. Ross Barnett, of the Department of Zoology at Oxford, might well be considered to be in this category. A biochemist by training, he has recently co-authored a paper on the DNA of three extinct cats which has helped to lay to rest some of the arguments about the feline family tree. Fig. 1. Smilodon skeleton. Ross came to Oxford in October 2002, to work on a PhD, after completing his biochemistry degree at Edinburgh. His supervisor, Professor Alan Cooper, was interested in cat genetics and had managed to raise funds to carry out research into the relationships of several extinct cats. In particular, there were questions about where the sabre-toothed cats, such as Smilodon and Homotherium, fitted in. Fig. 2. Ross Barnett in his office. As Ross explained: There has been a lot of study done on these animals. For example, there is a huge collection of thousands of individuals of Smilodon from Rancho Le Brea in Los Angeles, so they’ve been really well characterised from their morphology. What the palaeontologists had concluded from this was that there was a split at the base of the cat family tree between the group that goes on to form the sabre- tooths – … Read More
Jon Trevelyan (UK) If Yorkshire really is ‘God’s Own County’, then clearly the Almighty is an enthusiastic geologist. Just how lucky is the Yorkshire man who, on the same day, can see some of the best and most varied geology in the world, set out in glorious coastal and mountain … Read More
This small, yet informative, booklet takes you on a four-mile walk to 13 sites and through 15 million years of Earth history. The Mortimer Forest Trail is a geology trail in Shropshire that is famous for its outstanding fossils and varied geology. The trail mostly examines Silurian formations such as the Wenlock and Ludlow series.
James O’Donoghue (UK) Did the destruction of forests by mammoths make the Pleistocene Ice Age even colder? It’s an extraordinary prospect. Yet, a leading fossil mammal expert thinks they did just that. Over many tens of thousands of years, mammoths and straight-tusked elephants ate their way through vast tracts of the world’s forests. Trees exert a buffering effect on global climate – take them out and face the prospect of hotter and colder extremes. Mammoths may have turned cool Ice Age periods into freezing ones. Straight-tusked elephants may have made temperatures rise during interglacials. Both types of elephant had all but vanished by 10,000 years ago, never to return. Since then, forest cover has increased sharply while the climate has been unusually mild and stable. Could the two be linked? Humans chopping down forests are now exerting at least as profound an effect on the world’s ecosystems as the mammoths had on theirs. By comparing the destruction wrought then and now, an alarming prospect emerges. Are we in the very process of making our own climate as volatile as that of the extinct elephants? Cores drilled from undisturbed glacial ice in Greenland and Antarctica have provided a wealth of information about almost constant shifts in the Earth’s climate over the past few hundred thousand years. Climatologists will tell you that we live in an interglacial period, in a world that is still going through an ice age that started 1.8Ma with the onset of the Quaternary period. (When I refer … Read More
Dick Mol (The Netherlands) Introduction In 1874, the ﬁrst known mammoth remains were brought ashore, trawled off the coast of the province of Zeeland, The Netherlands. Fishermen, fishing for flatfish, caught these fossils as bycatch in their nets. (A bycatch is a fish or other marine species that is unintentionally caught while catching certain target species and target sizes of fish, crabs and so on) A museum associate in Middelburg described these bones in an extensive research report. This resulted in a sound basis for ongoing study of the lost life found on the bottom of the North Sea between the Netherlands and the British Isles, about two million to 10,000 years ago. For years the fishermen brought their bycatches ashore. Usually, these were large bones and teeth, both of mammoths and whales. In fact, the North Sea bottom used to be a vast plain during the Ice Age with mammoths walking around in large herds and this area must have been a paradise for large mammals. Apart from the mammoth remains, other species like wild horses, giant deer, deer, lions, bears, wolves, rhinos and others have also been found. Fig. 1. An upper molar of a woolly rhino, Coelodonta antiquitatis (BLUMENBACH). Thousands and thousands of woolly rhino remains have been fished from the southern bight of the North Sea between Britain and the Netherlands. Thousands and thousands of these remains ended up in Naturalis, the National Natural History Museum in Leiden. Today, this museum holds one of the largest … Read More
Bob Williams (UK) In the previous part of this article (see Early Eocene London Clay deposits at High Ongar, Essex (Part 2)), I located the beds exposed at High Ongar in Essex (TQ 556809) within the general, stratigraphic framework of the London Clay. I also argued that examining the habitats in which families of crustacea live today provides clues about the sort of habitats that may have existed when the London Clay in the pits at Aveley in Essex and Ongar (TL 562024) was deposited. In this part, I will continue this comparison using modern lobsters, shrimps and other animals to provide clues about the habitats that may have existed at Ongar and at various other London Clay sites when their fossil relatives were alive. I will also show how one can locate a site like Ongar within the stratigraphic column. Fig. 1. Estimated position of the clay exposures at High Ongar Essex and nearby Aveley, showing the London Clay sedimentary deposits. At this point, it is worth bearing in mind the conditions in which the London Clay deposits are believed to have been laid down. London Clay is not one, uniform deposit. There are a number of sedimentary horizons within the deposit, each horizon reflecting the environment in which it was formed. Broadly, the London Clay is thought to have been laid down in a marine environment influenced by a tropical or subtropical climate. Water depth is thought to have averaged about 200m, but would obviously have varied locally. … Read More
Those of you who have read a few of my book reviews will know that I love geo-guides to small geographical areas, rather than just the big geological scientific issues. In fact, there are lots of good UK guides like this one, to areas such as Dorset and Yorkshire, and many areas of Scotland and Wales, for example. And this is another excellent example of that genre.
Bob Williams (UK) I first encountered the geological deposit known as the “London Clay” when I accompanied a friend to an exposure of the stuff. He told me that it was good for collecting fossils. It was and I was taken aback by the quality and quantity of fossil material. However, I knew nothing at all about the geological details of the sediment. However, like all keen amateurs, I wanted to know more about the deposit. To the uninitiated, the name “London Clay” suggests a single, uniform deposit. However, in truth, it does not fit that description. The name is given to a sedimentary deposit that contains at least five different and distinctive horizons (referred to as Divisions A to E). They were laid down in early Eocene times (50 to 54Ma) in conditions that were particular to slightly different environments or habitats (I use the terms interchangeably in this article). In a non-scientific way, the London Clay environments can be compared to the environments found in an ocean such as the Indian Ocean. Fig. 1. Estimated position of the clay exposures at High Ongar Essex and nearby Aveley, showing the London Clay sedimentary deposits. In broad terms, it is possible to describe the Indian Ocean as having warm, marine waters, being subject to tropical or sub-tropical climates and containing particular life forms. However, a variety of individual habitats can also be found in the Indian Ocean. There are shallow waters, deep waters, coastal waters, reef systems, trench systems, rocky … Read More