Three-dimensional photographs of fossils (Part 1): Gastropods from the Paratethys Ocean

Dr Robert Strum (Austria) About 23Ma, the Paratethys Ocean covered a large area, including what is now the Vienna basin and Alpine Foreland. This mostly shallow ocean was a habitat for a large number of plant and animal species, which included numerous marine gastropods, some of which are discussed in this article. This is the first of three articles on three dimensional photograph of fossils. In this article, to give the reader a better impression of their volume and shape, the fossil shells have been photographed by using the stereoscopic technique I describe in Three dimensional photography of fossils (Part 3): Ammonites from the Northern Limestone Alps of Austria. Today, beautiful shells with various shapes and patterns, of recent marine gastropods, can be collected in large numbers along Mediterranean and tropical coasts. While this seems normal to us, finding marine molluscs in Austrian sandpits, far away from any ocean, is a little more surprising. Of course, the simple answer is that these shells are fossils from the ocean referred to above, which once covered what is now Central Europe. The fossils commonly originate from the Tertiary period, which lasted from 65Ma to about 1.8mya. More precisely, the fossils are from the Eggenburgian of the Miocene (23Ma to 5.3Ma), named after Eggenburg, a lovely village north-west of Vienna. (The Eggenburgian is a Lower Miocene stage of the Central Paratethys regional chronostratigraphic classification.) Fig. 1. Map exhibiting the position of Eggenburg in Austria and the arrangement of single sampling localities and related sights:1. … Read More

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Carbonate platforms and coral reefs: The Coralline Oolite of the Yorkshire Upper Jurassic – a prime source of palaeontological information

Keith Eastwood (UK) The Malton Oolite Member of the Coralline Oolite Formation (Corallian Group), as exposed in the Betton Farm South Quarry (TA00158555) at East Ayton, near Scarborough (Fig. 1), provides a wealth of fascinating palaeontological and sedimentological information. Examination of outcrops within this small quarry enables the geologist to reconstruct the palaeoenvironment of deposition of the Betton Farm Coral Bed, a localised system of patch, ribbon and framework reefs that developed during the Upper Jurassic. Fig. 1. Locality map of the Betton Farm and Spikers Hill quarries. Geological outcrops from BGS Sheet 54 (Scarborough) (1998), (Wright, 2001, p.157, fig.4.20). Total image © Joint National Conservation Committee; geological outcrop map – British Geological Survey © NERC. Redrawn and reproduced with permission. The lithology and textural characteristics of the Malton Oolite Member provide a sedimentological basis for the interpretation, but the fossil content adds definitive ecological and climatic insights. The Malton Oolite is the upper of two oolite members in the Coralline Oolite Formation (Fig. 2). The lower one, the Hambleton Oolite Member, is not seen in the Betton Farm Quarries (which consist of two quarries: Betton Farm North Quarry and Betton Farm South Quarry, north and south of the A170, respectively) but is fully exposed in the Spikers Hill Quarry (SE 980863) just 3km to the WNW (Fig. 1). This location is important in providing a regional depositional context for the Betton Farm deposits, even though the upper surface of the intervening Middle Calcareous Grit Member is a minor unconformity. … Read More

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Fossil folklore: Molluscs

Paul D Taylor (UK) The final article of this series on fossil folklore focuses on molluscs, excluding the ammonites, which were covered earlier (see Fossil folklore: ammonites in Deposits, Issue 46, pp. 20–23). Molluscs are second only to arthropods in the number of species living today and the resistant calcareous skeletons possessed by the majority of species accounts for their extremely rich fossil record. Most fossil molluscs belong to one of three major groups – bivalves (oysters, clams and so on), gastropods (snails and slugs) and cephalopods (ammonites, belemnites and so on). Added to these are a few minor groups, such as the monoplacophorans and scaphopods (tusk shells). Fossil molluscs are usually recognisable instantly as belonging to this phylum because of their close similarities with the shells of familiar species of modern molluscs. Some, however, are not quite so straightforward. These are more likely to have been the sources of fanciful stories about their origins and significance. Among the more obscure ancient molluscs are those dubbed ‘difficult fossils’ by Martin Rudwick in the context of the early history of palaeontology and doubts over the origin of fossils. They include the solid internal casts (steinkerns) formed by lithification of sediment enclosed by the shell and subsequent loss of the defining shell itself. In addition, there are some mollusc fossils – notably belemnite guards – that bear little resemblance to any living species, adding to their enigmatic nature. Belemnites: thunderbolts and Devil’s Fingers The first fossils I ever came across were belemnites … Read More

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Invertebrate fossils from the Lower Muschelkalk (Triassic, Anisian) of Winterswijk, The Netherlands

Henk Oosterink (The Netherlands) During the Muschelkalk part of the Ansian (240mya), the Central European area (Germany, Poland, Denmark, The Netherlands and north-eastern France) was covered by a shallow sea, referred to as the Muschelkalk Sea. While there were frequent regressions and transgressions (leading to both marine and terrestrial fossil being present in these regions), it is from this sea that the limestones from this quarry were deposited and in which most of the fossilised animals discussed in this article lived. The quarry in the Muschelkalk at Winterswijk, in the east of the Netherlands (Fig. 1), is especially well known for the skeletons, bones, footprints and tracks of Middle Triassic reptiles. I wrote about these in Issues 15 and 20 of Deposits. However, fossils of invertebrates, such as molluscs, brachiopods and arthropods can also be found. Included in the molluscs are bivalves, cephalopods and gastropods, and from the brachiopods, the Inarticulata are present. From the arthropods, there are Malacostraca, Merostomata and insects. Fig. 1. Lower Muschelkalk quarry near Winterswijk (Eastern Netherlands). Mollusca Bivalves Some strata contain a large number of moulds of bivalves. These are situated quite high in the profile and, if you find this level, it is important to split the rock along an irregular dark-grey line (Fig. 2). If you do this, you will find the moulds of the convex upper side of the separated shells on one slab, with the negative impression visible on the other. This makes clear that these are valves swept together by … Read More

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Giant trilobites and biotite nodules in Portugal

Peter Perkins (UK) The generally accepted reason for the fame of Arouca is Princess Mafalda, born 1195, who was responsible for the convent becoming Cistercian. Here is an interesting story – she was beatified in 1793. However, I won’t go into that now, but it is well worth investigating. For this article, there are other reasons for its fame, at least among geologists. Arouca is 38km to the south east of Oporto, in northern Portugal, and gives its name to one of two geoparks in Portugal. In Arouca Geopark (Fig. 1), which has an area of 330km2 (just a little smaller than the Isle of Wight), there are two quite remarkable geological features, one palaeontological and the other concerning igneous petrology. Fig. 1. Map of Arouca Geopark. A geopark is an area of significant size that has a particular geological heritage, with a certain number of sites of special importance – scientific quality, rarity, aesthetic appeal and educational value. It must also have a sustainable strategy for development to be accepted as a member of the worldwide network of geoparks. There are 42 in Europe, in 16 countries. The other Portuguese Geopark is Naturtejo, through which the River Tagus flows. There are nine geoparks in the British Isles, for example, NW Highlands (Scotland), Copper Coast (Ireland), Fforest Fawr (Wales) and the English Riviera. The website, http://www.europeangeoparks.org, gives website addresses for all. The geology of Portugal is very complex. There are no strata younger than Triassic, except for Holocene deposits in … Read More

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Erratic rocks in fields and beaches of the Isle of Wight

 Stephen K Donovan (The Netherlands) The Isle of Wight is a marvellous place for the geologist on holiday, but there must be a suspicion that it has all been done before. When I first visited the island in 1999, my late wife Trina said that, of course, I would want to geologise at some point. She was surprised at my immediate and emphatic reply of ‘no’, until I explained that every square inch of the island was already ‘claimed’ by so many geologists and groups of geologists that I could not possibly get involved without starting a priority war. I was there to relax, not fight. Fig. 1. Outline map of the Isle of Wight, showing the positions of the principal settlements and villages mentioned in the text, and Sites 1-3. Key: CP = Chessell Pottery; EC = East Cowes; OH = Osborne House; 1-3 = collecting sites mentioned in the text. Today, I have a different approach. The family Donovan goes to the Isle for their summer holidays most years and I still go to the island to relax, not fight. But I am now working on a range of projects on the Island that are unlikely to impinge on other peoples’ research, while informing my own interests. These have included identifying borings in fossil wood from the Cretaceous greensands that have been misnamed since the nineteenth century (Donovan and Isted, 2014) and exploring closed railway lines using a geological field guide published a hundred years ago (Donovan, 2015). … Read More

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Mollusc diversity for palaeontologists

Dr Neale Monks (UK) While arthropods and roundworms exceed the phylum Mollusca in terms of species, molluscs hold their own when it comes to anatomical diversity. There may be well over a million species of arthropod, but crabs, spiders and bees are all obviously related, sharing the same multi-limbed body plan organised around a jointed exoskeleton. Molluscs are very different. Clams, snails and squid are all molluscs, but their anatomy, ecology and behaviour couldn’t be more different. What molluscs have in common Although incredibly diverse, molluscs do have features in common. These include: A fleshy foot used for locomotion.A visceral mass containing the internal organs.A mantle that secretes the shell.A toothy tongue, known as a radula, for scraping food into smaller pieces.A shell made from calcium carbonate.Not all molluscs have all of these features, but they each have at least some of them. So, while an octopus doesn’t have a shell, it does have a mantle and a radula, as well as a foot divided up into the eight arms that give it its name. From the perspective of the palaeontologist, the key thing about molluscs is that most have (or had) shells. These fossilise more readily than soft tissues or even bones, and that means that molluscs have a remarkably rich fossil record. Origins The earliest fossil molluscs are known from the very base of the Cambrian, the Tommotian, about 530mya. This period of time was marked by the appearance of several major animal groups alongside molluscs, including arthropods, … Read More

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Urban geology: Monumental geology

Stephen K Donovan (The Netherlands) My writings on urban geology are normally centred in the area around my home in Noord Holland, but sometimes I am lucky enough to travel. A personal wish that I have had since I was a teenager was to see and, if possible, board a dreadnought battleship. This whim was finally satisfied in March 2014, when I visited the last surviving dreadnought from World War I, the USN Texas, preserved at the San Jacinto Battleground State Historic Site, near Houston (Fig. 1A). What I had not realised was the battleship is interred adjacent to the site of the Battle of San Jacinto, where a rag-tag army of insurgents, following defeat at the Alamo and Goliad, decisively defeated the Mexican army in under 20 minutes in April 1836, thereby winning independence from Mexico for Texas. Fig. 1. Two breathtaking exhibits at the San Jacinto Battleground State Historic Site, near Houston, Texas. (A) The dreadnought battleship, USN Texas, commissioned in 1914 and a veteran of two world wars. (B) The San Jacinto Monument, built in 1936 from Cordova Cream Shellstone and the tallest memorial stone column. The San Jacinto Museum of History is in the base. The Battle of San Jacinto is commemorated by a towering monument (Fig. 1B), which is the tallest memorial stone column, about 175m, and some 4.5m taller than the much better known Washington Monument in Washington DC. The San Jacinto Monument is visible over a wide area of this flat coastal plane … Read More

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Dinocochlea (Part 1): The mysterious spiral of Hastings

Paul D Taylor and Consuelo Sendino (UK) Spiral structures in nature hold a particular fascination on account of their beautiful yet twisted symmetry. The logarithmic spiral coiling of ammonite shells and rams’ horns, the corkscrew helix of a plant tendril, and the planar spiral of a hurricane when viewed from space, all have an aesthetic appeal beyond that of simpler geometrical shapes. Fig. 1. The site in Hastings, as it appears, today where Dinocochlea was discovered during road construction in 1921. This is the first of a two part series on Dinocochlea. The second can be found at: Dinocochlea (Part 2): A possible solution to the mysterious spiral of Hastings. When huge spiral objects were unearthed during road construction in Hastings, almost one hundred years ago, it was not surprising that they attracted the immediate attention of geologists. To this day, the origin of these spirals from the Lower Cretaceous Wadhurst Clay is a puzzle. The story is as follows. History of the find In 1921, St Helens Road in Hastings (now the A2101) was extended westerly to meet up with Seddlescombe Road North (now the A21), thereby providing a bypass to Hastings town centre. Close to Old Roar Glen (a well-known local beauty spot) the workmen excavated a shallow cutting and came across some huge spiral structures lying horizontally in the rock. The engineer in charge of the roadworks immediately notified the Hastings Museum. Those specimens not already bagged as rockery stones by local inhabitants were sent to Dr … Read More

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Essential collectibles #5: Turritella gastropods

Dr Neale Monks (UK) Gastropods, or snails, are common fossils thanks to their strong, easily preserved external shells. Quite a few fossil gastropods are traded commercially, including members of the genus Turritella. This particular genus first appears in the fossil record during the mid Cretaceous and includes many species still alive today. If you know where to look, you can even find their shells washed up on beaches around the British Isles, often in considerable numbers, reflecting the success of these animals even today. So while fossil Knightia aren’t valued as rarities, they are extremely informative. The fine details preserved tell us about the anoxic conditions at the bottom of the lake and the fine sediments that quickly smothered the corpse. As herbivores of a sort, these fish occupied a position low down on the food chain meant they could exist in huge numbers, and by dint of that success they were able to support a whole range of predators that either fed directly on them, as with Diplomystus, or further up the food chain. Finally, the fact Knightia can only be found at certain horizons tells us something about the dynamic nature of giant lakes. They might seem unchanging on the human timescale, but on the geological timescale they do change, from being full of life at one point, then hypersaline and dead the next, perhaps even evaporating away completely some time later. The Turritella you’ll find in fossil shops are most commonly Tertiary species, such as the ubiquitous … Read More

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