Encrinus liliiformis – a crinoid from the Triassic that made a career for itself: Germany’s fossil of the year, 2019

Jens Lehmann (Germany) Despite their common name ‘sea lilies’, crinoids are animals but not plants, although they look like a flower (Fig. 1). They are related to the sea urchins, sea cucumbers and starfish, groups that are unified as echinoderms (see, for example, Broadhead and Waters, 1980). Crinoids consist of a “root”, a stem built of many disc-shaped elements (columnals) and a crown. Fig. 1. A crown of the famous crinoid, Encrinus liliiformis, from a Muschelkalk quarry in Northern Germany. The fossil shows a slightly opened crown, with a number of arms besides each other. The name “sea lily rock” is often associated with the basal plates of fossilised crowns that resemble a lily flower and were collected as “Lilienstein” (“lily rock”) by gentlemen collectors in Central Europe, particularly in the nineteenth century (Fig. 2). In fact, crinoids were encountered for many hundred years and thus were already known by the famous Swiss and German scientists (respectively), Conrad Gessner and Georgius Agricola, in the sixteenth century. However, these early geoscientists only found the fossils, since living crinoids can only be found in the deep sea and were not known by the scientific community before the eighteenth century. This is the reason why the isolated stem elements called columnals occur in millions of specimens in the German Muschelkalk (Middle Triassic) were mystically called “Boniface pennies” or “Witch money”, before they were recognised as parts of crinoids. Fig. 2: Even details of Germany’s “Fossil of the Year 2019” are beautiful, like these … Read More

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Caught between two mass extinctions: The rise and fall of Dicroidium

Chris Mays and Stephen McLoughlin (Sweden) In the aftermath of Earth’s greatest biotic crisis 251.9 million years ago – the end-Permian mass extinction – a group of plants arose that would come to dominate the flora of the Southern Hemisphere. Recovery of the vegetation from the end-Permian crisis was slow; but steadily, one group of seed plants, typified by the leaf fossil Dicroidium, began to diversify and fill the dominant canopy-plant niches left vacant by the demise of the Permian glossopterid forests (Fielding et al., 2019). Eventually, Dicroidium re-established a rich peat-forming vegetation across Gondwana through the Late Triassic, dominating the flora between 30°S and the South Pole (Kustatscher et al., 2018). Indeed, few fossil plant assemblages of this age can be found in Gondwana that do not contain this plant. The importance of Dicroidium is not just its role in showing biogeographic and tectonic linkages between southern lands or its value in determining the age of continental strata. Dicroidium and its associated plant groups were so successful that they were major contributors to the development of thick coal seams in the Late Triassic that are now mined to produce electricity. Although Dicroidium is generally envisaged as a plant of cool temperate climates, the very first fossils that might belong to this group are from the Permian-Triassic transition of Jordan, located near the palaeoequator (Blomenkemper et al., 2018). Nevertheless, the distribution of Dicroidium soon shifted to high southern latitudes in the Early Triassic and they overwhelmingly dominated the southern vegetation … Read More

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Pistol shrimps: How to recognise them in the fossil record

Matúš Hyžný (Slovakia), Andreas Kroh (Austria), Alexander Ziegler (Germany) and John WM Jagt (The Netherlands) Alpheid shrimps, colloquially referred to as “pistol shrimps”, exhibit a remarkable anatomical adaptation. These tiny marine crustaceans use their enlarged and highly modified claw to ‘shoot’ at their prey – hence their name. It is astonishing that the snapping claw evolved at least 30 million years ago. How do we know that? Because the fossils tell us. Fig. 1. Habitus (body form) of alpheid snapping shrimps, exemplified by the extant species Alpheus thomasi from the Caribbean Sea. (Photo: Arthur Anker.) The famous snapping claw Alpheid pistol shrimps represent a super-diverse group of benthic marine crustaceans (that is, living on the bottom of the sea, including the sediment surface and some sub-surface layers). There are more than 600 living species, nearly half of which belong to the genus Alpheus. Its representatives possess a snapping claw, a multifunctional tool used for various types of behaviour such as aggression, warning or defence, as well as for hunting prey. Although snapping claws evolved independently several times within various decapod crustaceans, only in pistol shrimps did this organ attain true perfection. Fig. 2. Pistol shrimps ‘shoot’ with an enlarged, modified claw. (Photo: Arthur Anker.) The process of snapping involves a cracking sound reaching up to 210 decibels, one of the loudest produced by any animal. This noise originates from the collapse of a cavitation bubble in front of the claw, which, in addition, is accompanied by a short flash of … Read More

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Making of a monster: ‘Cannibal the Animal’

Mats E Eriksson (Sweden) A hellish monstrosity of an animal – like a beastly entity taken straight out of your worst nightmare – has come to sculptural life. And it has Death Metal, primordial life and Alex Webster written all over it. Fig. 1. The monster sculpture in progress, with its ‘daddy’ model maker Esben Horn, who also functions as a scale (Esben Horn is 1.85m tall). At this stage, the worm’s body has been roughly sculptured out of Styrofoam and, alongside, the huge jaws still await several adjustments. (Photo: Mats E Eriksson.) Last year, a new gigantic fossil polychaete worm – Websteroprion armstrongi – was discovered and unveiled to the world (Eriksson et al. 2017). (I discuss this in my article: Worm monstrosity: A giant extinct worm.) The creature is an ancestor to the now-living, marine ‘Bobbit’ worms – ambush predators that hunt in stealth mode for octopuses and fish. The fossil species was discovered in 400 million years old rocks from the Devonian Period in Canada and was named in honour of mighty bass giant, Alex Webster, of Cannibal Corpse, Blotted Science and Conquering Dystopia. Now, this primordial animal has come to ‘life’ by the skilled hands of prehistoric sculpture artist extraordinaire Esben Horn, at his company 10 Tons (see Eriksson, 2014) in Copenhagen, Denmark, and assisted by me, who was lead author of the scientific study presenting the species. Since I reported on the discovery of W. armstrongi in Issue 50 of Deposits (Worm monstrosity – a … Read More

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Wealden insects: An artist’s update (Part 4)

Biddy and Ed Jarzembowski (UK) An ‘artist’s impression’ of Wealden insects, inspired by the original work of Neil Watson, appeared in a three-part mini-series in Deposits issues 47 to 49. Since then, the discovery of a number of species new to science (belonging to diverse groups) has meant that an update was needed. Here are some completely new watercolours by Biddy, including the first true bug (heteropteran) from the Wealden, and the first Wealden earwig (dermapteran). Insects are arthropods and an accompanying Wealden crustacean is added this time. Photographs of actual fossils found in the Weald Clay Formation of Lower Cretaceous (Hauterivian and Barremian) age are provided too. We are indebted to Fred Clouter, Terry Keenan, Tony Mitchell and Pete Austen (UK) for help with these images. As before, Ed has supplied some explanatory notes to accompany the pictures, with more on the way. We have incorporated some new ideas on established species, such as different interpretations of the fossil lifestyle in the case of the ‘moss’ bug. Wealden insects are often disarticulated (due to transport in water). Where intact relatives are known from other contemporary deposits (especially Asia and Spain), these have been referred to, as well as recent representatives. While we can now recognise the commoner insect groups from the late age of the dinosaurs, continuing fieldwork shows that others remain to be unearthed. The artist’s job is ongoing, like that of the specialist and collector. We shall continue to periodically share the finds with you as a … Read More

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Rudists: A fossil story

Jack Shimon (USA) This article is adapted from a presentation given at the Denver Gem Show, September 17, 2016 by me, Jack Shimon. When I was six and a half years old, my Grandpa took me fossil hunting in central Texas. We went to a Carboniferous Limestone quarry that he had visited earlier and was given permission to enter and collect from. This was one of my first fossil hunting trips and I really enjoyed it. The ancient reef we went to (now a quarry) had huge boulders of limestone and tube-like things in it we later to be found to be rudist bivalves. This article is all about these finds and the efforts we went to, to find out what they were. Fig 1. The author at the quarry. (Photo credit: Mike Hursey.) Fig. 2. This Google satellite image shows the reef we collected from. Two of the three lobes have been excavated for limestone. You can also see smaller pinnacle reefs marked with the short arrows. All of the reefs rise above the flat Texas landscape. (Permission from Google.com: ‘Special Use Guidelines’.) Fossils We spent a lot of time at the quarry observing the massive specimens onsite and then collected some smaller pieces to bring home and look at closer. A simple way of thinking about fossils is to consider them either as a cast or a mould. A mould is formed when an object is placed into a soft substrate and then decomposes or is washed away … Read More

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Bryozoans in the English Chalk

Dr Paul D Taylor (UK) We are very fortunate in Britain to host one of the most remarkable deposits in the entire geological record, the Chalk. The Late Cretaceous Chalk (with a capital ‘C’) is an extremely pure limestone, famous for the White Cliffs of Dover and responsible for the landscape of rolling hills and dry valleys, forming the ‘downs’ and ‘wolds’ that stretch through England from Devon in the southwest, to Yorkshire in the northeast. The economic importance of the Chalk to the early human inhabitants of Britain was enormous because the flints contained within it could be fashioned into axe heads and hard cutting tools. Why is the Chalk so special geologically? It is a rare example of a pelagic sediment – an open ocean sediment – that was deposited over the continental shelf. This occurred at a time when global sea-level was high and the supply of terrigenous clastic sediment into the sea was minimal. The Chalk is an oceanic ooze composed mainly of the disaggregated plates – coccoliths – of coccolithophores, planktonic microalgae with exquisitely engineered skeletons of calcite. Unfathomable numbers of coccolithophores sank to the seabed over a period of some 35 million years to produce the thick accumulation of Chalk that today extends over northern Europe and into western Asia. The Chalk is a favourite hunting ground for fossil collectors, yielding beautifully preserved specimens, especially of echinoids. But closer inspection of the Chalk shows that the dominant macrofossils are often bryozoans. These colony-forming invertebrates … Read More

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Triassic beasts and where to find them

Sue Beardmore (UK) Located amid the scenic Southern Alps, on the Swiss-Italian border, is Monte San Giorgio, a mountain that rose up like many across Central Europe as a result of continental collision between Africa and Europe during the Alpine Orogeny. It is not particularly big or distinct by alpine standards but it is special, a status emphasised by the designation of its slopes as a UNESCO World Heritage site initially in 2003 for the Swiss part with the neighbouring Italian area added in 2010. To begin, the rocks outcropping on the mountain form an almost complete stratigraphic sequence from the Permian through to the Jurassic (Fig. 1), not only an extended interval of time but an important one around the massive Permo-Triassic extinction. The same rocks provide a context for the equally important Middle Triassic vertebrate, invertebrate and plant fossils, now numbering more than 20,000, that have been found at the locality over the last 170 years. Fig. 1. A stratigraphic section of the rocks at Monte San Giorgio. © Commissione Scientifica Transnazionale Monte San Giorgio, 2014. In particular, it is the diversity, relative abundance and excellent preservation of the vertebrate fossils that has thrown the locality into the spotlight. These occur in six main fossiliferous horizons deposited in a shallow marine basin, the Monte San Giorgio Basin, one of many depressions on a carbonate platform between the Eurasian continent to the north and west, and the open waters of the vast Tethys Ocean to the south and east. … Read More

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Worm monstrosity: A giant extinct worm

Mats E Eriksson (Sweden) In a new study published in Scientific Reports (Earth’s oldest ‘Bobbit worm’ – gigantism in a Devonian eunicidan polychaete) by Luke A Parry of Bristol University in the UK, David M Rudkin of the Royal Ontario Museum in Canada and me (Mats E Eriksson of Lund University in Sweden), an extraordinary new species of polychaetes (that is, bristle worms – the marine relatives of earthworms and leeches) is described. The new species, Websteroprion armstrongi, is unique among fossil worms and possessed the largest jaws recorded from all of earth history, reaching over one centimetre in length and thus easily visible to the naked eye. Typically, such fossil jaws are only a few millimetres in size and must be studied using microscopes. Despite being only knows from the jaws, comparison of Websteroprion armstrongi with living species suggests that this animal achieved a body length in excess of a metre. This is comparable to that of ‘giant eunicid’ species, colloquially referred to as ‘Bobbit worms’, a name that is bizarrely enough derived from the infamous story of eye-watering amateur surgery involving Lorena and John Wayne Bobbitt. Living ‘Bobbit worms’ are fearsome and opportunistic ambush predators, using their powerful jaws to capture prey, such as fish and cephalopods (squids and octopuses), and drag them into their burrows. Fig. 1. A photograph showing the holotype of Websteroprion armstrongi. (Photo by Luke Parry.) Gigantism in animals is an alluring and ecologically important trait, usually associated with advantages and competitive dominance. It … Read More

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