Golden Wonder! Rare fossil trilobite preserved in stunning detail Lucy McCobb, 2 August 2013 A tiny Triarthrus eatoni specimen lies next to the bigger one. Trilobites of various ages were fossilized together and must have lived in the same place. Only larvae are missing. Trilobites are common in the rocks in Wales, but this rare specimen differs from others in our collection. Preserved beneath the carapace are the legs and on the head a pair of delicate antennae ('feelers'). These features stand out vividly in gold against a black shale background. Such exceptional fossils give us great insights into how trilobites moved, fed and sensed the world around them. All trilobites had legs and antennae when they were alive, but these were quite soft and usually rotted away before they could be fossilized. Most trilobite fossils are just parts of the hard exoskeleton or carapace and tell us little about the softer parts of the body. Why is the trilobite golden? The golden colour is because the animal has been fossilized in pyrite, also known as iron pyrites or Fool's Gold. Fossilization of soft body parts in pyrite is very rare, and is only known from a couple of places in the world. This particular fossil comes from rocks of Ordovician age (approx. 455 million years ago) from New York State in the USA. Soft-bodied fossils preserved in pyrite are also found in the much younger Hunsrück Slate in Germany, of early Devonian age (approx. 390 million years ago). Pyrite is an iron sulphide mineral (FeS2), and it can form where there are low oxygen levels and lots of iron. The trilobites were probably swept up by an underwater avalanche and buried in deep sea mud. The mud would have been rich in sulphates and dissolved iron, but low in oxygen. Sulphate-reducing bacteria would have helped decay the trilobites, releasing sulphides. The sulphides combined with the dissolved iron to form pyrite, which replaced or coated the trilobite tissues as they decayed. The Museum's golden fossil from Martin Quarry, New York State. Larger trilobite approx. 3 cm long Beecher's Trilobite Bed Pyritized trilobites have been known from the famous Beecher's Trilobite Bed in New York State for over a century. The bed was discovered by amateur fossil collector William S. Valiant in 1892, but is named after Charles Emerson Beecher, an academic from Yale University to whom Valiant showed his amazing trilobite finds. Beecher leased the land between 1893 and 1895, and quarried out as many fossils as he could, until he thought there was nothing left to be found. He wrote many scientific papers about the trilobites until his untimely death in 1904. The trilobites were found in just one thin (4 cm) layer of rock, laid down around 455 million years ago, during the Ordovician period. C.E. Beecher's 1893 reconstruction of Triarthrus eatoni based on fossils from his Trilobite Bed. The legs have two branches, an inner walking leg and an outer gill with fine filaments. The Trilobite Bed was rediscovered in 1984 and since then, more beds containing golden trilobites have been found in New York State. In 2004, an amateur collector started searching about 50 miles away, and eventually found a rock layer of the same age containing trilobites. Our specimen comes from this new quarry, now known as Martin Quarry after its finder. Many important fossils have been found in Martin Quarry and studied by Professor Derek Briggs of the Yale Peabody Museum, and his colleagues. Growing Up Our specimen (Triarthrus eatoni) has a second, tiny trilobite next to the larger one. Trilobites grew from larva to adult by going through a series of moults. As they got older, they regularly moulted off their old exoskeleton to grow bigger. Many different sizes of Triarthrus have been found in the Trilobite Bed, but none of its earliest larval stage. Trilobites of various ages clearly lived together, but the larvae must have lived somewhere else. They may have floated around as plankton in the water column, while larger juveniles and adults lived on the sea bed.
No blog days Graham Oliver, 2 August 2013 This happens on research cruises, some vital piece of gear is not working and as usual it has something to do with electronics on the remote camera array CAMPOD. So we are still in Tromsø! [1]Talking of small cogs [2] in big wheels there was also a problem with one of the winches yesterday, but that is sorted.A reminder that my ship [3] the "GO Sars" was named after the very famous Norwegian marine biologist who specialised in crustacean and molluscs, his books are still used to this day and are in the Museum's zoology library.Also in Tromsø are two other research ships the older Norwegian "Hakon Moseby" [4] named after a Norwegian oceanographer and meteorologist and the massive German "Maria S Merian" [5] . This ship was named after Maria Sibylla Merian (1647-1717) a naturalist and illustrator [6 & 7] . See http://en.wikipedia.org/wiki/Maria_Sybilla_Merian for an account of this gifted lady pioneer who went to Surinam.The sun is still shining in Tromsø and we have been informed that we sail around 01.00hrs.Its now 07.30, breakfast time and we are leaving a cloudy Norway behind [8]. If you want to see where we are minute by minute you can see our position on the marinetraffic websiteWe should be at our first sampling station in 22hrs.
Day 1: Waiting for the ship in Tromsø; Two museums in one day – too much? Graham Oliver, 31 July 2013 Tromsø University Museum [1] was established in the 1870s, it covers both regional natural history and culture. Small zoology and geology galleries explore northern Norway including an artificial aurora borealis machine (terella) [2]. Zoology is represented by a series of dioramas with a rather familiar sea-bird cliff [3]. There is content on human influences on nature including a view of what the local landscape (including flamingos and parakeets) might look like following climate change [4].Geology has more content, not surprising with the rugged exposed landscapes up here. I thought the section on building stones was well done with a montage of polished stones [5] and a display of local slates [6]. They are very proud of their 10 metre ichthyosaur from Svalbard. No photo here as the reflection in the glass protection is impossible to resolve. Curator Elsebeth Thomsen tells me that the whole gallery will be refurbished soon with walk-over glass for the ichthyosaur.Much more challenging was 'Metopa' in the Polarmuseet [7]. This exhibition [8] shows the research work of one of my sea-going colleagues Anne Helene Tanberg seen here on the left at the opening [9]. Metopa is the Latin name of the genus of amphipods that Anne Helene has been studying for a number of years now. The most familiar of the amphipods are the sandhoppers we find on our beaches but Metopa are small cold-water species. In this 28 panel show we are introduced to the morphology, classification and ecology of amphipods and how Anne Helene collects and studies them. For you museologists out there this is a challenging project as the content may not be seen as being for family audience. But Anne Helene has had positive feedback from visitors and school groups including kindergarten. The panels are attractive with excellent photographs of living amphipods [10] as well as reproductions [11] from the classic work of 1894 by the Norwegian Georg Ossian Sars, to whom the research ship has been dedicated. I have included some images of the texts [12, 13, 14], so you can debate among yourselves on the style and content. The panels are supported by a case filled with part of her collection and an epibenthic sledge [15] used to collect amphipods from the ocean floor. Anne Helene has also had workshop days when she has worked in the gallery [16].Would this work in Cardiff? I don't know. Here people live much closer to nature, most children will have spent some time messing on the shore and the sea is an intimate part of most peoples' lives.
Francis Crawshay's Workers 26 July 2013 The sixteen men in these little portraits all worked for Francis Crawshay (1811-1878), a reluctant industrialist, who maintained unusually close personal relationships with his employees. In the mid-1830s, Francis was in charge of the Hirwaun Ironworks, acquired by his father, the great ironmaster William Crawshay II, in 1819, and of the family’s recently enlarged tinplate works at Treforest, near Pontypridd. The group includes both skilled and unskilled workers as well as managers, and all are depicted as standing figures in a landscape, in working clothes and with the tools of their trade. Although the wealthy sometimes commissioned portraits of their domestic servants, no other such images of industrial workers are known. The pictures are believed to be by William Jones Chapman (c.1808-after 1871), a travelling portrait and sporting painter who worked mostly in Wales and the border counties. The group passed by descent in the Crawshay family, and may originally have been even larger. Attributed to William Jones Chapman (c.1808-after 1871), sixteen portraits of employees of Francis Crawshay (1811-1878) at the Hirwaun Iron Works and the Treforest Tinplate works, about 1835-40. Given by Miss Sylvia Crawshay, 2012 Francis Crawshay's Workers William James, Roller, Forest Unknown Man Thos. Francis, Quarryman, Forest Thos Euston, Lodge Keeper, Hirwaun Thomas Kirkhouse, Hirwaun Rees Davies, Mechanic, Hirwaun Llewellyn Jenkins, Foreman Carpenter, Hirwaun John Richards (John Cwmbran) John Llewellyn, Foreman Smith, Forest John Davies, Tin Mills Manager John Bryant, Mine Agent, Hirwaun Evan Bryant, Agent, Hirwaun David Williams, Carpenter, Forest David Lewis, Storekeeper, Hirwaun David Davies, Fineries, Hirwaun David Davies, Cinder Filler, Hirwaun
week one of summer 2013 Grace Todd, 26 July 2013 It hasn't been our busiest week in terms of numbers but I can't blame our visitors for wanting to make the most of the lovely weather. Not being as frantic as we often are has meant that families have been able to spend a long time engaging with some lovely handling objects and learnt a lot about Bronze Age design. I have been tweeting pictures of people's creations every day, but here are two photos from the week. Tomorrow we change activities to look at and make our own Bronze Age shields.Also I wanted to mention a very exciting family treasure hunt we are running throughout the museum during the school holidays. Cardiff Bay Rotary Club have kindly donated some book tokens as prizes. Come and see us for more information.Have a nice weekend
