Reports

My World of Fungus   6th Jan 2009

Rosalie Sincair-Smith has led the society on a couple of very interesting fungus forays at Chailey Common, so we were pleased to have her for a talk. She showed us some beautiful slides of many different fungi mainly taken by herself, and also explained to us the many uses of fungi in the natural world.

Fungi play an important part in re-cycling all waste matter, without them this world would become a gigantic dustbin, and would grind to a halt. Many have a special relationship with trees and dead wood, and work in partnership with them by supplying trace elements, like the fly agaric does with the silver birch.

Anti-biotics come from fungi, (penicillin), and quorn is derived from a fungus. Rosalie has experimented with making paper from a certain fungus, and showed us a drawing made using the ink made from the ink-cap family.

The largest fungus in the world is in America, and its underground root system is as big as a whole forest. Wounds can be staunched by puffing the spores of puff-balls on them as they are sterile, and Rosalie gave us many exaples of how useful fungi can be when in the wild, living off the land.

New species are being discovered all the time. She herself found a group of new fungi near Ditchling last year, which Kew identified as being the first seen in this country. How it got here no-one knows. Fungi are a fascinating subject, and Rosalie told us a great deal about them in a short space of time.

 

Joan Newman

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Reports

Recent Fossil Discoveries   20th January 2009

Peter Austen, an amateur geologist with a particular interest in Wealden plants gave us an interesting talk on recent fossil discoveries in the Weald. The talk was illustrated with excellent slides, some fine examples of fossils, which we could handle, and a display of press cuttings and other written material. Peter discussed many Wealden finds from the last 10-20 years and the importance of certain localities. Namely, in the lower Weald, the coast at Hastings, and, in the upper Weald, an inland brick quarry called Smokejacks Brickworks (just south of Walliswood, Surrey). He also mentioned finds at Cooden Beach, Bexhill.y found in lowest part of Ashdown Beds – a unit called the Fairlight Clays. Traces of the following fossilised plants have been found here in the last nine years: Bennettitales, an extremely rare Cycad cone, and Onychiopsis, a fern, which is the most abundant fossil plant in Weald. There is a plant bed just west of Fairlight Cove which contains three types of fern including Onychiopsis. This Bed also yielded other ferns, conifer cones and two types of bennettitales. Dinosaur (Iguanadon) footprints have been found in Lee Ness Sandstone, on the underside of sandstone ledges.

Rock-a-Nore

Caddis tubes, the home of caddis fly larvae, were found here in 19th century. In 1995 caddis tubes were discovered in material from a cliff fall. Peter visited the site and recovered hundreds of specimens from eight species. The Caddis tubes are made from Conchostracan shells which are small shrimp-like crustaceans with a carapace.

Cliff End looking West to Fairlight.

In 1996 – a bed of Quillworts, a form of clubmoss, was discovered in a 33 inch thick bed extending 400 metres along the cliff. These were the only in situ Quillworts in the UK. In Early 2001 Luke Booth found vertebra and ribs from an Iguanodon in a cliff fall following the rains of October 2000. He also recovered a turtle carapace. A Theropod trackway has been found with prints. Therapods were flesh-eating predatory dinosaurs. Hastings is also an important site for Early Cretaceous vertebrates. Although we often hear of dinosaurs from the Isle of Wight, there are actually more dinosaurs at Hastings. In addition there are fish, sharks, reptiles and mammals. Cliff End Bone Bed is rich in vertebrate material including the teeth of early mammals (rare). The first Cretaceous mammals to be described were found at Hastings

Brick Quarry

Over the last 10 years an extraordinary range of dinosaurs and reptile fossils have been found here, some new species and some families new to UK. The vertebrate specialist of the Natural History Museum, Angela Milner, has been taken aback by the number, quality and diversity of finds from the pit. Finds included a Polacanthus spike, vertebra and the only known toe bones of Polacanthus, an Ankylosaur tooth, Crocodile vertebra from a small Wealden crocodile (2 feet long) plus the top of skull, snout and bottom left jaw and teeth. Also found were Iguanodon toe phalanges, vertebrae and many Iguanodon teeth. Most of this material came from the main bed. Four metres above the main bone bed, Peter and his wife, Joyce, were on the hunt for plants. Plants in Northiam Sandstone were the usual Wealden variety of Onychiopsis, Conifers and Ferns with some seeds and beetles, but they also found Quillwort sporocarps in good preservation.

Cooden Beach

Peter has been visiting the beach from the early 2000’s prior to sea defence work. A number of interesting finds have been made here including a new species of crayfish and variety of insects including grasshoppers, cockroaches and bugs. A Brachiosaur toe bone was found at the beach, the Brachiosaur being one of very few large plant-eating Sauropods found on Mainland Britain.

This was an informative and inspiring talk. Peter made clear that there is much left to discover at these Wealden sites, so it will be fascinating to learn what new wonders are found in the next few years.

 

Wendy Brewer

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Reports

Spiders of the South Coast     13th October 2009

Our first speaker in our new venue was Ray Hale who came sporting his British Tarantula Society sweatshirt, explaining that he has been keeping spiders since he was a teenager. Clearly we expected great things of our first speaker and would have been hard-pressed to fit everyone in the old venue - and we were not disappointed, we were treated with a great talk on a fascinating subject.

There are some eight hundred and fifty species of spider, none is dangerous to humans. 99% of spiders have eight eyes though some have less. Spiders have different styles of web the most commonly seen in autumn of concentric circles are of the common garden spider, but there are also tunnels and hammock-shaped. As the circles are completed they are treated with a spot of glue, which spreads along the strand. The strength of the strands is ten times stronger than steel of the equivalent guage. Females will have two to three hundred young at a time (more for some species) but only ten per cent will survive. All spiders moult, adults once a year, juveniles more often. The male spiders are smaller and live shorter lives, their sole purpose in life being to mate, which they might only do once before being eaten by the female if they don't escape quickly enough. Spiders don't really hibernate, but will retreat into cracks for warmth.

Ray showed us pictures of a few of the spiders seen in Sussex; it seemed to me that many of the English names describe the insect or animal of which we are reminded.

Common garden spider - each night she will eat her own web as the thread itself is full of protein and will have also picked up creatures too small to bother with during the day.

False widow spider - all too easily confused with the real one! Nursery web spider - who carries her nursery round with her.

Woodlice spider - not found north of Watford as the south is a couple of degrees warmer, with jaws strong enough to break through the armour-plated woodlouse.

Wasp spider - an immigrant from Mediterranean (found on Lullington Heath) which, for some reason, only known to the spider herself, leaves a triangle out of the complete circle.

Zebra spider - is a protected species, is very small and aggressive. Ladybird spider - is a jumping spider, also protected, now a native, but an immigrant from warmer climes.

House spider - is the one you see running across your living room floor, a large spider with very long legs.

Mouse spider - is reputed to look like a mouse.

Crab spider - is very small, and lies on flowers, managing to change its colour to be similar to the flower.

Cellar spider - the daddy-long-legs of spiders.

Ray went on the speak of his particular interest, which is tarantulas and his worldwide travelling in search of new species. We look forward to his returning another time to show us his even more exotic photos. photos.

Colin Pritchard

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Reports

Eight-legged Hunters   17th November 2009

Although the Society had a recent talk on spiders, Dr Gerald Legg's presentation complemented and expanded on the knowledge we had acquired previously. We learned that if you are interested in spiders it is worth getting up early to watch one spinning a web. A web is very strong, very sticky and made of protein and therefore expensive of energy so that it is later eaten by the spider. The silk is not only used to make the web but can also be used as a net to catch prey or to tie up the female before mating! Dr Legg told us that he was once bitten by a False Widow Spider when cleaning the Booth Museum store cupboard!

Diana Swaysland

Further comments on Dr Legg's talk

My education started right at the beginning of Gerald’s fascinating talk. He wasn’t just talking about spiders; he wasn’t even talking about all arachnids – just those that hunt!

Gerald reminded us that, unlike insects which have 6 legs and 3 body segments and can fly, arachnids are invertebrates which have 8 legs and two body segments and can’t fly. Apparently, application of physics shows that, for animals of this size, 6 or 8 legs are the best option. Insects also have three sets of jaws whereas arachnids only have one. Arachnids include spiders, scorpions, ticks, mites and false scorpions. Harvestmen (or harvest spiders) are arachnids but not true spiders and do not hunt.

Spiders have two body segments – the first, a combined head and thorax, is very muscular and holds all the legs. The abdomen contains the digestive and reproductive organs and, at the very end of the body, structures for spinning silk. Gerald illustrated this with a photograph of Tegenaria gigantea (a relatively uncommon spider related to the common house spider found in older houses with cellars) with the legs stretched out to the size of a dessert plate.

All spiders are hunters. Some spiders wander around looking for food and some, such as wolf spiders, hunt at night. Spiders have good sight with stereoscopic vision. Others wait for food to come to them. Crab spiders hide in flower heads. The raft spider sits on vegetation on the water and detects movement – it can take on a 3” stickleback. Some spiders inject neurotoxin, others dissolve flesh – in the tropics causing wounds the size of dinner plates.

One of the key characteristics of spiders is their ability to spin silk (although some insects such as the silk moth also spin silk). Silk is incredibly strong and elastic and all spiders produce silk with the same chemical structure. It has been used to drop tanks from helicopters. Silk has a variety of uses. Some spiders spin silk for webs. Others use it for restraining females.

Gerald talked about a variety of webs. The bolus spider puts a blob on the end of silk and throws it to capture its prey. One makes a triangular web and makes itself one of the 3 links – it lets go when the prey arrives and it shoots forward like a net.

Chris Brewer

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Reports

Human Evolution   8th December 2009

Professor Reynolds began by explaining Darwin's theory of evolution by natural selection and went on to describe the primate family tree, of which humans are the most advanced, and as deduced from available fossil remains.

He said that the primate ancestry can be traced back to a Prosimian, Smilodectes, which was a kind of lemur living in Africa in the Eocene Epoch, some 55 my a (million years ago). These evolved into monkeys around 25mya, and the progenitor of apes, Proconsul (lacking a tail) appeared around 15mya. The hominid branch of the ape family began evolving from the early apes around 5mya and the first identifiable one, Ardophithecus Ramidus had evolved by 4.4mya

Climate changes resulted in savannah type landscapes in Africa suiting hominid development and in particular bipedalism. By 3.5mya Australopithecus Afarensis had appeared, exemplified by the fossil skeleton known as Lucy, found in the Afar region of Ethiopia. Evidence at the Lucy site showed that her type used sharp-edged broken stones as tools but had not yet learned to make them. The Australopithecines (Southern Ape-men) evolved into two distinct forms: a robust, vegetarian form (A. Robustus), which soon died out, and a gracile, mixed diet form (A. Africanus), which was successful. Homo Habilis (Handy Man) had evolved from the gracile form by 2.5mya, with a larger brain size of 750cc, able to fashion stone tools.

By 1.5mya a tall biped, H. Erectus, had evolved, with a 1 OOOcc brain, and so successful that they began migrating out of N.E. Africa, via coastal routes to southern Europe and into Asia, reaching as far as China and Java. At around this time H. Ergaster evolved in N.E. Africa, some died out there while others migrated to the south and appeared to be successful. H. Heidelbergensis evolved from H. Erectus in Europe, who in the interglacial periods around 700,OOOya and 300,OOOya extended their range as far as Britain. For example, Boxgrove man (a single tibia bone dated at 400,OOOya) and Swanscombe man (partial skull remains of the same period) were both of H.H. Type. After the "Boxgrove" warm period, the Great Ice Age occurred and H. Neanderthalis evolved in Europe, more adapted to the cold climate.

At about 200,000ya, H. Sapiens with a 1400cc brain appeared in southern Africa, migrated northwards, reaching Europe and Asia around 50,000ya, and replaced the Neanderthals who died out at about this time. Professor Reynolds also explained about the Piltdown Hoax.

Professor Reynolds had a number of exhibits to illustrate the subject including skull casts of Procaonsul, A. Australopithecus, H. Erectus, the skull of a modern chimpanzee and a superb stone hand-axe. He recommended reading "The Inheritors" by William Golding, and any of the "Aylay" books by Jean Auel.

It was a stimulating talk on a subject well worth further study. I can also recommend the book "Homo Britannicus" by Chris Stringer.

Roger Hitchin

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Reports
page updated 30th June 2012