Seed to Feed Me: January 2014

Monday, 27 January 2014

FOSSIL PLANTS

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Fossil plants tell us a story about the vegetation that existed millions of years ago, and how plant species have evolved over those years.

Plant tissues are very delicate, especially the leaves and flowers. Because many plants live on land there are few fossil remains as most fossils are formed in sedimentary rocks. Plants on land are exposed to much weathering, even if they are covered with sediment. Tissues break up as they die and roots and stems can be preserved in different locations.

Plant fossils found are often black carbon films left on bedding surfaces. On occasion three dimensional fossils are found. Pollen grains fossilise very well, and have enabled scientists to recognise many plant species.

Plant fossils enable us to reconstruct the environment in which they lived. Plants are very specialised and can often indicate the climate in which they lived. Fossil records show that some plant species disappeared with changes in climate.

The earliest plant fossils to be discovered were algae on rocks (stromatolites) from the Cambrian period 500 million years ago. These showed an important stage of the earths development when the first oxygen was released into the primitive atmosphere.

Simple vascular plants evolved in the Silurian period over 400 million years ago. During the Devonian period plants became commonly green. During the carboniferous period 300 -350 million years ago great forests were formed. Many plants that we are familiar with today developed 5 - 20 million years ago during the Cenozoic era.

Flowers developed quite late during late Mesozoic period 200 million years ago. They enabled plants to cross pollinate which was significant as it led to genetic diversity. Nectar and pollen from flowers also provide food for insects, which quickly evolved after.

A true living fossil is the Williamsonia pine, which existed in the Jurrasic period. It was thought to be extinct but then living plants were discovered in recent times. Now the pine has been propagated and can be bought readily in garden centres as a living fossil.

For related articles click onto:
Acid rain and its effect on wildlife
Archaeopteryx
Can starfish grow back their arms?
Caring for the coral reefs
Causes of acid rain
Coral reefs and the greenhouse effect
Conserving fossil fuels
Energy saving light bulbs
Fossil plants
Fossils: Venericardia
Fossils: Turritella
Famous fossils
Fossil Fuels
Fossil fuels: Alternative sources of energy
Fossil hunting at Bracklesham Bay
How are fossils formed?
How many seas are there in the world?
Keystone species
Star Starfish
What is a cuttlefish?
What is a sea anemone?
What is a starfish?
What is a loofah?
What is the greenhouse effect?
What is a sea sponge?
What is a sea cucumber?
What is the difference between an asteroid and a comet?
What is the difference between a rock and a stone?
What is the difference between hibernation and sleep?
What is the difference between a fog and a mist?
What is a fossil?
What is acid rain?
What is fracking?
What is global warming?
What is the greenhouse effect?
What is the Gulf Stream?
Where are fossils found?

Friday, 17 January 2014

WHERE ARE FOSSILS FOUND?

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Fossils are not found in every part of the world, and appear only in certain areas. This is because fossils are preserved in some rocks, but not others.

Rocks can be formed in three ways. Rocks formed by from lava on the earths surface or from magmas deep underground are called Igneous rocks. Secondly, Metamorphic rocks are formed when rocks have undergone profound changes due to pressure and heat. The last type of rock found on Earth are sedimentary rocks which form on the earths crust.

Fossils are much more likely to be found in sedimentary rocks. This is because of the way they are deposited as mud, sand or other material. Each stratum represents the deposition of sediment on the seabed, lake, river or land surface. This leads to stratification, which can be clearly distinguished as different layers, of which undoubtedly the KT boundary is the most famous and can be seen around the world.

Fossils may sometimes be found in other types of rocks as volcanic ash and dust may settle in water and preserve marine animals. Metamorphic rocks such as slate may contain fossils, although they tend to be distorted.

Sedimentary rocks

Sedimentary rocks are classified into there groups; detritial, organic and chemically formed.

Detrital or fragmentary sediments include sandstones, mudstones, shales, conglomerates and breccias. They are made from materials such as sand grains or mud particles that have come from weathered pre-formed rocks and then have been carried and deposited by the sea or rivers. Fossils found within these fine grained rocks are likely to be preserved in great detail. Marine shales and clays are rich in mollusc and arthropod fossils, whilst land formed sandstones and shales are likely to preserve vertebrates and plant fossils.

Organic sedimentary rocks are formed from organic plant or animal material. They tend to be pale in colour and porous. Coral limestones are formed from sediments from coral reefs, whilst crinoidal limestone is formed from seabed banks of crinoid stems. Lime stones are rich in fossils such as ammonites and gastropods.

Some sedimentary rocks are formed by a chemical process. These include Oolitic limestone which is formed from small oolith grains. They are composed of layers of calcite precipitated around a minute shell fragment or sand grain. These rocks are often found in shallow marine areas and can be rich in fossils of echinoderms, brachiopods, molluscs and corals.

For related articles click onto:
Acid rain and its effect on wildlife
Archaeopteryx
Can starfish grow back their arms?
Caring for the coral reefs
Causes of acid rain
Coral reefs and the greenhouse effect
Conserving fossil fuels
Energy saving light bulbs
Fossil plants
Fossils: Venericardia
Fossils: Turritella
Famous fossils
Fossil Fuels
Fossil fuels: Alternative sources of energy
Fossil hunting at Bracklesham Bay
How are fossils formed?
How many seas are there in the world?
Keystone species
Star Starfish
What is a cuttlefish?
What is a sea anemone?
What is a starfish?
What is a loofah?
What is the greenhouse effect?
What is a sea sponge?
What is a sea cucumber?
What is the difference between a rock and a stone?
What is the difference between an asteroid and a comet?
What is the difference between hibernation and sleep?
What is the difference between a fog and a mist?
What is a fossil?
What is acid rain?
What is fracking?
What is the greenhouse effect?
What is the Gulf Stream?
Where are fossils found?

Monday, 13 January 2014

FOSSILS: VENERICARDIA

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I recently visited Bracklesham bay, West Sussex with the kids to do a spot of fossil hunting. Its an ideal spot for the family as its so flat we could take the pram along with us too. We weren't expecting to find many fossils but we were surprised by the amount that are just washed up in the sand.

One of the most numerous fossils on the beach was the fossilised shell of Venericadia, a marine mollusc that lived 44 million years ago. These fossils are found in the Palaeocene and Eocene strata in Europe, America and Africa.

Venericardia lived in shallow seas on seas beds of sand and silt. This bivalve had a wide, ribbed shell that could grow up to 150 mm. The shell has deep ribs running back to front which are intersected buy shallow groves, which make it look very shell like and similar to modern day clams. In fact these fossils do look incredibly new that is is only the brown colouration and weight that makes it stand out amongst the shells.

Venericardia burrowed into the ground posterior end uppermost and could withstand turbulent waters.There are large hinge teeth on the inside of the molluscs shell which gave them immense strength and protection amongst predators and desiccation.

Kingdom:	Animalia
Phylum:	Mollusca
Class:	Bivalvia
Order:	Carditoida
Superfamily:	Carditoidea
Family:	Carditidae
Subfamily:	Venericardiinae
Genus:	Venericardia

FOSSILS: TURRITELLA

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These fossils were also present at Bracklesham bay, West Sussex on our recent fossil hunting trip. They remind me of miniature unicorn horns as they look so delicate and beautiful. They are in fact sea snails (gastropods) that lived during the Cretaceous period to recent age.

Turritella have a very distinctive corkscrew shell. This long, slender shell is made of many small whorls which overlap. These gastropods lived around sedimentary rocks in shallow water. They would have burrowed vertically into the sand with its corkscrew shell with the aperture of the shell just under the sand.

Fossils can be found up to 100 mm long and can be found world wide.

Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
Subclass:	Caenogastropoda
Order:	Sorbeoconcha
Superfamily:	Cerithioidea
Family:	Turritellidae
Subfamily:	Turritellinae
Genus:	Turritella

Thursday, 9 January 2014

FAMOUS FOSSILS

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Throughout history there have been some fossil finds that have been so significant that they have changed scientific and public opinion almost overnight. The significance of these fossils is immense and they have had a profound effect on palaeontology. It seems incredible to me that beyond 200 years ago the existence of dinosaurs was not acknowledged.

There have been many dinosaur fossils discovered but some of the most significant finds are detailed below.

Megalosaurus
In 1676 the partial femur of a Megalosaurus was unearthed in England. Nothing like this had been discovered before, and there was no comprehension of a time before man when giant reptiles walked the earth. It was declared at the time by a professor at Oxford University that this huge leg bone was from a human giant. Only in 1844 was this bone was conclusively identified as a dinosaur by the famous palaeontologist Richard Owen.

Mosasarus
In 1764 the skeleton of Mosasaurus was discovered. This was the first fossil to be identified by naturalist Georges Cuvier as an extinct species. Until then the strange bones that had been dug up along lakes and river beds had not been identified as belonging to creatures that had lived and died millions of years before human had existed. In a religious society creationism was widely believed, and so the theory of evolution and existence of such creatures was not yet in existence.

Iguandon
In 1820 the fossil of Iguanodan was discovered, and it immediately prompted public debate as to whether ancient reptiles ever existed. Key scientists at the time dismissed the bones as belonging to a fish or rhinoceros, but the argument was slowly won by Richard Owen and the significance of this find was recognised. However, the first impressions of the dinosaur were incorrect and famously the thumb spike was misinterpreted as a nose horn.

Hadrosaurus
In 1858 the first complete dinosaur skeleton (Hadrosaurus) was discovered in North America by Foulke.

Archaeopteryx
This bird like dinosaur was discovered in Germany in 1860. This feathered dinosaur appeared to show the missing link between birds and reptiles. It had feathers like a birds, but lacked the hollow bones of a bird. It had a bony jaw with teeth, clawed hands and the tail of a reptile. Charles Darwin published his book 'The Origin of Species' in 1860 which coincided with this spectacular find.

Diplodocus
In 1877 the first skeleton of a diplodicus was discovered in North America. This giant sauropod was by far the biggest dinosaur discovered to date.1877 was a good year for finding dinosaur fossils apparently as Stegosaurus and Brontosaurus also discovered this year.

Stegosaurus
1877 was the year that Stegosaurus was first discovered.

Brontosaurus
Marsh also discovered the first Brontosaurus (Apatosaurus) in 1877. This ankylosaurid dinosaur is characterised by its armoured backs or shells, as well as tail spikes.

Iguanodon herd
Palaeontologists uncovered a herd of Iguanodon discovered by two coal miners in a coal mine in Belgium in 1878. At least 38 Iguanodon individuals were uncovered, most of which were adults. The skeletons were some of the first complete dinosaur skeletons known and showed the dinosaurs in there social group, along with remains of plants, fish, and other reptiles.

Triceratops
The first Tricerops was discovered in 1888 by John Bell Hatcher. Between 1889-1892, Hatcher collected more than 40 skulls and partial skeletons of triceratops.

T-Rex
In 1902 the first Tyrannosaurs rex was unearthed in Montana by Branum Brown. Only about 30 Tyrannosaurus fossils have ever been found, mostly in the western part of the United States but also Canada and east Asia. In 1990 a huge, almost complete T-rex fossil that was found by Susan Hendrickson in South Dakota. It was nicknamed 'Sue' and was sold for $7.6 million at Sotheby's in 1997.

Antarctica Ankylosaurous
In 1987 the first dinosaur skeleton was discovered in Antarctica. This was significant because until that date Antarctica was the only continent that had not yielded a dinosaur bone. They were uncovered by Eduardo Olivero and were discovered to be the remains of a new plant eating dinosaur belonging to the order Orinthischia. This fossil raised debate about the location of Antarctica in the past, how dinosaurs survived the low light levels and whether they migrated or not.

Sinosauropteryx
This was the first of the 'dino-birds', and was discovered in China in 1997. The fossil shows the dinosaur has primitive, hair like feathers. However, analysis of the fossil showed it was only distantly related to Archaeopteryx and so theories on how and when dinosaurs evolved into birds had to be revised. Small dinosaurs with feathers, beaks and other bird like characteristics have since been discovered and show a link to modern day birds.

Futalogkosaurus dukei
One of the biggest dinosaurs ever discovered. Found in Argentina in 2007.

For related articles click onto:
Acid rain and its effect on wildlife
Archaeopteryx
Can starfish grow back their arms?
Caring for the coral reefs
Causes of acid rain
Coral reefs and the greenhouse effect
Conserving fossil fuels
Energy saving light bulbs
Fossil plants
Famous fossils
Fossils: Venericardia
Fossils: Turritella
Fossil Fuels
Fossil fuels: Alternative sources of energy
Fossil hunting at Bracklesham Bay
How are fossils formed?
How many seas are there in the world?
Keystone species
Star Starfish
What is a cuttlefish?
What is a sea anemone?
What is a starfish?
What is a loofah?
What is the greenhouse effect?
What is a sea sponge?
What is a sea cucumber?
What is the difference between an asteroid and a comet?
What is the difference between hibernation and sleep?
What is the difference between a fog and a mist?
What is a fossil?
What is acid rain?
What is fracking?
What is global warming?
What is the greenhouse effect?
What is the Gulf Stream?
Where are fossils found?

Thursday, 2 January 2014

ARCHAEOPTERYX

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Arguably, one of the most famous dinosaur fossils discovered is the feathered Archaeopteryx, which was found in 1861. This dinosaur fossil caused controversy when it was first discovered in 1861.

This feathered dinosaur lived in the late Jurassic period 150 million years ago and showed the link between dinosaurs and birds. Since than more than 20 species of dinosaurs with feathers have been discovered but there remain few examples of this fossil species.

This rare fossil has only been found in the strata of the Jurassic age in Southern Germany. This bird like fossil has a long, narrow nose with small teeth. Its neck is slim and very bird like, but its tail is reptilian and the fingers on the wings are claw like. It has a skull about the same size of a pigeon with large eye sockets and a relatively large brain. Most significantly the creature has bird like feathers around the wings and tail. However, its bones lack the hollow air cavity structures characteristic of birds.

The first discovered specimen is now housed in the British Museum (Natural History), London. A second fossil was discovered in 1877, and this was a better preserved individual. A third example was discovered in 1951. Since then several fossils have been identified as Archaeopteryx which had previously been misnamed due to the lack of feathers present on the fossil.

Wednesday, 1 January 2014

HOW ARE FOSSILS FORMED?

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Fossils have been discovered for many years, although it was not too far back in our history that it was generally believed that fossils could not exist in a world that God created. Since then we have come to accept Darwins' theory of evolution and the existence of prehistoric creatures and plants that lived in a world where man did not yet exist.

Fossils are the preserved remains or trace of a dead organism. They can be formed in several ways. Dead animals and plants can be preserved in amber, peat bogs, tar pits, or in ice. Casts or impressions, such as foot prints, can be covered by layers of sediments which eventually become rock and so preserve the casts. Hard body parts such as bones, shells and leaves, can be covered by layers of sediments and over time the parts are gradually replaced by minerals.

Fossils can be so detailed that they can show fine features such as feathers, scales, spores and even movements in the surrounding sediment. All this gives us a fascination for fossils, especially the really huge dinosaur ones!.

Most organisms decay without leaving a fossil record but sometimes when conditions are favourable for preservation of plant and animal material fossils are created. Fossils can be found throughout the Earths' sedimentary layers including sandstone, mudrocks, siltstone, shale and, limestone. These layers are primarily laid down by moving water, layer upon layer, in a process known as hydrologic sorting.

After the death of an organism sediment may be deposited rapidly on it, which will bury it quickly. Over time more sediment is deposited on the skeleton which is buried deeper.

If conditions are right then some creatures will become fossils. A soft muddy sea bed, low oxygen levels and minimal light help to preserve organic remains. In addition the body must not be disturbed by predators or strong currents. As a result most of the fossils found are marine animals (95%), followed by plants (4.5%), land invertebrates including insects (0.25%), and vertebrates - mostly fish (0.0125%).

The weight of this sediment compacts the sediment grains together and pushes out any water, and the soft sediment slowly turns to rock in a process called Lithification. Minerals contained within the sediment slowly replace the minerals present within the skeleton, filling any voids left as the skeleton dissolves. This leaves a re-mineralised copy of the original skeleton.

Rocks can remain undisturbed buried deep with the bedrock for many millions of years. However, this bedrock can be disturbed by tectonic forces when neighbouring plates collide. If the bedrock is shifted upwards the rock will start to erode and reveal fossils buried within it.

Depending on the geological conditions fossils may be washed up gently on the sandy shore shore if they are preserved in soft clay, or they may have to be carefully extracted from hard rock using hammers.

For related articles click onto:
Acid rain and its effect on wildlife
Archaeopteryx
Can starfish grow back their arms?
Caring for the coral reefs
Causes of acid rain
Coral reefs and the greenhouse effect
Conserving fossil fuels
Energy saving light bulbs
Fossil plants
Famous fossils
Fossils: Venericardia
Fossils: Turritella
Fossil Fuels
Fossil fuels: Alternative sources of energy
Fossil hunting at Bracklesham Bay
How are fossils formed?
How many seas are there in the world?
Keystone species
Star Starfish
What is a cuttlefish?
What is a sea anemone?
What is a starfish?
What is a loofah?
What is the greenhouse effect?
What is a sea sponge?
What is a sea cucumber?
What is the difference between a rock and a stone?
What is the difference between an asteroid and a comet?
What is the difference between hibernation and sleep?
What is the difference between a fog and a mist?
What is a fossil?
What is acid rain?
What is fracking?
What is global warming?
What is the greenhouse effect?
What is the Gulf Stream?
Where are fossils found?