Fossil evidence of London’s
past environments
• This set of slides introduces some of the
different types fossils that have been found in
rocks and deposits in the London area.
• From the fossils, we can learn more about
what the past environment was like and what
types of plants and animals were present at
different times in the past.
What are fossils?
• Fossils are the remains of organisms preserved in
rocks or superficial deposits (sediments overlying
bedrock)
• Fossils can be the whole organism (or part of it), but
over time the substance of the organism is changed.
Soft tissues rarely survive, whereas hard parts (such
as shells, bones, and teeth) are more often
preserved.
• Fossils can also be the impressions or traces of an
organism that lived in the past (e.g. burrows, trails,
or footprints)
• Scientists who study fossils are ‘palaeontologists’
Fossils in the chalk under and around London
•
•
Chalk is mostly made up of microscopic shells of marine phytoplankton (a type of
floating algae called coccolithophores that are abundant in the world’s oceans
today) but larger marine organisms are also fossilized in the chalk.
You can learn more about chalk fossils here:
http://www.discoveringfossils.co.uk/chalk_formation_fossils.htm
Fossil sea urchin (many types
still exist today)
http://en.wikipedia.org/wiki/Chalk_Group#m
ediaviewer/File:Fossil_Echinoid_Echinocorys.
jpg (Dlloyd)
A living sea urchin
http://en.wikipedia.org/wiki/Sea_urc
hin#mediaviewer/File:Riccio_Melone
_a_Capo_Caccia_adventurediving.it.j
pg (Marco Busdraghi)
Ammonite fossils have been found in the chalk
• Ammonites are an extinct marine animal.
• The photo on the left is of a fossil from a Jurassic aged rock in Dorset (but
other types of ammonite fossils have been found in chalk).
• The image on the right is an artist’s reconstruction of what it may have
looked like when alive.
http://commons.wikimedia.org/wiki/File:Ammoni
te_Asteroceras.jpg?uselang=en-gb (Dlloyd)
http://en.wikipedia.org/wiki/Ammonite#mediaviewer/File:Ast
eroceras_BW.jpg (Nobu Tamura)
Fossils in the London Clay under and around
London
• Clay is made up of microscopic plate-like particles that result from the
weathering and erosion of rock and are transported by rivers and then
deposited in near shore areas of calm water.
• Remains of organisms get compacted and preserved in this clay-rich mud.
Fossil starfish
The shark teeth are from London Clay.
The shells are from a much younger deposit
called Red Crag found above the London Clay in
parts of Suffolk and Essex.
http://en.wikipedia.org/wiki/London_Clay#mediaviewer/File:OphiuraWether http://commons.wikimedia.org/wiki/File:Fossil_finds_at_Walton_on_th
e_Naze_-_geograph.org.uk_-_1428396.jpg?uselang=en-gb (Derek Voller)
elli-NaturalHistoryMuseum-August23-08.jpg Captmondo)
Fossils in the London Clay under and around
London
• The London Clay also contains fossils of plants (such as
mangrove trees) that washed into the sea.
• From these we know that along the coasts nearby there were
lush, tropical forests, similar to those found in Indonesia
today.
• A famous area for London Clay fossils is the Isle of Sheppey to
the east of London.
• You can learn more about London Clay fossils (and view more
images) here:
http://www.discoveringfossils.co.uk/isle_of_sheppey_fossils.h
tm
Ice Age fossils in and around London
• Over time, ice sheets built up in the Antarctic
and Arctic regions, and sea level dropped - the
area of London became land.
• Many Ice Age fossils have been found in and
around London within the deposits of ancient
streams.
Ice Age fossils in and around London
• There were some brief, warm phases during the Ice Age
(interglacials) when the climate in the London area was warmer
than today.
• During building work in Trafalgar Square, lion and hippopotamus
bones were found in silty deposits from an ancient channel of
the River Thames which once flowed through the square.
• The animals lived about 125,000 years ago. An image of what
Trafalgar Square may have looked like can be seen here. Visit
Natural History Museum website http://www.nhm.ac.uk/aboutus/news/2005/dec/news_7350.html
• And here: http://www.nhm.ac.uk/natureplus/blogs/whatsnew/2014/07/10/londons-wild-times-past-and-present
Ice Age fossils in and around London
• There are fossils of animals in the London area that lived
during colder phases of the Ice Age (glacials) when the climate
was much colder than today.
• Examples include mammoths and woolly rhinos (both are now
extinct)
http://en.wikipedia.org/wiki/Quaternary_extinction_event#mediaviewer/File:Ice_ag
e_fauna_of_northern_Spain_-_Mauricio_Ant%C3%B3n.jpg (Mauricio Anton)