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Description
Organisms that lived in the past may leave behind a record of their existence in two ways. They may die and their bodily remains become fossilised, or they may leave behind the traces of their exis...tence, their tracks and their trails. Both kinds of records, body fossils and trace fossils can tell us about how those organisms lived. This programme illustrates how such fossils enable us to reconstruct the evolution on invertebrates with particular reference to their modes of locomotion.
Metadata describing this Open University video programme
Module code and title: S364, Evolution
Item code: S364; 04
First transmission date: 02-04-1981
Published: 1981
Rights Statement:
Restrictions on use:
Duration: 00:24:09
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Producer: Roger Jones
Contributor: S.(Simon) Conway Morris
Publisher: BBC Open University
Keyword(s): Evolution; Fossils; Grand Canyon; Trace fossils
Footage description: Shots of footprints of Apollo astronauts on the Moon and film shots of the astronauts themselves. Commentary explains that the footprints are a form of trace fossil. Still and film shots of the Grand Canyon, U.S.A. Commentary points out that the layering there is made up of sediments which formed on ancient sea beds. Examining a piece of fossil seabed, Simon Conway Morris points out the ripples caused by wave action and also the negative impression of these ripples found in the rocks directly above. He goes on to explain that while fossils of invertebrates are relatively rare, their trace fossils are common in these sedimentary rocks. Film shots of sea anemones, flatworms, molluscs, analid worms and crabs illustrate the evolutionary transition from cridarians to anthropods. Still shots of a fossilised seabed, of the Grand Canyon and of Trinders Range, Australia. Shots of jellyfish together with jellyfish trace fossils and the fossil of an early invertebrate which had developed bilateral symmetry. Shots of a flatworm and of more trace fossils. Commentary explains why most invertebrate fossils and trace fossils belong to bottom dwellers. Shots of worm casts, film of arenicola burrowing in sand and of arenicolite trace fossils. Commentary points out how one can infer what type of animal left particular trace fossils. Shots of cridarian trace fossils, Dolopichorus, made by a sea anemone. Close up shot of the fossil shows a particulate structure inside. Film shots and animated diagrams of present day anemones show how these cridarians feed and move in the sediment. Commenatry explains the nature of the particular content of the cridarian trace fossil shown above. It points out that they are the digested fragments of trilobite, an early arthropod. Shots of coral polips. The programme goes on to look at trace fossils of evolutionarily more advanced animals, those with distinct bilateral symmetry. Shots of flatworms and limpets which show, particularly, their similar forms of locomotion. Time lapse shots of winkles moving over sand. Shots of a trace fossil, scolicia, left by an animal similar to those above. Going higher up the evolutionary scale, the programme looks at the arthropods and their trace fossils. Shots of living arthropods, Peripitus, and af a Devonian trace fossil left by a similar animal. Shots of the Trilobite model at the University of Oalo which shows several trilobites together with their locomotary traces. Shots of a lug worm and a razor shale burrowing in sand. Commentary discusses what can be learned from fossilised burrows. Simon Conway Morris summarised the programme.
Master spool number: HOU3515
Production number: FOUS122X
Videofinder number: 2055
Available to public: no