Fecal proxies

By Dulcinea Groff

Dung fungus spores of Sporormiella australis. From Funghi Paradise.

Dung fungus spores of Sporormiella australis. From Funghi Paradise.

Feces of prehistoric organisms remaining in the sediment records harbor information that can lead to a picturesque reconstruction of an ecosystem from long ago.  It is quite remarkable how many examples of fecal proxies exist and provide more information than just an indication of the presence or absence of an animal.  In the early 1800’s, an eccentric paleontologist named William Buckland was the first to describe coprolites or fossilized feces.  When feces become fossilized the organic components are replaced with minerals and any clue as to what the organism ate is replaced.  Therefore, coprolites may not be very useful in understanding the ecology of past environments and organisms.  Instead, other things associated with feces become proxies in paleoecological studies. Continue reading

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Small but Mighty: Insects as Proxies

By Wayne Heideman

Insects have been on the Earth for a long time and their presence can affect their surrounding environment. It is important to look at insects in the past as they can provide us with insight on how they can act in the present and in the future. In a paleoecological sense, insects can be studied in a number of ways. One way is to look at plant-insect interactions through plant fossils (herbivory) and peatlands (habitat). Another technique is through amber and observing the insect in a snapshot of time. Lastly, sediment cores in lakes can capture insect presence, notably Chironomidae (non-biting midges) larvae and Coleoptera (beetles). All three are viable means of observing past insect use but they all have their strengths and weaknesses which should be assessed before using a specific method.

A picture of three different types of insect damage on plants. A) Shows a frass trail as well as an oviposition site marked by the arrow. B) Shows a high degree of herbivory, only leaving fine veins and C) shows areas of leaf case shelter sites. From Wilf 2008.

A picture of three different types of insect damage on plants. A) Shows a frass trail as well as an oviposition site marked by the arrow. B) Shows a high degree of herbivory, only leaving fine veins and C) shows areas of leaf case shelter sites. From Wilf 2008.

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