John E. Pollard

Trace fossils from the Westphalian D of Writhlington Geological Nature Reserve, nr. Radstock, Avon

Trace fossils, recently collected from a disused colliery tip, include xiphosurid arthropod trackways Kouphichnium , sinuous nematode worm burrows Cochlichnus , ostracod grazing trails, conchostracan resting traces, coprolites and a tetrapod footprint. This ichnofauna represents activity patterns of a diverse fauna in marginal muddy sediments of an ephemeral lake. Although this is a unique discovery in Britain, it has close similarities with late Silesian ichnofaunas of eastern Canada and Central France.

Climatic Control of Marine Trace Fossil Distribution

SUMMARY: Marine trace fossils are not generally considered to be useful as climatic indicators, because of their usually long stratigraphic ranges, and because ichnotaxa may have been formed by a variety of different animals. However Ophiomorpha is today formed only in tropical/subtropical sediments. This appears to have been the case in older sediments, back at least to the early Caenozoic. The burrows of spatangoid echinoids forming Scolicia and Bichordites have a wider range (temperate to tropical). Together, and with regard to a few other trace fossils ( Diplocraterion, Lingulichnus, Renichnus , and possibly Cruziana ) these two conspicuous trace fossils offer small but significant climatic indications, if certain safeguards regarding identification are observed.

Climatic control of trace fossil distribution in the marine realm

Abstract Modern coastal and shoreface faunas exhibit strong latitude (climate) controlled distributions. In contrast, most ichnotaxa are long-ranging, and ichnofacies are widely distributed geographically. This is readily explained by the dominantly warmer and more equable climates of much of the past, as well as the diversity of the producers of most ichnotaxa. Nevertheless, in the Pleistocene, and in the Eocene, cool-water ichnofabrics can be recognized. The latitudinal distributions of thalassinidean crustaceans and infaunal spatangoid echinoids are examined because of their propensity to form distinctive and often abundant trace fossils. Three climatic zones are tentatively recognized from modern shore and shoreface sediments, and which are considered to extend back to the Mesozoic: tropical and subtropical with pellet-lined burrows (Ophiomorpha), echinoid burrows and other traces; temperate with echinoid burrows and mud-lined or non-lined thalassinidean burrows (Thalassinoides), but without Ophiomorpha; and arctic (cold waters) with only a molluscan and annelid trace fossil association. Examples demonstrating this climatic trend are drawn from the Cenozoic and Pleistocene.

A History of Ideas in Ichnology

Abstract Although the concept of ichnology as a single coherent field arose in the nineteenth century, the endeavor of understanding traces is old as civilization and involved cultural areas worldwide. In fact, fossil and recent traces were recognized since prehistoric times and their study emerged from the European Renaissance. This progression, from empirical knowledge toward the modern concepts of ichnology, formed a major research field which developed on a global scale. This report outlines the history of ichnology by (1) exploring the individual cultural areas, (2) tracing a comprehensive bibliographic database, and (3) analyzing the evolution of ichnology semiquantitatively and in a graphical form (“tree of ichnology”). The results form a review and synthesis of the history of ichnology, establishing the individual and integrated importance of the different ichnological schools in the world.