TRAILS AND BURROWS ON THE TIDAL FI^TS OF THE NORTH SEA 

 AND THEIR PA LEON TO LOGIC A L SIGNIFICANCE 



by 



Walter Hantzschel 

 Geologisches Staatsinstitut , Hamburg 



On the German North Sea coast tidal flat deposits are developed as a 

 broad zone between the East and North Frisian Islands and the continent. The 

 sediments of these tidal flats consist of mud, sand, and sandy mud. This tidal 

 region, allowing observations of sedimentation and stratification phenomena, 

 of the formation of ripples and other markings, is therefore a field of work for 

 the giologist and also for the paleontologist. Few other regions on the coasts 

 of the earth offer such a great variety of these phenomena. 



Numerous animals of different groups live on and beneath the surface of 

 these tidal flats, leaving the traces of their activity: traces of their movement, 

 of their feeding in the sedimient or grazing on its surfaces, of resting on or 

 dwelling in the sediment. These traces of their various actions are termed in 

 German "Lebensspuren", a term also used in this German form in Japanese 

 paleontological papers written in English. They are generally to be defined as 

 features in sediments left by living animals. Such trails and burrows are to 

 be seen abundantly on the tidal flats and their study is the object of "ichnology'I 

 They are of great interest to the geologist and paleontologist, especially those 

 occupied with paleoecological studies. In all kinds of sediments of all geologic 

 ages and formations such "trace -fossils" are to be found. There are many 

 sediments in which trace -fossils are the only fossils found, and they are of 

 some importance as proving autochthonous life in such deposits. The study of 

 recent trails and burrows on our coasts, and particularly on the easily access- 

 ible tidal flats, can help much to explore trace -fossils and to use them for 

 paleoecological and paleogeographical investigations of fossil sediments and 

 their environments. Ichnological problems have an only restricted interest for 

 the zoologist; they have become - at least in Germany - a realm of the paleont- 

 ologist. Such investigations may serve as a key for a correct explanation of 

 trace -fossils. The history of paleoichnology shows clearly how the ignorance 

 and disregard of neoichnological investigations led often to misinterpretations 

 of trace -fossils. For some decades since the first descriptions most of them 

 were regarded as marine plants, particularly as different kinds of algae. It 

 was only about 1880 when the Swedish paleobotanist Nathorst and the American 

 paleontologist J. F. James showed conclusively that the explanations of most 

 trace -fossils as marine algae were erroneous. 



The following short review will exhibit what general and special results 

 for paleontological and paleoecological investigations can be obtained from a 

 detailed and careful study of recent trails and burrows. 



One of the most frequent animals of the German tidal flats is the well- 



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