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Drawings by Tibor Perenyi 



The Ancient Fish Traps 



OF MECCA 



RAINER ZANGERL 

 CHIEF CURATOR, GEOLOGY 



A he time was the Pennsylvania)! period, approximately 

 285 million years ago 1 , the place the flat heartland of the 

 present United States, that is now the broad valley of the 

 Mississippi River. Thus roughly located in time and space, 

 we may focus more sharply on a fascinating drama with a 

 geographic and time dimension on the scale of our human 

 experience. 



First we must paint a verbal picture of the landscape as 

 it would have appeared to an observer on the scene — for ex- 

 ample, an insect perched on the frond of a tree fern — near 

 what is now the town of Mecca in west-central Indiana, say 

 in the year 285,000,000 b.c. 



What our insect-observer saw was a vast expanse of 

 swampy forest with a thick spongy pad of peat as a floor. 

 The forested land extended for hundreds of miles along the 

 frayed fringes of a warm, shallow, inland extension of the sea, 

 confined in a basin that almost covered the area now called 

 Illinois. Here and there shallow inlet channels drained the 



swampy coastal plain. The climate was subtropical, rainy 

 seasons alternating with dry ones in yearly cycles. 2 



On the whole it was an extremely serene landscape, and 

 the times had been prosperous, devoid of major disasters. 

 Along the shore of the peaceful sea, marine communities of 

 bottom-dwellers, brachiopods, sea lilies, corals, mussels, and 

 trilobites conducted business-as-usual, and in the swamp a 

 great variety of trees — giant horsetails, scale trees, tree ferns 

 — shot up from the peat floor in rapid succession. But the 

 animal life of the forest itself (probably including many in- 

 sects and some amphibians) is known only to our observer. 



On a fatal day near the end of the rainy season of the year 

 285,000,000 B.C. all this serenity came to an end. Disaster 

 struck both the busy shore life of the sea and the lush tree 

 community of the coastal belt. Our insect-observer could 

 not figure out what caused the upheaval, but he thought he 

 felt a slight earth tremor shaking his perch just before great 

 waves rolled in from the sea, churning up the bottom on 



