A Long Mortichnial Trackway of Mesolimulus walchi from the Upper Jurassic Solnhofen Lithographic Limestone near Wintershof, Germany

Abstract

A 9.7 m long trackway was discovered in a plattenkalk quarry near the village of Wintershof, Bavaria, Germany, in 2002. The huge ichnofossil derives from the Lower Tithonian, Upper Jurassic Solnhofen Lithographic Limestone. The trackway is complete from beginning to end and consists of footprints, telson drag impressions, prosoma imprints and is identified as the ichnotaxon Kouphichnium isp. Preserved at the very end of the trackway is a complete specimen of Mesolimulus walchi confirming the trackway as a mortichnia (death march). Trackways and trace makers preserved together in the fossil record are rare and such specimens allow unique insights into behavior and ecology. The events that led to M. walchi preserved in this sediment are unknown; however, a most likely scenario is that the limulid was washed into the lagoonal environment during a harsh storm.

Keywords:

• Mortichnia
• Horseshoe crab, Large trace fossil
• Upper Jurassic
• Solnhofen Lithographic Limestone
• Mesolimulus walchi
• Kouphichnium

ACKNOWLEDGMENTS

We would like to thank the Wyoming Dinosaur Center and Burkhard Pohl for allowing the study of this specimen, whom without the permission this paper would not have been possible. A big thanks to Helmut Tischlinger for consistent help, advice, and early revisions of this manuscript. We are grateful to both Nicholas Minter and Christian Gaillard for critically reviewing this manuscript and suggesting some excellent revisions and additional information. Thanks also go to both William Wahl and Tristan Birkemeier for advice, assistance with photography and supplying helpful comments in order to progress this paper. Additionally, we thank Levi Shinkle and Bryan Miazga for their assistance with images and help physically constructing the specimen in order to photograph. Other thanks go to Raimund Albersdörfer for discussing the original discovery of the described specimen, and supplying important information that otherwise would have been lost. Finally, we are eternally grateful to Adam Smith for creating the entire schematic and thanks to Nobumichi Tamura for constructing parts of the other schematics used; plus the kind help of James Lamsdell and Simon Conway Morris for identifying some relevant papers for this study.