Tunneling trilobites: Habitual infaunalism in an Ordovician carbonate seafloor

Research Article| August 01, 2006 Tunneling trilobites: Habitual infaunalism in an Ordovician carbonate seafloor Lesley Cherns; Lesley Cherns 1School of Earth, Ocean and Planetary Sciences, Cardiff University, Cardiff CF10 3YE, UK Search for other works by this author on: GSW Google Scholar James R. Wheeley; James R. Wheeley 1School of Earth, Ocean and Planetary Sciences, Cardiff University, Cardiff CF10 3YE, UK Search for other works by this author on: GSW Google Scholar Lars Karis Lars Karis 2Geological Survey of Sweden, Box 670, SE-751 28 Uppsala, Sweden Search for other works by this author on: GSW Google Scholar Author and Article Information Lesley Cherns 1School of Earth, Ocean and Planetary Sciences, Cardiff University, Cardiff CF10 3YE, UK James R. Wheeley 1School of Earth, Ocean and Planetary Sciences, Cardiff University, Cardiff CF10 3YE, UK Lars Karis 2Geological Survey of Sweden, Box 670, SE-751 28 Uppsala, Sweden Publisher: Geological Society of America Received: 22 Dec 2005 Revision Received: 14 Mar 2006 Accepted: 18 Mar 2006 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2006) 34 (8): 657–660. https://doi.org/10.1130/G22560.1 Article history Received: 22 Dec 2005 Revision Received: 14 Mar 2006 Accepted: 18 Mar 2006 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Lesley Cherns, James R. Wheeley, Lars Karis; Tunneling trilobites: Habitual infaunalism in an Ordovician carbonate seafloor. Geology 2006;; 34 (8): 657–660. doi: https://doi.org/10.1130/G22560.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Asaphus trilobites preserved in tunnel systems of the trace fossil Thalassinoides from the mid-Ordovician (ca. 465 Ma) Holen Limestone, Sweden, are interpreted as the trace makers, enabled by shallow carbonate firm grounds to construct open tunnel networks and develop habitual infaunal behavior. Their in situ preservation confirms an infaunal ethology inferred for some trilobite taxa from functional morphology. We suggest that predation pressure from large omnivorous nautiloid cephalopods (“Orthoceras” Limestone facies) may have triggered ecologic opportunism. In trilobites well adapted for predatory-scavenging behavior as well as excavation, the tunnel networks functioned primarily for protection, possibly assisting in feeding, breathing, and breeding strategies. Previously, “trilobite burrows” have referred to seafloor traces of locomotion, feeding, and resting (Cruziana, Rusophycus). Infaunal, tunneling trilobites provide new evidence of mid-Ordovician partitioning of the skeletal benthos, adding to an ecologic and trophic tier hitherto interpreted as occupied by soft-bodied organisms. Such trilobites also provide an identity for Thalassinoides tracemakers prior to Devonian evolution of decapod crustaceans. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.