Continental Ichnology Research Laboratory (CIRL)

Department of Geological Sciences, Ohio University

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Welcome to the Continental Ichnology Research Laboratory. The purpose of the CIRL is to investigate the behaviors and biogenic structures (burrows, nests, tracks, trails) produced by modern continental organisms in order to better interpret trace fossils preserved in continental deposits throughout geologic time.

Goals of the CIRL
Research in the CIRL focuses on the burrowing behavior and biogenic structures of extant terrestrial animals for application to the study of ichnofossils. Ichnofossils provide a critically important in situ record of paleoenvironmental and paleoecological change that has become an essential aspect of sedimentology, stratigraphy, and paleontology. By studying the behavior of continental tracemakers, the morphology of their burrows, nests, tracks, and other traces may be correlated to continental environmental factors such as temperature and precipitation, depositional environments, and such substrate characteristics as soil consistency, moisture level, and organic content. In addition, if trace morphology can be linked to specific taxa or body morphologies, then these traces may be used in lieu of body fossils to determine the geographic and temporal range of different groups of organisms.
Current Laboratory Research Animals
Sonoran Desert Millipedes (Orthoporus ornatus) Small (10-15 cm long) millipedes that spend the majority of their lives in the subsurface. They construct long-term dwelling structures in a wide variety of soils and are capable of excavating very dense sediment. These millipedes inhabit semi-arid regions but still require high moisture. Construction of permanent burrows allows these millipedes to construct microhabitats with high humidity.
Giant African Millipedes (Archispirostreptus gigas) One of the largest extant millipedes in the world (18-25 cm long). Giant millipedes produce sinuous burrows that appear to be related to foraging behavior. If humidity drops too low, however, these millipedes will construct U-shaped, temporary dwelling structures. Giant millipedes will only burrow into loose sediment and are unable to penetrate compacted or clay-rich soils.
Ocala Scrub Millipedes (Narceus gordanus) Medium-sized millipedes (6-10 cm long) from Florida that move from the subsurface to the surface during the night to feed. This activity churns the soil, disrupting primary sedimentary structures and leaving irregular, open burrow segments and chambers. The bioturbation of these millipedes overturns the soil moving organic material from the surface to the subsurface.
Emperor Scorpions (Pandinus imperator) One of the largest scorpion species, P. imperator reaches 15-20 cm in length as adults. They inhabit the floor of tropical rain forests in West Africa and exhibit gregarious behavior, living in groups of several individuals within large burrows. Emperor scorpions will construct burrows within a few days if no other shelter is available. These initial burrows are shallow and simple, but they are made deeper and more complex over time. Burrows produced by two or more individuals may have multiple entrances and tunnels that are typically much larger than the scorpions.
Arizona Hairy Desert Scorpion (Hadrurus arizonensis) One of the largest scorpion species in North America, H. arizonensis reaches 14-15 cm in length. The species is found in the North American southwest (Sonoran and Mojave deserts) and is adapted to hot and dry conditions. Hairy desert scorpions are nocturnal predators. They construct elaborate spiral and U-shaped dwelling burrows in consolidated sandy soil (some >2 m deep).
Giant Vinegaroons (Mastigoproctus giganteus) These arthropods are also referred to as whipscorpions and are 2-9 cm in length. They inhabit the southern and southwestern United States. They are nocturnal predators with poor vision but the first two walking legs are modified as sensory appendages. Vinegaroons use their pedipalps to excavate loose to compacted soils and construct a diverse array of burrows from horizontal shafts, U-shaped burrows, helical burrows, and interconnected burrow networks.
Red Trapdoor Spider (Myrmekiaphila sp.) This genus of trapdoor spiders inhabits the southeastern United States. They are 3-8 mm in length and yellowish-red to dark-reddish brown in color. These spiders construct silk-lined burrows covered by a silken trap door. The burrows consist of vertical and horizontal elements. In shallow soils the majority of the burrow may be composed of horizontal tunnels with several chambers and trap doors.
Florida Giant Centipede (Scolopendra alternans ) Originating from the West Indies, these centipedes are now common in Florida. They are very aggressive predators but also spend a significant amount of time in the subsurface. Scolopendra alternans produces dense networks of vertical and horizontal cross-cutting burrows. They burrow by wedging their bodies through the sediment. Sediment is displaced horizontally and compacted but very little is transported to the surface.
Field Research
In addition to laboratory work, research on burrowing organisms in their natural environments is critical to interpreting continental trace fossils. Soils are complex assemblages of biotic and abiotic elements each capable of masking or potentially highlighting the other. In order to make accurate paleoecological interpretations based on continental ichnofossils and paleosols, these modern communities must be studied in the field. My research to date has involved modern soil communities in floodplains and wetlands of eastern Kansas as well as the badlands and prairies of northeastern Colorado. Based on some initial observations during my recent trip to Alaska I am also interested in pursuing research on the tundra subsurface ecosystems of southern Alaska.
Arctic Ground Squirrel (Spermophilus parryii) These small mammals are prolific in the tundra of Alaska. This individual was in the Polychrome Pass area of Denali National Park. Arctic ground squirrels construct maze-like, permanent burrow complexes with several openings. In the winter these openings are sealed and the burrows are used for hibernation. These highly successful animals provide an excellent example of the use of burrows by mammals to survive extreme environmental conditions.
Coming Soon…
This site will contain high quality digital images of biogenic structures produced in the CIRL. Please check back later for more details.
Copyright © 2007 Daniel Hembree Last revised: 11/2009