Continental
Ichnology Research Laboratory (CIRL)
Department of Geological Sciences, Ohio
University
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Home Dr. Hembree Research Continental Ichnology Laboratory Students Publications Courses News and Opportunities Links
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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 |
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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. |
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Current Laboratory
Research Animals |
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Sonoran Desert Millipede (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. (Results published in PALAIOS, v.
24, p. 425-439) |
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Giant African Millipede (Archispirostreptus gigas) One of the largest extant millipedes in the world (18-25 cm
long). Giant African millipedes produce sinuous burrows related to foraging behaviors.
If humidity drops too low, however, these millipedes will construct U-shaped
and W-shaped, temporary dwelling structures. Giant African millipedes will
only burrow into loose sediment and are unable to penetrate compacted or
clay-rich soils. (Results published in PALAIOS, v.
24, p. 425-439) |
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North American Millipede (Narceus americanus) Medium-sized millipedes (6-10 cm long) that inhabit the eastern United States and portions of southeast Canada. They typically Occur on temperate to tropical forest floors at a variety of
elevation. These millipedes have high tolerance for dry and cold conditions,
burrowing into the soil to avoid desiccation or freezing. Narceus americanus burrows into a variety of sediments producing vertical, subvertical, helical, and O-shaped burrows. (Results published in Palaeontologia Electronica v. 17) |
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Florida Scrub Millipede (Floridobolus penneri) Medium-sized millipedes (6-10 cm long) from Florida that move from
the subsurface to the soil surface during the night to feed. This continuous
movement acts to churns the soil, disrupting primary sedimentary structures
and leaving behind multiple irregular, open burrow segments and chambers
resulting in increased porosity and permeability. The bioturbation of these
millipedes overturns the soil moving organic material from the soil surface
to the subsurface. They produce vertical, subvertical, helical, J-, and
O-shaped burrows. (Results published in Palaeontologia Electronica v. 17) |
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Emperor Scorpion (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 communal
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, simple ramps, but
are extended into helical or branched complexes over time. Burrows produced
by two or more individuals have tunnels that are typically much larger in
diameter than the scorpions themselves. (Results published in Topics
in Geobiology: Experimental Approaches to
Understanding Fossil Organisms [PDF]) |
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Malaysian Forest Scorpion (Heterometrus spinifer) A large scorpion (10-15 cm) that inhabits tropical forests of
Malaysia and Thailand. These scorpions exhibit some communal behavior but
tend to be more territorial and aggressive than P. imperator. H. spinifer
is a nocturnal predator that generally constructs simple, steeply dipping
ramp-style burrows with varying depth. Two or three individuals may occupy a
burrow for short intervals of time. Female scorpions construct large and
complex burrow networks, modified over time with their young. |
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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 solitary
nocturnal predators. They can construct elaborate spiral and U-shaped
dwelling burrows in consolidated sandy soil (some >2 m deep) that are used
as temporary to permanent dwellings. (Results published in Palaeontologia Electronica v. 15) |
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Dune Scorpion (Smeringurus mesaensis) A small- to medium-sized (5-10 cm) scorpion that inhabits desert
environments with loose, shifting sand in Arizona and California. These
scorpions are well-adapted to dry climates and obtain all of their water from
their prey. S. mesaensis
is a solitary nocturnal predator that constructs simple, shallow burrows in
loose sand or sandy soil. |
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Northwestern Forest Scorpion (Uroctonus mordax) A small- to medium sized (5-10 cm) scorpion that inhabits the
California coast and montane forests of the Cascades and Sierras at
elevations up to 1900 m. While they are most commonly found beneath rocks or
logs, these scorpions will also produce simple, steeply dipping ramp-style
burrows in sandy soils. |
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Giant Vinegaroon (Mastigoproctus giganteus) These arthropods, also referred to as whip scorpions, 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. (Results published in PALAIOS, v.
28, p. 141-162) |
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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 networks of interconnected vertical shafts and horizontal
tunnels. In shallow soils the majority of the burrow may be composed of
horizontal tunnels with several chambers and trap doors at the surface. |
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African Trapdoor Spider (Gorgyrella sp.) Large (3-5 cm) trapdoor spiders that inhabit southern Africa. Gorgyrella constructs simple,
silk-lined, vertical to subvertical shafts often ending in an enlarged
chamber with a single, large silken trapdoor at the surface. Gorgyrella are ambush predators,
rarely leaving their burrows. (Results published in Palaeontologia Electronica v. 18) |
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Western Desert Tarantula (Aphonopelma chalcodes) Large (7-25 cm) ground spiders that inhabit deserts of Arizona
and northern Mexico. These tarantulas construct burrows in sandy soil that
they rarely travel far from except to mate. The burrows are sealed during the
winter and the spider hibernates. Burrows constructed in the laboratory
include large, but simple, subhorizontal tunnels. (Results published in Palaeontologia Electronica v. 20) |
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King Baboon Tarantula (Pelinobius muticus) Large (5-20 cm) ground spiders that inhabit scrublands and
grasslands of East Africa (Kenya, Tanzania). These tarantulas excavate
burrows using their well-developed back legs. Silk is placed at the burrow
entrance to detect vibrations. In the laboratory these spiders have
constructed vertical to subvertical shafts with high chimneys of excavated
sediment built around the burrow entrance leading to subvertical to
horizontal tunnels. (Results published in Palaeontologia Electronica v. 20) |
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Tawny Red Baboon Tarantula (Hysterocrates gigas) Large (10-30 cm), aggressive ground spiders that inhabit tropical
to subtropical forests of Cameroon and Nigeria. They are the largest of the
Old World tarantulas. These tarantulas are reported to construct intricate
burrows within forest soils. In the laboratory these tarantulas have
constructed large diameter, deep burrows composed of vertical to subvertical
shafts leading to branching horizontal tunnels. The burrow networks have
multiple entrances and the tunnels are lightly lined with silk. (Results published in Palaeontologia Electronica v. 20) |
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Wolf Spider (Hogna lenta) Small (1-3 cm) ground spiders that inhabit much of the eastern
United States from Ohio to Florida. Wolf spiders are active and aggressive
hunters that spend most of their time on the surface. They do produce simple,
vertical burrows, however, and females construct deeper burrows once they
have produced an egg case. (Results published in Palaeontologia Electronica v. 18) |
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Florida Giant Centipede (Scolopendra viridis ) 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 viridis 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. |
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Desert Centipede (Scolopendra polymorpha) These burrowing centipedes inhabit
dry, sandy soils of deserts, grasslands, and forests of the southwestern
United States and northern Mexico in regions with a hot semi-arid climate.
They reach lengths of approximately 18 cm and are nocturnal predators that
feed on soil arthropods and small vertebrates. S. polymorpha burrows through a
combination of intrusion, compression, and excavation techniques to produce
J-, U-, and Y-shaped burrows as well as complexes of linked burrows. (Results published in PALAIOS
v. 34, p. 468-489.) |
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Eastern Bark Centipede (Hemiscolopendra marginata) These burrowing centipedes inhabit
moist, organic-rich soils of the southeastern United States in regions with a
generally humid subtropical climate. They reach lengths of approximately 8 cm
and are nocturnal predators that feed on smaller soil arthropods as well as
earthworms, nematodes, and gastropods. H.
marginata burrows by intrusion and limited
excavation to produce J-, U-, and Y-shaped burrows as well as complexes of
linked burrows.. (Results published in PALAIOS
v. 34, p. 468-489.) |
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Darkling Beetle (Tenebrio molitor) These beetles have burrowing larvae that inhabit a variety of substrates
in woodlands. Currently they have a world-wide distribution due to their use
as a food source, but were originally present in Eurasia. Darkling beetles
are generalist omnivores that feed on decaying plant material, fresh plant
material, decaying insects, and fungi. The larvae burrow by intrusion,
compaction, and excavation to produce shallow, open, straight to sinuous
shafts and tunnels with thin, discontinuous linings as well as unlined, ovoid
chambers for pupation. Adults produced vertical escape burrows originating
from the pupation chamber. (Results published in Ichnos v. 28) |
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Darkling Beetle (Zophobas morio) These beetles have burrowing larvae that inhabit a variety of
substrates in woodlands. Currently they have a world-wide distribution due to
their use as a food source, but were originally present in South America.
Darkling beetles are generalist omnivores that feed on decaying plant
material, fresh plant material, decaying insects, and fungi. The larvae
burrow by intrusion, compaction, and excavation to produce shallow to deep,
open, straight to sinuous shafts and tunnels with thin, discontinuous linings
as well as unlined, ovoid chambers for pupation. Adults produced vertical
escape burrows originating from the pupation chamber. (Results published in Ichnos v. 28) |
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Tiger Salamanders (Ambystoma tigrinum) Terrestrial salamanders, typically 15-25 cm in length, with a wide
range across eastern North America from the Gulf Coastal Plain to the
Midwest. A. tigrinum is
characterized by a robust body with four, short well-developed limbs, a broad
head, and a bluntly rounded, broad snout. The tiger salamander is an active
burrower and utilizes burrows as permanent dwellings. Field studies of these
burrows have shown that the burrows may be up to 60 cm below the surface. (Results published in Topics
in Geobiology: Experimental Approaches to
Understanding Fossil Organisms [PDF]) |
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Marbled Salamanders (Ambystoma opacum) Terrestrial salamanders, typically 5-10 cm in length, distributed
across the eastern United States from New England to Florida and as far west
as eastern Texas. A. opacum is
characterized by a small body, short limbs, and a broad head with a blunt
snout. These salamanders spend most of their time in shallow burrows which
are primarily constructed by enlarging holes and cracks already present in
the soil. (Results published in Topics
in Geobiology: Experimental Approaches to
Understanding Fossil Organisms [PDF]) |
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Horned Frog (Ceratophrys cranwelli) A medium-sized (8-13 cm) terrestrial frog endemic to the dry
regions of Argentina. They feed on insects and other animals of similar size.
They normally excavate shallow depressions with their hind legs, but can also
burrow completely below the surface in extreme conditions. At high
temperatures, C. cranwelli
creates a cocoon of skin to trap moisture. |
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Eastern Spadefoot Toad (Scaphiopus holbrooki) A small (4-5 cm) toad endemic to eastern North America. These
toads spend the majority of their lives in deep burrows, coming out to breed during
wet seasons. Spadefoot toads excavate quickly with their hind legs, but move
little sediment up to the surface. The burrows are simple vertical to
subvertical shafts ending in an asymmetrical chamber. (Results published in Palaeontologia Electronica v. 18) |
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Ocellated Sand
Skinks (Chalcides ocellatus) This medium-sized skink (15-30 cm long) inhabits arid
environments from southern Europe, northern Africa, and western Asia. C. ocellatus is a generalist sand
swimmer that is found in sand dunes, gravel plains, and river beds. Sand
skinks burrow by “swimming” through loose sand. While this behavior does not
produce open burrows, it does disrupt primary sedimentary structures and
produces distinctive biogenic structures. (Results published in Palaeontologia Electronica v. 17) |
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Gold Skink (Mabuya multifaciata) Medium-sized, generalist skinks (15-30 cm long) that inhabit a
wide variety of environments. Mabuya
burrow by excavation of the substrate to produce open burrows in sandy soils. (Results published in Topics
in Geobiology: Experimental Approaches to
Understanding Fossil Organisms [PDF]) |
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Field Research |
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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 field-based neoichnological research to date has involved
modern soil communities in floodplains and wetlands of eastern Kansas, the
badlands and prairies of northeastern Colorado, as well as the high desert
and mountains of the Sonoran Desert in Arizona. |
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Continental Neoichnology
Database |
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The Continental Neoichnology
Database is a new website that contains the results of the experiments
conducted in the CIRL including basic descriptions of the animals studied,
their behaviors, and the biogenic structures they produced as well as the
detailed qualitative and quantitative data collected from each study.
Photographs, videos, and downloadable files are available for each of the
animals. The database is designed to facilitate the access of neoichnological
information for educators, students, paleontologists and anyone else interested
in learning about terrestrial burrowing animals, their behaviors, and the
traces they produce in a variety of sediments and soils. |
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Copyright © 2007 Daniel Hembree Last revised: 10/2021 |
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