Paleodictyon
Encyclopedia
Paleodictyon is a pattern, usually interpreted to be a burrow, which appears in the geologic record beginning in the Cambrian and in modern ocean environments. Both irregular and regular nets are known throughout the stratigraphic range of Paleodictyon, but it is the striking regular honeycomb pattern of some forms such as P. carpathecum which make it fascinating and widely studied. Individual mesh elements may be millimeters to centimeters, and entire mesh patterns can cover areas up to a square meter. The edges or threads that make up the mesh are usually cylindrical or ellipsoid in cross-section, and some forms have vertical tubes connecting the mesh upwards to the sediment-water interface
Sediment-water interface
In oceanography and limnology, the sediment-water interface is the boundary between bed sediment and the overlying water column. The topography of this interface is often dynamic, as it is affected by physical processes and biological processes ....

. Dolf Seilacher
Adolf Seilacher
Adolf "Dolf" Seilacher is a German palaeontologist who has made major contributions to evolutionary and ecological palaeobiology in a career stretching over 60 years. He won the Crafoord Prize in 1992, the Paleontological Society Medal in 1994 and the Palaeontological Association's Lapworth Medal...

 proposed in 1977 that it may be a trap for food, a mechanism for farming, or a foraging path. Alternatively, it has been suggested that it may be a cast of a xenophyophoran
Xenophyophore
Xenophyophores are marine protozoa, giant single-celled organisms found throughout the world's oceans, at depths of up to 10,641 meters . Xenophyophores are found in the greatest numbers on the abyssal plains of the deep ocean. They were first described as sponges in 1889, then as testate...

 protist
Protist
Protists are a diverse group of eukaryotic microorganisms. Historically, protists were treated as the kingdom Protista, which includes mostly unicellular organisms that do not fit into the other kingdoms, but this group is contested in modern taxonomy...

.

Much modeling work has been done on Paleodictyon. Roy Plotnick, trace fossils researcher at University of Illinois at Chicago, modeled the form as resulting from the iterative modular growth of an unknown organism. Garlick and Miller modeled it as a burrow with a relatively simple burrow algorithm. Subsequent observations on Paleodictyon using Euler graph theory suggest that it cannot be an excavation trace fossil, and that it must therefore be an imprint, body fossil, or be of abiotic origin.

The IMAX
IMAX
IMAX is a motion picture film format and a set of proprietary cinema projection standards created by the Canadian company IMAX Corporation. IMAX has the capacity to record and display images of far greater size and resolution than conventional film systems...

 film Volcanoes of the Deep Sea
Volcanoes of the Deep Sea
Volcanoes of the Deep Sea is a 2003 documentary film directed by Stephen Low in the IMAX format about undersea volcanoes.-Production:Richard Lutz served as Principal Investigator and Lutz and Peter Rona served as Science Directors of the film, which was funded by the National Science Foundation and...

 describes the search for a living animal that produces the Paleodictyon, using the deep-water submersible DSV Alvin
DSV Alvin
Alvin is a manned deep-ocean research submersible owned by the United States Navy and operated by the Woods Hole Oceanographic Institution in Woods Hole, Massachusetts. The vehicle was built by General Mills' Electronics Group in the same factory used to manufacture breakfast cereal-producing...

 near volcanic vents that lie 3500 meters (12,000 feet) underwater in the Mid-Atlantic Ridge
Mid-Atlantic Ridge
The Mid-Atlantic Ridge is a mid-ocean ridge, a divergent tectonic plate boundary located along the floor of the Atlantic Ocean, and part of the longest mountain range in the world. It separates the Eurasian Plate and North American Plate in the North Atlantic, and the African Plate from the South...

. They found and took samples from many of the Paleodictyon nodosum
Paleodictyon nodosum
The Paleodictyon nodosum is the creature which is thought to produce a certain form of Paleodictyon burrows. They are found around mid ocean ridge systems in both the Pacific and Atlantic Oceans. Although scientists have collected many of the burrows of the Paleodictyon nodosum, they have never...

honeycomb burrows, however no creatures were found in any of them. They theorized that the burrows were being used for bacterial farming by whichever creature created them.
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