The Lungfish Gnathorhiza and Its Burrows From the Permian of Kansas

Gnathorhiza is represented by both trace and body fossils in the Kansan Lower Permian (Speiser Shale). At the Junction City locality, burrows allow a refinement of the interpretation of the behavior and life habits of the lungfish Gnathorhiza. Gnathorhiza withdrew from adverse environmental conditions into flask-shaped burrows similar to modem lungfish estivation burrows. Evidence that the trace fossils are estivation burrows of lungfish include: morphological and distributional similarities to modem analogs; xeric miospores within the burrows; concurrence of estivating lungfish and Lysorophus at other Permian localities; convergence of Gnathorhiza body fossils to estivation morphology; and sedimentary interpretation consistent with estivation scenario. At the Bushong locality Gnathorhiza bones occur in a series of bonebeds. The percent representation among the individual bone types indicates a sorted sample. The sorting agency is hydrodynamic based on bone element frequency plotted against settling rates, and comparison to the matrix hydrological equivalence. The assemblage is disturbed, transported, and sorted. The Kansan bone sample from Bushong is described and provides an opportunity to determine the variation typical in a large sample of Gnathorhiza. This provides criteria to evaluate characters. The Kansan sample has enough variation that some "distinguishing" characters of other species are within the range of variation and some differences are size related. The characters which best separate Gnathorhiza species are from the skull roof, and are shape related. Canals (path, junctions, depth, and enclosure) are also important. Tooth plate characters are ambiguous because of variation and size and wear changes. AM:PM ratio, ridge length 2, and cusp number are all too variable to differentiate small samples or individuals. The diagnostic characters of Monongahela are based on tooth plates. Angles separate large samples of M. dunkardensis and M. stenodonta but do not separate M. stenodonta from Gnathorhiza. The Kansan sample has skull roof bones (none are known for Monongahela) which ally it with Gnathorhiza. It is recommended to synonymize the Genus Monongahela with Gnathorhiza.

Grantor dc:publisher

University of Kansas

Year dc:date.issued

1991

Author dc:creator

• McAllister, James A.

Statement dc:rights

• This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.

Handle dc:identifier.uri

https://hdl.handle.net/1808/35497

OAI identifier oai:identifier

oai:kuscholarworks.ku.edu:1808/35497