Fauna of the Vala and Choza
Subtitle: Trimerorhachis : including a revision of prevale species
By: Everett Claire Olson --
Series: Fieldiana -- v. 10, no. 21; Chicago Natural History Museum. [Publication] -- no. 745; Publication (Chicago Natural History Museum) -- 745.
Publisher: Chicago Natural History Museum
Published: 1955
Place of publication: Chicago
Subjects: Paleontology -- Texas.; Amphibians, Fossil.; Paleontology -- Permian.