Orthogonium instance of fossil taxon
Orthogonium is a genus of Ediacaran fauna approximately 550-530 million years old. Because of its taphonomy and likeness to other Ediacaran fauna, and as well as to crinoids, paleontologists dispute its classification.Description
The fossil consists of 8 parallel rows of tubes, which are square in cross-section, lying parallel to bedding. These tubes are divided into sections, the longest preserved tube is 58 mm long with 28, mesh-like sections, each of which is 2 mm high and 3 mm wide. Each section is separated from adjacent sections by a defined groove. These square section tubes may represent original pneu structures that did not collapse during fossilization and were filled with sediment, preserving the three-dimensional form of the structure.The fossil resembles several others, particularly Ectenocrinus simplex. This comparison was made by Gürich, who compared the tubes to the likeness of the arms of the crinoids. Mikhail Fedonkin, classified O. parallelum as a quilted petalonam because of its unique preservation. “They resemble sand-filled rocks which were composed of several tubes, often constricted midway by a prominent surface, but what these structures represent is uncertain.” J. John Sepkoski classified Orthogonium as a member of the subphylum Medusae with sister taxa including Bonata, Inaria, and Bronicella.
type of example of manifestation of representation of