Cruziana

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Sequences (Formations)

• C5 Sequence (Waynesville: Liberty)
• C4 Sequence (Sunset: Oregonia)
• C3 Sequence (Corryville)
• C2 Sequence (Miamitown: Fairview)
• C1 Sequence (Clay’s Ferry: Kope)

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Hasiotis (KU, 2013):

• Description: Elongate, bilobate ribbon-like furrows with medial ridges (concave epirelief) or medial grooves (convex hyporelief) and furrows are covered by a herring-bone-like, transverse, longitudinal striations.
• Interpretations: Crawling trail, dwelling or feeding burrow, or digging trace of a deposit-feeding organism; shallow-marine settings and some freshwater deposits like flood plains, fluvial channels, and lacustrine deposits; trilobites, arthropods, brachiopods, and some vertebrates

Zonneveld et al. (2002):

• Cruziana from the Toad and Liard formations are characterized by deep, prominent, transverse-to-oblique grooves or scratchmarks. In addition to these prominent scratchmarks, thin surficial striae, interpreted as secondary scratchmarks, also occur. These burrows are primarily horizontal to sub-horizontal although vertical shafts were associated with some specimens, and range in width from 1.4 cm to 7.5 cm. The longest specimen observed was 160 cm in length, although it had broken ends and originally may have been much longer. Tunnel pathways of larger specimens (width >5 cm) are straight to gently curved and commonly bisect smaller examples. Tunnel pathways of smaller examples ( width Rusophycus occur within many longer specimens of Cruziana.

Fossils of Ohio (1996):

• The ichnogenera Rusophycus and Cruziana , for instance, grade into one another; they are distinguished from one another by their relative lengths.
• Cruzianais an elongate trace that has two lobes. A depression runs down the center of the ichnofossil between the two lobes. Ridges cross each of the two lobes. This trace could be confused with Rusophycus, but that form is shorter. If a specimen is at least about four times as long as wide, it can safely be assigned to the ichnogenus Cruziana. Cruziana could also be confused with Psammichnites, but Psammichnites has a distinctive medial ridge when preserved in positive relief. Cruzianaprobably represents the moving or grazing sites of arthropods. Most Cruzianaichnofossils probably were formed by trilobites, but examples of Cruzianahave been found in Chagrin Shale Member, a rock unit without known trilobites.

Treatise on Invertebrate Paleontology, Part W, Miscellanea Supplement 1 (1975):

• “Elongate bandlike furrows covered by herringbone-shaped ridges, with of without 2 outer smooth or finely longitudinally striated zones outside V-markings occasionally with lateral grooves and/or wisp markings; variability in size and sculpture due to varied behavior of producer and preserved width of trail (0.5 to about 0.8 cm); length up to more than 1 m, commonly 10 to 20 cm; V-angle quite variable, acute to blunt, along length of an individual trail.” W. Hantzschel, 1975
• Interpretations: V- markings are scratch marks made by appendages of producer, certainly mostly by digging activity of endopodites of trilobites; V-markings grouped in sets of distinct parallel claw markings produced by multiple or serrate claws, thus consisting of 2 or more parallel or slightly diverging grooves. (interpretation was very controversially discussed in many publications from 1881-87; some regarded Cruziana as plants or sponges (Delgado, 1885; Lebesconte, 1883a,b; de Saporta 1884), but Nathorst (1881a, 1886) argued for trace fossil nature; for a short account of this controversy see Osgood, 1970, p. 287. Occurrences in France were regarded as “pas de boeuf” or even as “monument druidique” (see Deslongchamps, 1856, p. 299; Fauvel, 1868; Moriere, 1879). These forms now are generally regarded as made by furrowing, burrowing, or shoveling trilobites or trilobite-like arthropods, in part perhaps of merostome origin, and have also been found in freshwater deposits, questionably attributed to notostracan branchiopods (Bromley & Asgaard, 1972); originated by simple ploughing using all or only anterior appendages; lateral ridges may be made by dragging of genal spines; trails may also possess additional impressions of coxae, pleural spines, exopodites and/or carapace edges; produced at mud-sand interface or in muddy sediment by burrowing beneath a sand layer (birkenmajer & Bruton, 1971, p. 315). For undertrack trails see Seilacher (1970, p. 448).V-shaped pattern points in opposite direction to that of animal’s movement, V’s gape forward; for many conclusions from studies of Cruziana on morphology of trilobites legs, trilobite motion and behavior, gradients in digging direction, and preservation, see Seilacher (1962; 1970, fig. 1-6), Crimes (1970b,c), Birkenmajer & Bruton (1971, p. 314, 317). Intermediate forms between Cruziana, Rusophycus, and Diplichnites have been observed; Cruziana and Rusophycuswere often regarded as synonyms, but Lessertisseur (1955, p. 45), Seilacher (1955, p. 366), and particularly Osgood (1970, p. 303) recommended restricting Rusophycusto naming the short bilobate forms Cruziana; however, Seilacher (1970) did not follow that suggestion and placed all “resting tracks,” “resting nests,” and “resting burrows” in Cruziana. Owing to the difficulties in separating Cruziana and Rusophycus, it seems best “to base the names strictly on morphology” (Osgood, 1970); for discussion of stratigraphic significance of Cruzianasee Crimes (1968, 1969) and Seilacher (1960, 1970); for detailed discussion of the genus see Lebesconte (1883a, p. 59-73), de Saporta (1884, p. 58-89), Delgado (1885, p. 27-68), Desio (940, p. 64-67); Lessertisseur (1955, p. 44-47), Seilacher (1955, p. 364-366) and other papers quoted above.)

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