Anataphrus vigilans Price: $125

Anataphrus vigilans Trilobite: width – 19.25 mm (0.75”) Matrix: length – 31.9 mm (1.25”)       Width – 29.14 mm (1.14”) Clermont Member, Maquoketa Formation Fayette County, Iowa
While Anataphrus vigilans represents the most commonly encountered Maquoketa trilobite only about 1 in 5 specimens are inflated or possess both eyes intact making nice specimens desirably rare. This medium sized specimen is fully inflated and possesses both of its characteristic large eyes. The holochroal eyes, facial suture and terrace lines are easily seen on this handsome caramel colored specimen.

Anataphrus Isotelid asaphids are in desperate need of revision. This has been recognized by many (Whittington, Ross, and Shaw). While working on the descriptions of the Baffin Island fauna (GSA Memoir 62, 1954), Harry Whittington realized that several closely related species (vigilans, gigas & raymondi), earlier referred to the genus Vogdesia, did not share comparable morphological features with the genus type V. bearsi. Whittington also mentions that the Sardeson collection at the University of Minnesota contained related species from both the Prosser member of the Galena Formation as well as the Platteville Formation. A. F. Foerste, 1886, had earlier described the Prosser species as Illaenus minnesotensis while P. Raymond & J. Narraway, 1910, described the unrelated Platteville species as Isotelus simplex. Additional attributed species, since 1954 include: A. laeviurus (Kimmswick Formation) and A. martinensis (Copenhagen Formation). Whittington assigned the type species A. borreaus for the new genus and states that the species A. raymondi is very close to the type but A. vigilans can be distinguished by more elevated eyes and a wider extent of the visual surface. He does not make comparisons with the Prosser species A. minnesotensis which is also closely related to the type. Schuchert earlier (1900) referred the Baffin Island specimens to A. minnesotensis. This has led Bob Sloan to suggest that minnesotensis should be considered a senior synonym for A. borreaus. Anataphrus vigilans was first recognized by Fielding B. Meek & Amos H. Worthen, 1870, from specimens collected in Carroll and Kendall Counties in Illinois. The specimens were found in the Maquoketa Formation during the field work associated with the first Illinois Geological Survey in 1858. During Author Slocum’s 1913 paper on the trilobites of the Maquoketa Formation he elaborated on the description of A. vigilans more fully than Meeks & Worthen. He does mention that the librigena of A. vigilans is finely punctate and Raymond, 1925, states that the entire exoskeleton is similarly finely punctate. While this is common among most of the Isotelid Asaphids Whittington, 1954 does not observe any punctuation, instead making the statement that the “external surface of exoskeleton smooth”. I have not observed any punctuation on any specimens I have collected of either A. vigilans or A. borreaus (minnesotensis).