Arionellus Explained

Arionellus Barrande, 1850, is a disused name for a genus of trilobite. The name Arionellus was a replacement for Arionides Barrande, 1847, itself a replacement for Arion Barrande, 1846, which was preoccupied because Férussac had already used it in 1819 for a genus of slugs.

Agraulos had already been proposed as replacement for Arion by Hawle and Corda in 1847, but Barrande unjustly considered it a homonym of Agraulis, a butterfly named by Boisduval in 1836.^[1]

The species of Arionellus have now been reassigned to the following genera.^[2]

• A. bipunctatus = Croixana bipunctata
• A. ceticephalus = Agraulos ceticephalus
• A. convexus = Camaraspis convexa
• A. cylindricus = Keithiella cylindrica
• A. oweni = Modocia oweni
• A. primaevus = Strenuaeva primaeva
• A. pustulatus = Glaphurus pustulatus
• A. texanus = Tricrepicephalus texanus
• A. tripunctatus = Tricrepicephalus tripunctatus

Notes and References

1. F.B.. Meek. F.V.. Hayden. 1865. Palaeontology of the upper Missouri – A Report upon Collections made principally by the Expeditions under command of Lieut. G.K. Warren, U.S. Top. Egrs. in 1855 and 1856 – Invertebrates, Part I. Smithsonian Contributions to Knowledge. 14. 1. 7–8.
2. Book: Moore, R.C.. 1959. Arthropoda I - Arthropoda General Features, Proarthropoda, Euarthropoda General Features, Trilobitomorpha. Geological Society of America/University of Kansas Press. Treatise on Invertebrate Paleontology. Part O.. O207, O250, O256, O272, O278, O298, O306, O322. Boulder, Colorado/Lawrence, Kansas. 0-8137-3015-5.