Eoagnostus
{{Short description|Extinct genus of trilobites}}
{{Automatic taxobox
| fossil_range = {{fossilrange|510|507|terminal Toyonian to early Amgaian (Nephrolenellus multinodus-zone, Ovatoryctocara granulata-zone, earliest Kounamkites-zone)}}
| image =
| image_caption =
| taxon = Eoagnostus
| authority = Resser and Howell, 1938
| subdivision_ranks = Species
| subdivision =
- Eoagnostus roddyi Resser and Howell, 1938 (type)
- Eoagnostus acrorhachis Rasetti and Theokritoff, 1967
}}
Eoagnostus is an extinct genus from a well-known class of fossil marine arthropods, the trilobites. It lived during the terminal Lower Cambrian (Toyonian), until the earliest Middle Cambrian (earliest Kounamkites-zone, part of the lower Amgaian).
Distribution
- Eoagnostus roddyi terminal Lower Cambrian of the United States (Bonnia-zone, Kinzers Shale, Lancaster, New York; Pennsylvania; Vermont)Whittington, H. B. et al. Part O, Treatise on Invertebrate Paleontology. Revised, Volume 1 – Trilobita – Introduction, Order Agnostida, Order Redlichiida. 1997 and the early Middle Cambrian of Newfoundland, and Greenland (around the boundary of Ovatoryctocara-zone, Henson Gletscher Formation).
- Eoagnostus acrorhachis occurs in the terminal Lower Cambrian of the United States (Bonnia-zone, Hatch Hill, New York).
Description
Almost identical to Archaeagnostus, but the frontal lobe of the central raised area of the cephalon (or glabella) is effaced, while the back of glabella is inflated.