File:Anomalocaris pennsylvanica (fossil anomalocaridid) (Kinzers Formation, Lower Cambrian; Getz Quarry, near Rohrerstown, Pennsylvania, USA) 1.jpg

English: Anomalocaris pennsylvanica Resser, 1929 - grasping appendage from a fossil anomalocaridid from the Cambrian of Pennsylvania, USA. (YPM 10425, Peabody Museum of Natural History, Yale University, New Haven, Connecticut, USA) (centimeter scale)

This fossil is from the Kinzers Lagerstätte, a soft-bodied fossil deposit in the Lower Cambrian of Pennsylvania. About 60 species are present in the interval that contains exceptional preservation, of which 25 represent nonmineralizing organisms (principally arthropods, various "worms", algae, and bacteria).

This is the grasping appendage from the front end of an anomalocaridid, a famous large predator in Cambrian oceans (see: www.flickr.com/photos/jsjgeology/32930038790). The appendage is ~6 centimeters long. The matrix is a medium gray mudrock, limonite-stained, with no bedding character evident. The specimen is a bit difficult to discern due to heavy limonite staining. Boundaries between appendage segments are raised and disturbed. The distal-most ventral spines are darker-colored films with aligned striations.

Classification: Animalia, Arthropoda, Dinocarida

Stratigraphy: Kinzers Lagerstätte, Emigsville Member, Kinzers Formation, middle Bonnia-Olenellus Assemblage-zone, mid-Dyeran Stage (= upper Botoman Stage or lower Toyonian Stage), upper Lower Cambrian

Locality: Getz Quarry, north of the eastern end of Chestnut Ridge, north of Spring Valley Road, near the Bethel Road-Spring Valley Road intersection & ~0.65 kilometers northwest of the Rt. 741-Rt. 30 interchange, western side of the town of Lancaster, Lancaster County, southeastern Pennsylvania, USA (~~vicinity of 40° 03' 48.66" North latitude, 76° 21' 59.55" West longitude) (= United States Geological Survey locality "12x"; this locality no longer exists)

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Reference cited:

Resser, C.E. 1929. New Lower and Middle Cambrian Crustacea. Proceedings of the United States National Museum 76(9). 18 pp. 7 pls.