A new species of early Cambrian arthropod reconstructed from exceptionally preserved mandibles and associated small carbonaceous fossils (SCFs) ...

• Main Authors: Harvey, THP, Butterfield, NJ
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2022
• Subjects: Cambrian; mandible; small carbonaceous fossils; Pancrustacea; palaeoecology; Arthropoda; Canada; Mount Clark; Northwest Territories
• Online Access: https://dx.doi.org/10.17863/cam.87475; https://www.repository.cam.ac.uk/handle/1810/340046

AbstractMandibulate arthropods (myriapods, hexapods and crustaceans) account for a major component of extant animal diversity but their origins remain unclear. Here, we re‐examine the record of exceptionally preserved arthropodan microfossils, including mandibles, from the lower Cambrian (Stage 4) Mount Clark Formation, Northwest Territories, Canada. The assemblage comes from a single drillcore horizon and occurs as thousands of small carbonaceous fossils (SCFs) representing disarticulated body parts. The mandibles occur as isolated molar surfaces with an elongate outline, a heavy setal fringe, and a subtle right–left asymmetry. These are sufficiently distinctive to diagnose a new genus and species of arthropod, Masticaris fimbriata. Co‐occurring SCFs include diverse appendage lobes and ventral body fragments, along with spines and setae assignable to 53 morphological categories and occurring either singly or in arrays, including filter plates. Most are plausibly interpreted as belonging to the feeding ...