Henningsmoenicaris Explained

Henningsmoenicaris scutula is a Cambrian genus of arthropod from the Orsten of Sweden.[1] It was formerly named Henningsmoenia, however this name was preoccupied by an ostracod, therefore it was renamed. Its genus name translates to "Henningsmoen's shrimp" after G. Henningsmoen. The species name, scutula is in reference to the large, bowl-shaped carapace.[1]

Morphology

Henningsmoenicaris unusually had an almost 360° field of vision, with two extremely long stalked eyes facing in almost all directions at once, even inwards to give depth perception to the opposite eye.[2] Aside from this, it is a relatively "ordinary" Orsten arthropod with a large bowl-shaped head shield, five pairs of differentiated head appendages including antennules used for swimming, a three-segmented thorax with a pair of appendages on each segment (alongside a ninth pair seemingly still developing in the most developed complete specimen), a five-spined tail segment and a hypostome on the head. The most developed complete fossil is roughly 550 micrometers long, however a trunk fragment of a much larger and more developed specimen suggests even this form is a larva.[1] [3]

Notes and References

  1. Walossek . Dieter . Müller . Klaus J. . Upper Cambrian stem-lineage crustaceans and their bearing upon the monophyletic origin of Crustacea and the position of Agnostus . Lethaia . October 1990 . 23 . 4 . 409–427 . 10.1111/j.1502-3931.1990.tb01373.x. 1990Letha..23..409W .
  2. Schoenemann . Brigitte . Castellani . Christopher . Clarkson . Euan N. K. . Haug . Joachim T. . Maas . Andreas . Haug . Carolin . Waloszek . Dieter . The sophisticated visual system of a tiny Cambrian crustacean: analysis of a stalked fossil compound eye . Proceedings of the Royal Society B: Biological Sciences . 7 April 2012 . 279 . 1732 . 1335–1340 . 10.1098/rspb.2011.1888. 22048954 . 3282376 .
  3. Haug . Joachim T. . Maas . Andreas . Waloszek . Dieter . † Henningsmoenicaris scutula, † Sandtorpia vestrogothiensis gen. et sp. nov. and heterochronic events in early crustacean evolution . Earth and Environmental Science Transactions of the Royal Society of Edinburgh . September 2009 . 100 . 3 . 311–350 . 10.1017/S1755691010008145. 2009EESTR.100..311H .