Hallucigenia

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Hallucigenia
Temporal range: Lower Cambrian – Middle Cambrian
Artist's rendering of Hallucigenia according to the modern interpretation
A fossil of Hallucigenia from the Burgess shale
Scientific classification
Kingdom: Animalia
Phylum: ?Onychophora
Class: ?Xenusia
Order: ?Scleronychophora
Family: Hallucigeniidae
Conway Morris, 1977
Genus: Hallucigenia
Conway Morris, 1977[1]

Hallucigenia is an extinct genus of animal found as fossils in the Middle Cambrian Burgess Shale formation of British Columbia, Canada. Another species is found in the Lower Cambrian Maotianshan shale of China.

Hallucigenia was thought by Stephen Jay Gould to be unrelated to any living species, but most palaeontologists now believe that the species was a velvet worm, a relative of modern arthropods.[2]

Unlike its contemporary Aysheaia, Hallucigenia has very little resemblance to modern Onychophora. The elongated, and clawed legs bear little resemblance to the paired annulated legs of the Onychophora. It is unknown what the spines were made of and how much 'protection' they offered. It is not easy to explain why 30 or more specimens — each thought to have seven pairs of rather long, flexible legs — do not show even one example of paired legs. But at least this reconstruction of the animal can plausibly walk, and the spines serve a reasonable purpose. A picture of this reconstruction as well as a photograph of an actual fossil can be seen on the Geological Survey of Canada's website.[3]

References[change | edit source]

  1. Conway Morris, S. A new metazoan from the Cambrian Burgess Shale of British Columbia. Palaeontology 20
  2. Lewin, Roger (1 May 1992). "Whose View of Life?". Discovery Magazine. http://discovermagazine.com/1992/may/whoseviewoflife52. Retrieved 2009-10-23.
  3. Past lives: Chronicles of Canadian Paleontology: the Hallucigenia flip Geological Survey of Canada