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No. 80: Mar-Apr 1992

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Spider Swordplay

Ventral view of D. raptor spider
Ventral view of D. raptor. The claws are on the tips of the bottom two pairs of legs. Greatly enlarged photos reveal them to be wicked-looking fang-like structures.
D. raptor, a Hawaiian spider, has lost its ability to spin webs and therewith capture prey. This unusual spider, however, has evolved:

"...one of the most remarkable morphological features ever found in spiders (immense elongations of the tarsal claws)."

These claws, just visible on the two lowermost pairs of legs in the sketch, are employed to skewer passing insects in flight:

"The spider is strictly nocturnal, spending most of the activity-period hanging upside down from silk threads. Small insects are snagged directly from the air using a single long claw. For larger insects the spider uses both long claws on legs I, or sometimes all the long claws."

(Gillespie, Rosemary G.; "Impaled Prey," Nature, 355:212, 1992.)

Comment. Nature has produced many remarkable creatures. They become anomalous only if they cannot be explained as the products of small, random, cumulative mutations.

From Science Frontiers #80, MAR-APR 1992. 1992-2000 William R. Corliss

Science Frontiers Sourcebook Project Reviewed in:


  • "A sourcebook of unexplained phenomena is therefore a valuable addition to a collection of scientific literature. William R. Corliss has provided this in the past with his source books of scientific anomalies in several subjects, and now he has provided it for astronomy. He has done an excellent job of collecting and editing a large amount of material, taken in part from scientific journals and in part from scientific reporting in the popular or semi-scientific press." -- "The Mysterious Universe: A Handbook of Astronomical Anomalies", reviwed by Thomas Gold, Cornell University, in Icarus, vol.41, 1980

  • "An interesting, systematic presentation of unusual weather [..] This book is recommended for a general audience" --"Corliss, William R., Tornados, Dark Days, Anomalous Precipitation, and Related Weather Phenomena, Sourcebook Project, 1983.", revieweed in Choice, September 1983
  • "..the science is necessarily somewhat speculative, but Corliss's symthesis is based on reputable sources." -- "Corliss, William R. (Compiler). Lightning, Auroras, Nocturnal Lights, and Related Luminous Phenomena" reviwed by Joseph M. Moran, Univ. of Wisconsin in Science Books and Films, Sep/Oct 1983

  • "Before opening the book, I set certain standards that a volume which treads into dangerous grounds grounds like this must meet. The author scrupulously met, or even exceeded those standards. Each phenomenon is exhaustively documented, with references to scientific journals [..] and extensive quotations" -- "Book Review: The moon and planets: a catalog of astronomical anomalies", The Sourcebook Project, 1985., Corliss, W. R., Journal of the Royal Astronomical Society of Canada, Vol. 81, no. 1 (1987), p. 24., 02/1987