Glossary of Scientific Terms and Expressions: P

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A – B – C – D – E – F – G – H – I – J – K – L – M – N – O – P – Q – R – S – T – U – V – W – X – Y – Z

  • palp (= palpus = pedipalp): spider anatomy — the anterior-most leg-like appendage.
  • palpal organ (see bulb)
  • palpus (see palp)
  • paraphyletic (PARE-uh-fuh-let-ik): Gr. παρα- “para-” = alongside of, beside, near, to, beyond, passing by, together, at once + Gr. φυλον “phylon” = a kind, class, race, people, nation; 1. genetics: contrasted with monophletic (q.v.); a group of taxa that consists of all of the descendants of a possibly hypothetical closest common ancestor minus one or more monophyletic groups (most usually one). A paraphyletic group is thus ‘nearly’ monophyletic (consistent with the meaning of the prefix ‘para’, namely ‘near’ or ‘alongside’.)
  • pedipalp (PEHD-ee-pahlp) — see palp.
  • phylogeny (fi-LODGE-un-ee) — Gr. φυλον “phylon” = a kind, class, race, people, nation + Gr. γενεσις “genesis” = producing; 1 genetics: the evolutionary development of any species of organism. Compare: ontogeny (q.v.).
  • phylogenetic (FI-loh-jeh-NET-ik) — Gr. φυλον “phylon” = a kind, class, race, people, nation + Gr. γενετης “genets” = ancestor, begetter, father; 1. genetics: the development or evolution of a particular group of organisms, i.e., the evolutionary history of a group of organisms, especially as depicted in a family tree.
  • polyphyletic (POH-lee-fuh-LET-ik): Gr. πολυς- “poly-” = much, many, very, often + Gr. φυλον “phylon” = a kind, class, race, people, nation; 1. taxonomics — contrasted with monophyletic (q.v.); a group of taxa based on convergence that excludes the common ancestor.
  • pseudocoelomate (SUE-doh-coh-EHL-oh-mahyt): Gr. ψευδης- “pseudes”  = false, lying, untrue + –κοιλωμα- “coeloma” = a hollow, a cavity + the Latin suffix –ate, designating “one acted upon”, thus any animal with an apparent, but false, body cavity: 1. Zoology — any invertebrate with a three-layered body and a pseudocoel, or false cavity, as distinguished from invertebrates with true cavities, or coeloms; in the pseudocoelomates, the coelom was lost or reduced when non-lethal mutations occurred in genes affecting their early development



  • anat. = anatomy; arach. = arachnid; behav. = behavioral; biol. = biological (inclusive of all animals and plants); bot. = botanical (inclusive of all plants); Gr. = Greek; L. = Latin; q.v. = L. quod vide = which see; pl. = plural; taxon. = taxonomy; zool. = zoological (inclusive of all animals).



  • Allaby, Michael, Ed. 1991. The Concise Oxford Dictionary of Zoology. Oxford Press.
  • Beccaloni, Jan. 2009. Arachnids; Glossary, p. 319. University of California Press, p. 56.
  • Gertsch, Willis J., 1979. American Spiders, 2nd Edition: Glossary, pp. 255-260. Von Nostrand Reinhold Company.
  • Howell, W. Mike, and Ronald L. Jenkins. 2004. Spiders of the Eastern United States; Glossary, Chapter X, pp. 341-348. Pearson Education.
  • Jackman, John A. 1997. A Field Guide to Spiders & Scorpions of Texas: Glossary pp. 173-177. Texas Monthly.
  • Kaston, B. J. 1978. How to know the spiders: Index and Pictured Glossary, pp. 267-272. McGraw Hill Company.
  • Preston-Mafham, Rod. 1996. The Book of Spiders and Scorpions; Glossary, pp. 140-141. Barnes & Noble Books, New York.
  • Ubick, D., P. Paquin, P.E. Cusing and V. Roth, editors, 2005. Spiders of North America, Chapter 72: Glossary — pronunciation guide. Published by the American Arachnological Society.
  • Venes, Donald, Ed. 2009. Taber’s Cyclopedic Medical Dictionary, 21st Ed. F.A. Davis Company, Philadelphia.
  • Williams, Tim. 2005. A Dictionary of the Roots and Combining Forms of Scientific Words. Squirrox Press, Norfolk, England.

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