What does xiphosura mean?

Definitions for xiphosura
xipho·sura

This dictionary definitions page includes all the possible meanings, example usage and translations of the word xiphosura.

Princeton's WordNet

  1. Xiphosura, order Xiphosuranoun

    horseshoe crabs and extinct forms

Wikipedia

  1. Xiphosura

    Xiphosura () is an order of arthropods related to arachnids. They are more commonly known as horseshoe crabs (a name applied more specifically to the only extant family, Limulidae). They first appeared in the Hirnantian (Late Ordovician). Currently, there are only four living species. Xiphosura contains one suborder, Xiphosurida, and several stem-genera. The group has hardly changed in appearance in hundreds of millions of years; the modern horseshoe crabs look almost identical to prehistoric genera and are considered to be living fossils. The most notable difference between ancient and modern forms is that the abdominal segments in present species are fused into a single unit in adults. Xiphosura were historically placed in the class Merostomata, although this term was intended to encompass also the eurypterids, whence it denoted what is now known to be an unnatural (paraphyletic) group (although this is a grouping recovered in some recent cladistic analyses). Although the name Merostomata is still seen in textbooks, without reference to the Eurypterida, some have urged that this usage should be discouraged. The Merostomata label originally did not include Eurypterida, although they were added in as a better understanding of the extinct group evolved. Now Eurypterida is classified within Sclerophorata together with the arachnids, and therefore, Merostomata is now a synonym of Xiphosura. One recent study places Xiphosura within the Arachnida as the sister group of Ricinulei.

ChatGPT

  1. xiphosura

    Xiphosura is an order of marine arthropods that includes species commonly known as horseshoe crabs. They are characterized by their long, pointed tail and large, rounded upper shell. Despite their name, horseshoe crabs are more closely related to spiders and scorpions than to crabs.

Webster Dictionary

  1. Xiphosura

    see Xiphura

Wikidata

  1. Xiphosura

    Xiphosura is an order of marine chelicerates that includes a large number of extinct lineages and only four recent species in the family Limulidae, which include the horseshoe crabs. The group has hardly changed in millions of years; the modern horseshoe crabs look almost identical to prehistoric genera such as the Jurassic Mesolimulus, and are considered to be living fossils. The most notable difference between ancient and modern forms is that the abdominal segments in present species are fused into a single unit in adults. Xiphosura were traditionally placed in the class Merostomata, although this term was intended to encompass also the eurypterids, whence it denoted what is now known to be an unnatural group. Although the name Merostomata is still seen in textbooks, without reference to the Eurypterida, some have urged that this usage should be discouraged. The Merostomata label originally did not include Eurypterida, although they were added in as a better understanding of the extinct group evolved. However, as the similarities, which were once thought to tie the group together, are now understood to be symplesiomorphies, it seems that abandoning the term altogether to avoid any confusion arising from these historical usages of the term is the best strategy.

Matched Categories

How to pronounce xiphosura?

How to say xiphosura in sign language?

Numerology

  1. Chaldean Numerology

    The numerical value of xiphosura in Chaldean Numerology is: 2

  2. Pythagorean Numerology

    The numerical value of xiphosura in Pythagorean Numerology is: 5


Translations for xiphosura

From our Multilingual Translation Dictionary

Get even more translations for xiphosura »

Translation

Find a translation for the xiphosura definition in other languages:

Select another language:

  • - Select -
  • 简体中文 (Chinese - Simplified)
  • 繁體中文 (Chinese - Traditional)
  • Español (Spanish)
  • Esperanto (Esperanto)
  • 日本語 (Japanese)
  • Português (Portuguese)
  • Deutsch (German)
  • العربية (Arabic)
  • Français (French)
  • Русский (Russian)
  • ಕನ್ನಡ (Kannada)
  • 한국어 (Korean)
  • עברית (Hebrew)
  • Gaeilge (Irish)
  • Українська (Ukrainian)
  • اردو (Urdu)
  • Magyar (Hungarian)
  • मानक हिन्दी (Hindi)
  • Indonesia (Indonesian)
  • Italiano (Italian)
  • தமிழ் (Tamil)
  • Türkçe (Turkish)
  • తెలుగు (Telugu)
  • ภาษาไทย (Thai)
  • Tiếng Việt (Vietnamese)
  • Čeština (Czech)
  • Polski (Polish)
  • Bahasa Indonesia (Indonesian)
  • Românește (Romanian)
  • Nederlands (Dutch)
  • Ελληνικά (Greek)
  • Latinum (Latin)
  • Svenska (Swedish)
  • Dansk (Danish)
  • Suomi (Finnish)
  • فارسی (Persian)
  • ייִדיש (Yiddish)
  • հայերեն (Armenian)
  • Norsk (Norwegian)
  • English (English)

Word of the Day

Would you like us to send you a FREE new word definition delivered to your inbox daily?

Please enter your email address:


Citation

Use the citation below to add this definition to your bibliography:

Style:MLAChicagoAPA

"xiphosura." Definitions.net. STANDS4 LLC, 2024. Web. 28 Mar. 2024. <https://www.definitions.net/definition/xiphosura>.

Discuss these xiphosura definitions with the community:

0 Comments

    Are we missing a good definition for xiphosura? Don't keep it to yourself...

    Image or illustration of

    xiphosura

    Credit »

    Free, no signup required:

    Add to Chrome

    Get instant definitions for any word that hits you anywhere on the web!

    Free, no signup required:

    Add to Firefox

    Get instant definitions for any word that hits you anywhere on the web!

    Browse Definitions.net

    Quiz

    Are you a words master?

    »
    (law) the act of substituting of one creditor for another
    A nidus
    B epiphora
    C subrogation
    D squint-eye

    Nearby & related entries:

    Alternative searches for xiphosura: