Xiphosura
Query URLs
https://term.museum-digital.de/md-de/tag/13143
- Note
- "Xiphosura (/ˌzɪfəˈsjʊərə/) is an order of arthropods related to arachnids, or, according to one recent study, actual arachnids. They are sometimes called 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. They are members of the order Xiphosura, which contains two suborders, Xiphosurida and Synziphosurina.
The group has hardly changed in hundreds of 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." - (en.wikipedia.org 09.03.2020)
References
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