21161 - Premium Grade Soft Bodied Xiphosurid (Horseshoe Crab Ancestor) Lower Ordovician
21161 - Premium Grade Soft Bodied Xiphosurid (Horseshoe Crab Ancestor) Lower Ordovician 21161 - Premium Grade Soft Bodied Xiphosurid (Horseshoe Crab Ancestor) Lower Ordovician 21161 - Premium Grade Soft Bodied Xiphosurid (Horseshoe Crab Ancestor) Lower Ordovician 21161 - Premium Grade Soft Bodied Xiphosurid (Horseshoe Crab Ancestor) Lower Ordovician 21161 - Premium Grade Soft Bodied Xiphosurid (Horseshoe Crab Ancestor) Lower Ordovician 21161 - Premium Grade Soft Bodied Xiphosurid (Horseshoe Crab Ancestor) Lower Ordovician

Pictures and Description © Jurassic Dreams

21161 - Premium Grade Soft Bodied Xiphosurid (Horseshoe Crab Ancestor) Lower Ordovician

Sold Out

Learn How To Identify Fossil Fakes with our Free Visual Guide

Species
Xiphosurid (Horseshoe crab ancestor)
Age
Lower Ordovician, Floian stage (~477 Million Years)
Location
North of Zagora, South Morocco
Formation
Upper Fezouata Formation (Outer Feijas Group)
Size
24.7 mm   •    in
Weight
341 g   •    oz
Ref.
us on Facebook to get updates on the rarest fossils!
Description

Xiphosurans are an order of arthropods related to arachnids, or, according to one recent study, actually arachnids. They are sometimes called horseshoe crabs (a name applied more specifically to the only extant family, Limulidae). They first appeared in the Tremadocian (Lower Ordovician) from Fezouata Fm in South Morocco. 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 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.

The conservation of soft parts in the fossil record is somewhat exceptional and only occurs under certain and exclusive taphonomic conditions. For example, anoxic substrates without oxygen, where the organic matter has difficulty decomposing.

The Fezouata Formation occurs in the lower part of the Lower to lower Middle Ordovician Outer Feijas Group, in the western, central and eastern Anti-Atlas
Mountains, southern Morocco (Destombes et al.1985; Gutierrez-Marco & Martin 2016).

It comes from The Konservat-Lagerstätten of Lower Fezouata Fm that spans the entire Tremadoc stage of the Ordovician system and is only present in the Moroccan Anti-Atlas. The discovery of the Fezouata biota in the latest Tremadocian of southeastern Morocco has significantly changed our understanding of the early Phanerozoic radiation. The shelly fossil record shows a well-recognized pattern of macroevolutionary stasis between the Cambrian Explosion and the Great Ordovician Biodiversification Event, but the rich soft-bodied Fezouata biota paints a different evolutionary picture. The Fezouata assemblage includes a considerable component of Cambrian holdovers alongside a surprising number of crown group taxa previously unknown to have evolved by the Early Ordovician. Study of the Fezouata biota is in its early stages, and future discoveries will continue to enrich our view of the dynamics of the early Phanerozoic radiation and of the nature of the fossil record.

CERTIFICATE OF AUTHENTICITY
This is a unique item. A physical certificate of authenticity will be provided. The certificate, elaborated individually by an expert paleontologist, contains an accurate scientific description and the certificate validity can be verified online at all times. In addition, a 100% money back guarantee is provided. Learn more.

 

We display the Wikipedia text under the Creative Commons Attribution-ShareAlike License


The Only Real Specialist. A Certified Paleontologist in Charge

Many turn their hobby into business, they have an online store or sell in eBay. While that can be commendable, it can’t compare with a real expert, with years of academic formation, supervised field work experience, trained in the art of correct identification, detection of fakes, and a solid network of other accredited paleontologists to consult with.

The key facts are being able to guarantee:
Proper Fossil IDAccurate Scientific DescriptionLifetime Warranty

We do that, and in addition we provide a state-of-the-art uniquely numbered, 24/7 online verifiable, hologram-secured Certificate of Authenticity with all the specimens. It is a lifetime warranty: if new discoveries are made that modify the classification of the specimen or there is any inaccuracy, we will re-issue the certificate. On top of that, a 100% Money Back Guarantee in case you simply change your mind: no questions asked.

Why Jurassic Dreams

 
Featured Categories