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Casterolimulus
''Casterolimulus'' is an extinct genus of xiphosuran. It is known from the Late Cretaceous Fox Hills Formation of North America, and it lived in freshwater environments. It is a member of the family Limulidae, and is placed as a close relative of ''Victalimulus ''Victalimulus'' is an extinct genus of horseshoe crab, from Early Cretaceous (Aptian) Koonwarra Fossil Beds in eastern Victoria, Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country c ...'' from the Early Cretaceous of Australia. References Xiphosura {{Paleo-arthropod-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Limulidae
Horseshoe crabs are marine and brackish water arthropods of the family Limulidae and the only living members of the order Xiphosura. Despite their name, they are not true crabs or crustaceans: they are chelicerates, most closely related to arachnids, such as spiders and scorpions. Horseshoe crabs live primarily in and around shallow coastal waters on soft, sandy or muddy bottoms. They are generally found in the intertidal zone at spring high tides. They are eaten in some parts of Asia, and used as fishing bait, in fertilizer and in science (especially ''Limulus'' amebocyte lysate). In recent years, population declines have occurred as a consequence of coastal habitat destruction and overharvesting. Tetrodotoxin may be present in one horseshoe crab species, '' Carcinoscorpius rotundicauda''. Fossil records for horseshoe crabs extend back as far as 480 million years ago, with extant forms being living fossils. A 2019 molecular analysis places them as the sister group of Ricinulei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xiphosuran
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of the entire Phanerozoic. The name is derived from the Latin ''creta'', "chalk", which is abundant in the latter half of the period. It is usually abbreviated K, for its German translation ''Kreide''. The Cretaceous was a period with a relatively warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas. These oceans and seas were populated with now- extinct marine reptiles, ammonites, and rudists, while dinosaurs continued to dominate on land. The world was ice free, and forests extended to the poles. During this time, new groups of mammals and birds appeared. During the Early Cretaceous, flowering plants appeared and began to rapidly diversify, becoming the dominant group of plants across the Earth b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fox Hills Formation
The Fox Hills Formation is a Cretaceous geologic Formation (geology), formation in the northwestern Great Plains of North America. It is present from Alberta on the north to Colorado in the south. Fossil remains of dinosaurs, including tyrannosaurs, as well as large marine reptiles, such as mosasaurs, have been recovered from the formation. Lithology The Fox Hills Formation consists of marginal marine yellow to grey sandstone with shale interbeds. It was deposited as a regressive sequence of barrier islands during the retreat of the Western Interior Seaway in Late Cretaceous time. In its eastern extents, the formation is underlain by the marine Pierre Shale in the United States and by the equivalent Bearpaw Formation in Canada, while in western ranges in Montana and Wyoming it overlies the Lewis Shale. The Fox Hills is overlain by continental sediments of the Laramie Formation in Colorado and the Lance Formation in Wyoming, the later being the equivalent of the overlying Hell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Victalimulus
''Victalimulus'' is an extinct genus of horseshoe crab, from Early Cretaceous (Aptian) Koonwarra Fossil Beds in eastern Victoria, Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma .... The single species, ''V. mcqueeni'', was discovered by James McQueen who was encouraged by Leon Costermans to take it to the Museum of Victoria. Unlike modern species of horseshoe crab, it was likely native to freshwater. References Xiphosura Early Cretaceous arthropods Cretaceous animals of Australia {{Paleo-arthropod-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
