The border crabs are ancient proportions with an evolutionary history that extends to 450 million years (Ordovician period) and is generally considered examples of “living fossils”. The world of excavations from the University of West Virginia described a new gender and types of real horse crabs from a sample of the Silori sample that was discovered in Indiana, USA. The 80 million -year gap is clogged in a horseshoe, and has a comprehensive morphology similar to those of Ordovician species.
Ciurcalimulus DiscobobolusHolotype. Sweex tapes – 5 mm. Credit image: James C. Lamsdell, Doi: 10.1098/RSPB.2025.0874.
“Cancer Horseshoa Horse (arrangement XiphosuraIt is a water arthritis determined by the integration of body slices into patience. Dr. James Lamdel From the University of West Virginia wrote in its new paper.
“Four living types are known and show a separate geographical distribution, where one type occurs in the Western Atlantic Ocean (ranging from the Canadian East Coast to the Gulf of Mexico) and three in the western Pacific and northeastern India (extending from southern Japan to the eastern coast of India).”
“The group is famous as an example of the evolutionary conservative proportions and considers to include” typical live fossgies “, although the most modern work has shown frequent environmental transfers within the group to be linked to the development of severe formation.”
“The border crab has a long development history that extends to the late Ordovician (450 million years ago) with two types described from North America and other types a little older (Ordovican, 480 million years ago) was reported but waiting for an official description of Morocco.”
“The origins and development of crabs are badly known, with a 80 million -year gap between these types of Ordovician and the first record of Xiphosurida (border crab that reduced posablemen to one chip) in late Devonian (370 million years).”
“This lack of a fossil record of the Hadorian Cancer in the seminary, the time when other water groups were quickly diverse, making it difficult to determine the timing of the origin of the Xiphosurids and to what extent may the mass extinction may affect the ultimately resulting from the horse’s revision.”
The newly identified species of horseshoe crabs have lived through the seminal, about 424 million years ago.
Bee Ciurcalimulus DiscobobolusThe animal is known from one sample found in 1975 by Samuel C. Serka, the son of a member of Kokomo in the formation of Wabash in Indiana.
“The Kokomo member includes up to 30 meters of accurate dark dollar dolomat, and Silurian is considered a age based on Conodont data.”
“Kokomo sites are primarily famous for their endopterid animals, which occur in one horizon and recognizes the representation of a collective extinction event, although a variety of common algae with Brachiopode and Brichiopods are present alongside the squares near the top of the member at what is sometimes referred to to Brachiopod-Horizon.
“Ciurcalimulus Discobobolus Uropterid horizon is derived and preserved similar to the Europterides, which are pressure fossils with reputation skin. “
Ciurcalimulus Discobobolus It is distinguished from another early crab through a unique group of unknown properties among other types.
“ciracalimulus It is like the most document Ordovician Lunatavis The researcher wrote that the species in the possession of highly rounded positive partners and semi -circular psoriasis lacks the expression of the limits of the side part or the Tergoleral expectations in addition to the multi -shape posabdomen.
However, the New Sex is distinguished from Lunatavis In the absence of the pivotal nodes on the chest and the absence of a marginal edge in the friendship that it determines by the thorra, both of which are in the Ordovician species. “
“The Age of the Silor ciracalimulus He explains that Xiphosura maintains the general formation that has been observed between the Ordovician types that continued after the extinction of the ultimate Ordovician mass, indicating that the event had a limited impact on the development of horse crabs. “
“Throughout its evolutionary history, crabs have achieved a global distribution of horse,” he added.
“However, the first sea cancer is known by the Balotankity Laurelia and Siberia, while the oldest lined lobby cancer was found in Lorentia.”
“The additional discovery of ciracalimulus He points out that Laurentia was an important location for the development of early horseshoe crabs, although a strong historical bias should be recognized in excavation science towards sites in Europe and former European colonies. “
“In this way, Lorentia samples are more likely to be taken more than other Palconine, such as Gondwana, an important consideration given that the oldest crab of horseshoe is currently known is an unwanted type of Morocco.”
the paper It was published on June 18 in The facts of the Royal Society B.
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James C Lamdel. 2025. The first crab of ghostly horses reveals the details of the Xiphosuran Earth plan. Brook. R. Suk. for 292 (2049): 20250874; Doi: 10.1098/RSPB.2025.0874