Английская Википедия:Caryosyntrips

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Шаблон:Short description Шаблон:Automatic taxobox Caryosyntrips ("nutcracker") is an extinct genus of stem-arthropod which known from Canada, United States and Spain during the middle Cambrian.

Description

Файл:20210702 Caryosyntrips camurus frontal appendage mobility.gif

Presumed grasping motion

Файл:20210215 Caryosyntrips size.png

Sizes of various Caryosyntrips specimens, based on the interpretation as radiodonts.

Caryosyntrips was first named by Allison C. Daley, Graham E. Budd in 2010 and the type species is Caryosyntrips serratus. Multiple species had been recovered from the Burgess Shale Formation, Canada, Wheeler Shale and Marjum Formation, United States, and Valdemiedes Formation, Spain. The latter contain a large specimen, which was initially misidentified as a body remain of lobopodian ("Mureropodia apae").

Caryosyntrips is known only from its 14-segmented frontal appendages, which resemble nutcrackers, with the endite (ventral spine)-bearing margin facing each other. the bell-shaped bases might represent movable articulations with the animal's head. Details of endites, terminal spines, segmental boundaries and outer margins differ between species. Other structures remain unknown, although a specimen with paired appendages possibly contain other fragmental head sclerites as well.

Caryosyntrips is thought to have used their frontal appendages in a scissor-like grasping or slicing motion, and were probably durophagous, feeding on hard-shelled organisms.

Taxonomic affinities

As of 2010s, Caryosyntrips was long considered to be a basal radiodont of uncertain position, usually resolved in a polytomy between euarthropod and radiodont branches. however more recent papers have found that it may sit outside of the monophyletic Radiodonta all together. Due to the unusual morphology of the frontal appendages and the limited extent of known remains, its position within the arthropod stem-group remains uncertain.

See also

• Cucumericrus, another stem-arthropod with similar uncertainties.

External links

• Шаблон:Cite web