Acta Palaeontologica Polonica

Trilobite-like arthropod from the Lower Cambrian of the Siberian Platform

Andrej Yu. Ivantsov

Acta Palaeontologica Polonica 44 (4), 1999: 455-466

The Lower Cambrian Fossil-Lagerstätte at Sinsk (Sinsk Formation, Lena River, Siberia) yields extraordinarily preserved fossils. A new trilobite-like arthropod from this site, Phytophilaspis pergamena gen. et sp. n., is assigned to the subclass Conciliterga Hou & Bergström, 1997, order and family indet. It is characterized by a large cephalon with facial sutures and relatively large eyes, strongly reduced thorax and very large pygidium. The facial sutures are not connected with the eyes; librigenae preserve marks of segmentation and may represent fused pleurae of the posterior segments of the cephalon. Unlike trilobites, the original mineralization of the carapace was very weak or absent. The new arthropod differs from all of other Conciliterga by the absence of rostral plate, posterior position of eyes and large size of the pygidium.

Key words: Lower Cambrian, Siberian Platform, Fossil-Lagerstätten, Arthropoda, Conciliterga.

Andrej Yu. Ivantsov [], Paleontological Institute, Russian Academy of Sciences, ul. Profsoyuznaya 123, Moscow, 117647 Russia.

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