New data on Osteostracans (Agnatha) from the Lower Devonian of the Severnaya Zemlya Archipelago

• Published in: Paleontological Journal
• Main Authors: Afanassieva, Olga B., Karatajūtė-Talimaa, Valentina
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2014
• Subjects: Agnatha; Osteostracans; Morphology; Taxonomy; Lower Devonian; Severnaya Zemlya Archipelago; Severnaya Zemlya; October Revolution Island
• Online Access: http://lmavb.lvb.lt/LMAVB:ELABAPDB6229219&prefLang=en_US

The osteostracans Reticulaspis menneri gen. et sp. nov. and Nucleaspis unica gen. et sp. nov. from the Lower Devonian Severnaya Zemlya Formation of October Revolution Island of the Severnaya Zemlya Archipelago are described. The perfect preservation of the exoskeleton structure of Reticulaspis menneri allows the design and growth mode of the exoskeleton, with a continuous reticular dental surface of the cephalothoracic shield to be characterized. Nucleaspis unica is represented by a juvenile stage, which is extremely scarce in this vertebrate group. The preoccupied generic name Ungulaspis Afanassieva et Karatajūtė-Talimaa, 1998 is replaced by Paraungulaspis