[Palaeontology, Vol. 54, Part 2, 2011, pp. 397–415] THE CAPSULE: AN ORGANIC SKELETAL STRUCTURE IN THE LATE CRETACEOUS BELEMNITE GONIOTEUTHIS FROM NORTH-WEST GERMANY by LARISA A. DOGUZHAEVA and STEFAN BENGTSON Department of Palaeozoology, Swedish Museum of Natural History, PO Box 50007, SE-104 05 Stockholm, Sweden; e-mails
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[email protected] Typescript received 7 February 2009; accepted in revised form 1 June 2010 Abstract: An unusual, bilaterally symmetrical black struc- A flare along the periphery of the alveolus marks a region ture that embraces the protoconch and the phragmocone where the rostrum was not yet formed, suggesting that the and is overlain by a rostrum has been studied in the Santo- capsule extended beyond the rostrum. Modification of the nian–early Campanian (Late Cretaceous) belemnite genus skeleton in Gonioteuthis comprises a set of supposedly inter- Gonioteuthis from Braunschweig, north-west Germany. The related changes, such as innovation of the organic capsule, structure is here named the capsule. Energy dispersed spec- partial elimination of the calcareous rostrum and a diminish- trometry analyses of the capsule show a co-occurrence of sul- ing of the pro-ostracum, resulting in the appearance of a phur with zinc, barium, iron, lead and titanium, suggesting new type of pro-ostracum that became narrower and shorter their chemical association. The capsule was originally made and lost the spatula-like shape and gently curved growth of organic material that was diagenetically transformed into lines of a median field that are typical for the majority of sulphur-containing matter. The material of the capsule dif- Jurassic and Cretaceous belemnites.