Where: Spitsbergen, Norway (78.3° N, 15.9° E: paleocoordinates 69.5° N, 15.6° E)
• coordinate stated in text
• outcrop-level geographic resolution
When: Dorsoplanites ilovaiskyi–Dorsoplanites maximus ammonoid zone, Slottsmøya Member (Agardhfjellet Formation), Tithonian (152.1 - 145.0 Ma)
• 2.5 metres above the Dorsoplanites Bed, Slottsmøya Member, Agardhfjellet Formation, Janusfjellet. Dorsoplanites ilovaiskyi to Dorsoplanites maximus ammonite zones, Middle Volgian (Tithonian; Nagy & Basov, 1998; Collignon & Hammer, 2012; Gradstein et al. in press).
•To further quantify the stratigraphic occurrence of the vertebrate remains, a laterally continuous, sideritic horizon rich in ammonites (especially Dorsoplanites sp.) and bivalves, and a similarly continuous, yellow silt bed were used as marker beds against which the stratigraphic position of each skeleton was measured. The yellow silt bed was set as 0 m. The Dorsoplanites marker bed occurs 27 m above this yellow layer and 21 m below the top of the Slottsmøya Member (Myklegardfjellet Bed; see Collignon & Hammer, 2012), and occurs in the Middle Volgian D. maximus or D. ilovaiskyi zone. The vertical position of each vertebrate specimen was recorded with a Leica TCR 110 total station with <1 cm error at 100 metre distance and later corrected with respect to dip. The specimen described (PMO 219.718) here was found 2.5 metres above the Dorsoplanites bed, and 29.3 metres above the yellow silt layer (Hurum et al. 2012, table 1).
Environment/lithology: deep-water; concretionary, sideritic, black, gray, silty mudstone
Size class: macrofossils
Collected by PMO expedition in 2010
Collection methods: surface (in situ),
• PMO, Natural History Museum, University of Oslo collection
Primary reference: E. M. Knutsen, P. S. Druckenmiller, and J. H. Hurum. 2012. Two new species of long-necked plesiosaurians (Reptilia: Sauropterygia) from the Upper Jurassic (Middle Volgian) Agardhfjellet Formation of central Spitsbergen. Norwegian Journal of Geology 92:187-212 [R. Benson/R. Benson]more details
Purpose of describing collection: taxonomic analysis
PaleoDB collection 134761: authorized by Roger Benson, entered by Roger Benson on 16.10.2012, edited by Jonathan Tennant
Creative Commons license: CC BY (attribution)
Taxonomic list
Reptilia | |
Plesiosauroidea indet. Welles 1943 plesiosaur PMU 24781 comprises an apparently articulated series of two damaged sacrals and 20 caudal vertebrae, together with a highly fractured pelvic girdle, sacral ribs and a femur (possibly Colymbosaurus svalbardensis)
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Spitrasaurus wensaasi n. gen. n. sp.
Spitrasaurus wensaasi n. gen. n. sp. Knutsen et al. 2012 plesiosaur Holotype: PMO 219.718, an articulated postcranial juvenile skeleton including an articulated axial column from the atlasaxis to the 12th dorsal vertebra, cervical and dorsal ribs, numerous gastralia, complete pectoralgirdle and much of the forelimbs, and the right hindlimb.
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