Waipara River, M34/f1073: Haumurian, New Zealand
collected by Alexander McKay 1872

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Reptilia - Plesiosauria - Elasmosauridae
Elasmosauridae indet. Cope 1869
1 individual
Zfr 73, part of a large left mandible articulated with the quadrate and squamosal, plus the left paroccipital process. Zfr 91, portion of a large skull including the basioccipital, basisphenoid, part of the right pterygoid, the crushed right squamosal and the right quadrate
    = Alexandronectes zealandiensis n. gen., n. sp. Otero et al. 2016
Otero et al. 2016
see common names

Geography
Country:New Zealand State/province:Canterbury
Coordinates: 43.1° South, 172.6° East (view map)
Paleocoordinates:58.1° South, 150.3° West
Basis of coordinate:stated in text
Geographic resolution:outcrop
Time
Period:Cretaceous Epoch:Late/Upper Cretaceous
10 m.y. bin:Cretaceous 7-8
Key time interval:Haumurian Other zone: Alterbidinium acutulum
Age range of interval:83.60000 - 66.00000 m.y. ago
Stratigraphy
Formation:Conway
Stratigraphic resolution:bed
Stratigraphy comments: Conway Formation, lower Maastrichtian (A. acutulum dinoflagellate zone (Wilson et al. in prep.)).
If Zfr 73 and Zfr 91 were indeed found along the Waipara River (Fig. 1), then they would have been derived from the Conway Formation (Fig. 2), which crops out across a wide area of North Canterbury and southern Marlborough, and has been the main source of marine reptile fossils in the South Island... Recent biostratigraphical work has shown that the Conway Formation in the mid-Waipara River section extends from the Haumurian Stage (Late Cretaceous) up into the Teurian Stage (Early Paleocene) of the local New Zealand time scale, spanning the K/T boundary (Hollis and Strong 2003; Fig. 2).
From the lower/upstream part of the section, the lower part of the formation, upper Haumurian.
Lithology and environment
Primary lithology:massive,concretionary,gray siltstone
Includes fossils?Y
Lithology description: Throughout most of its outcrop area, the Conway Formation is a soft, easily eroded massive dark grey siltstone or silty sandstone in which pervasive bioturbation has all but obliterated primary sedimentary structures. Large subspherical calcareous concretions are a distinctive feature of the unit, particularly in the lower part.
Environment:basinal (carbonate)
Geology comments: The sedimentary and geochemical characteristics of the Conway Formation suggest deposition under poorly oxygenated conditions free from strong currents or wave activity (Warren and Speden 1978). An analogous depositional setting could be a barred submarine depression or series of depressions similar to those of the present day Santa Barbara Basin off California (Warren and Speden 1978).
Taphonomy
Modes of preservation:body
Size of fossils:macrofossils,mesofossils,microfossils
Collection methods and comments
Collection excludes:some macrofossils,some microfossils
Reason for describing collection:general faunal/floral analysis
Collectors:Alexander McKay Collection dates:1872
Collection method comments: Catalogue entries for both specimens indicate that they were probably collected along the Waipara River some time before 1891 and possibly before 1888. They may form part of the collections made for the Museum by Alexander McKay in 1872 (Welles and Gregg 1971, p. 14)
Taxonomic list comments:The Conway Formation contains few macrofossils other than the reptile remains although, in some places where the siltstone has not been completely decalcified, a few species of molluscs have been found. Non-calcareous remains, such as phosphatic-shelled brachiopods, sharks’ teeth, teleost bones and scales, and plant material, are present but uncommon. Rich dinoflagellate assemblages have been used to date individual reptile specimens (Wilson et al. in prep.).
Metadata
Database number:155319
Authorizer:R. Benson, M. Carrano Enterer:R. Benson, M. Carrano
Modifier:P. Wagner Research group:marine invertebrate,vertebrate
Created:2014-04-08 04:16:42 Last modified:2023-11-20 20:42:00
Access level:the public Released:2014-04-08 04:16:42
Creative Commons license:CC BY
Reference information

Primary reference:
50677. N. Hiller and A. Mannering. 2004. Elasmosaur (Reptilia: Plesiosauria) skull remains fromt he Upper Cretaceous of North Canterbury, New Zealand. Records of the Canterbury Museum 18:1-7 [R. Benson/R. Benson]

Secondary references:

86386 J. P. O'Gorman, R. A. Otero, N. Hiller, R. F. O'Keefe, R. P. Scofield and E. Fordyce. 2021. CT-scan description of Alexandronectes zealandiensis (Elasmosauridae, Aristonectinae), with comments on the elasmosaurid internal cranial features. Journal of Vertebrate Paleontology 41(2):1-14 [E. Vlachos/F. Aspromonte]
60213 R. A. Otero, J. P. O'Gorman, N. Hiller, F. R. O'Keefe, and R. E. Fordyce. 2016. Alexandronectes zealandiensis gen. et sp. nov., a new aristonectine plesiosaur from the lower Maastrichtian of New Zealand. Journal of Vertebrate Paleontology 36(2):e1054494:1-14 [M. Carrano/M. Carrano]
79070 J. D. Scanlon. 2006. Dinosaurs and other Mesozoic reptiles of Australasia. In J. R. Merrick, M. Archer, G. M. Hickey, & M. S. Y. Lee (eds.), Evolution and Biogeography of Australasian Vertebrates 265-290 [M. Carrano/M. Carrano]
86483 G. J. Wilson, P. Schiøler, N. Hiller and C. M. Jones. 2005. Age and provenance of Cretaceous marine reptiles from the South Island and Chatham Islands, New Zealand. New Zealand Journal of Geology & Geophysics 48(2):377-387 [E. Vlachos/F. Aspromonte]