The Takatika Grit is a geologic formation in Chatham Islands, New Zealand. It preserves fossils dating back to the Paleocene period, although it also preserves disturbed and re-worked Maastrichtian and Campanian microfossils and tetrapod fossils. A 2017 study found that it dated to late Early to Mid Paleocene on the basis of dinoflagellates. It has been subdivided into two informal units, a lower phosphatic unit containing bones and nodular phosphatic layers, and an upper unit with abundant sponge remains and siliceous microfossils.
Description The two informal units are further subdivided into two units each, the lower is divided into the lower which consists of "poorly sorted, phosphatized grit with abundant phosphorite nodules and bones" and the upper which consists of "nodular bedded sandstone and grit". The upper biosiliceous unit is divided into the lower , which is heavily bioturbated, and the upper "characterized by parallel laminations and sinusoidal ripples".
Paleofauna Paleofauna of the Takatika GritGenusSpeciesLocationStratigraphic positionAbundanceNotes |-Astrophorida indet.indeterminateTiorioriOnly fragmentary spicules are knownAuloplax? (Dactylocalycidae indet.?)A? sp.TiorioriHexactinellid spongeBacillariophyceae indet.IndeterminateTiorioriDiatoms from the Takatika Grit date back to the Danian and CampanianChlamydoselachusIndeterminateTiorioriDinoflagellata indet.Hollis, C.J, Stickley, C.E., Bijl, P.K., Schiøler, P., Clowes, C.D., Li, X, Campbell, H. March 2017. The age of the Takatika Grit, Chatham Islands, New Zealand. Alcheringa 41, xxx–xxx. ISSN 0311-5518.IndeterminateTiorioriDinoflagellates from the Takatika Grit date back to the Danian and CampanianEdaphodonE. kawaiTiorioriElasmosauridae indet.indeterminateTioriorilower (?) Takatika GritAlmost certainly reworked from older sediments.EotretochoneE. australisTiorioriHexactinellid spongeEuretidae indet.IndeterminateTiorioriKupoupouJacob C. Blokland, Catherine M. Reid, Trevor H. Worthy, Alan J.D. Tennyson, Julia A. Clarke, and R. Paul Scofield. 2019. Chatham Island Paleocene Fossils provide insight into the Palaeobiology, Evolution, and Diversity of early Penguins (Aves, Sphenisciformes). Palaeontologia Electronica. 22.3.78; 1-92.K. stilwelliTiorioriPenguinGastropoda indet.IndeterminateTiorioriLithistida indet.IndeterminateTiorioriKnown from scarce weathered fragmentsLycopodiopsida indet.IndeterminateTiorioriMosasauridae indet.IndeterminateTioriorilower (?) Takatika GritAlmost certainly reworked from older sediments.Radiolaria indet.IndeterminateTiorioriRadiolarians from the Takatika Grit date back to the Danian and CampanianParareteP. sp.TiorioriHexactinellid spongeTheropoda indet.IndeterminateTioriorilower (?) Takatika GritVertebral centrum, tibia head, proximal pedal phalanx, manual ungual, proximal manual phalanxInitially suggested to represent evidence of Palaeogene dinosaurs.Fordyce, R. E. 2006. New light on New Zealand Mesozoic reptiles. Geological Society of New Zealand newsletter 140: 6-15.Haw, D. 2002. The discovery of fossils in Mangahouanga Stream. Geological Society of New Zealand newsletter 129: 13-14.Fordyce, R. E. 2003. Fossils and the history of life. Pp 35-64 in Darby, J. T., Fordyce, R. E., Mark, A. F., Probert, P. K., & Townsend, C. R. (eds), The natural history of southern New Zealand. University of Otago Press, Dunedin. 387 p. Almost certainly reworked from older sediments.Tretodictyiidae indet.IndeterminateTioriori
See also Tupuangi Formation
References