{{short description|Geologic formation in Antarctica}} {{Infobox rockunit | name = Hidden Lake Formation | image = | caption = | type = Geological formation | age = Coniacian<ref>{{Cite journal|last1=Crame|first1=J. A.|last2=Pirrie|first2=D.|last3=Riding|first3=J. B.|date=2006|title=Mid-Cretaceous stratigraphy of the James Ross Basin, Antarctica|url=http://sp.lyellcollection.org/lookup/doi/10.1144/GSL.SP.2006.258.01.02|journal=Geological Society, London, Special Publications|language=en|volume=258|issue=1|pages=7–19|doi=10.1144/GSL.SP.2006.258.01.02|bibcode=2006GSLSP.258....7C |issn=0305-8719|url-access=subscription}}</ref> | period = Santonian | prilithology = Sandstone | otherlithology = Siltstone | namedfor = Hidden Lake | namedby = | region = James Ross Island, James Ross Island group | country = Argentine Antarctica, British Antarctic Territory, Chilean Antarctic Territory | coordinates = {{coord|63.0|S|57.0|W|display=inline,title}} | paleocoordinates = {{coord|63.1|S|63.9|W|display=inline}} | unitof = Gustav Group | subunits = | underlies = Santa Marta Formation | overlies = Whisky Bay Formation | thickness = | extent = | area = | map = Wfm antarctic peninsula islands.png | map_caption = Map of James Ross Island group<br />James Ross Island is number 2 }}

The '''Hidden Lake Formation''' is a Late Cretaceous geologic formation in Antarctica. The sandstones and siltstones of the formation were deposited in a deltaic environment.

Indeterminate megalosaur remains have been recovered from it.<ref name="dinosaurdistribution">Weishampel, et al. (2004). "Dinosaur distribution" pp. 517–607. in Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): ''The Dinosauria'', 2nd, Berkeley: University of California Press. 861 pp.&nbsp;{{ISBN|0-520-24209-2}}. " pp. 517–607.</ref> Also many plant fossils and ichnofossils of ''Planolites sp.'' and ''Palaeophycus sp.'' have been found in the formation.<ref name=Fossilworks>[https://paleobiodb.org/classic/displayCollResults?collection_no=47823 Hidden Lake] at Fossilworks.org</ref>

==Paleofauna== *Megalosauroidea indet.<ref name="dinosaurdistribution" /> *''Palaeophycus'' sp.<ref name=Fossilworks /> *''Planolites'' sp.<ref name=Fossilworks />

== Flora ==

* ''Antarctoxylon mixai''<ref>{{Cite journal|last1=Sakala|first1=Jakub|last2=Vodrážka|first2=Radek|date=August 2014|title=A new species of Antarctoxylon : a contribution to the early angiosperm ecosystem of Antarctica during the late Cretaceous|journal=Antarctic Science|language=en|volume=26|issue=4|pages=371–376|doi=10.1017/S095410201300076X|issn=0954-1020|doi-access=free|bibcode=2014AntSc..26..371S }}</ref> * ''Dicotylophyllum''<ref name=":0">{{Cite journal|last1=Kvaček|first1=Jiří|last2=Sakala|first2=Jakub|date=2011-06-01|title=Late Cretaceous flora of James Ross Island (Antarctica) – preliminary report|url=https://journals.muni.cz/CPR/article/view/12809|journal=Czech Polar Reports|language=en|volume=1|issue=2|pages=96–103|doi=10.5817/CPR2011-2-9|issn=1805-0697|doi-access=free}}</ref> * ''Elatocladus'' cf. ''heterophylla''<ref name=":0" /> * ''Lygodium'' sp.<ref name=":0" /> * ''Microphyllopteris'' sp.<ref name=":0" />

== See also == * List of dinosaur-bearing rock formations ** List of stratigraphic units with indeterminate dinosaur fossils * List of fossiliferous stratigraphic units in Antarctica ** Snow Hill Island Formation

== References == {{Reflist}}

== Further reading == * V. D. Barreda, S. Palamarczuk, and F. Medina. 1999. Palinología de la Formación Hidden Lake (Coniaciano-Santoniano), Isla James Ross, Antártida. Revista Española de Micropaleontología (31)53-72 * R. E. Molnar, A. L. Angriman, and Z. Gasparini. 1996. An Antarctic Cretaceous theropod. Memoirs of the Queensland Museum 39(3):669-674 * D. Néraudeau, A. Crame, and M. Kooser. 2000. Upper Cretaceous echinoids from James Ross Basin, Antarctica. Géobios 33(4):455-466

Category:Geologic formations of Antarctica Category:Cretaceous System of Antarctica Category:Coniacian Stage Category:Sandstone formations Category:Deltaic deposits Category:Paleontology in Antarctica Category:James Ross Island