Quereuxia
| Quereuxia | |
|---|---|
| Quereuxia angulata | |
| Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Genus: | †Quereuxia |
Quereuxia is an extinct genus of aquatic angiosperms known from fossil leaves and leaf rosettes primarily dating to the Late Cretaceous period.[1] It also survived into the Paleocene.[2] These plants are notable for their floating growth habit, with morphological features suggesting adaptation to still freshwater environments.[3]
Classification
Morphological studies have confirmed the genus' distinctiveness based on features such as heterophyllous leaf arrangements (both simple and compound), floating rosettes, and submerged rhizomatous growth. Quereuxia angulata, the most well-known species, has often been compared to extant members of Trapa (water chestnut), though differences in growth habit and floral morphology have prevented confident placement within any modern family, leaving its exact taxonomic position unresolved.[3]
Distribution
Fossils are known from Russia,[4] The United States,[5] Canada[6] and Mongolia.[7]
References
- ^ Hickey, Leo J. (2001). "On the nomenclatural status of the morphogenera, Quereuxia and Trapago". Taxon. 50 (4): 1119–1124. doi:10.2307/1224729. ISSN 1996-8175.
- ^ Wing, Scott (February 1994). "Flora of the Ravenscrag formation (paleocene), southwestern Saskatchewan, Canada". Review of Palaeobotany and Palynology. 80 (3–4): 341. doi:10.1016/0034-6667(94)90012-4. ISSN 0034-6667.
- ^ a b Stockey, Ruth A.; Rothwell, Gar W. (January 1997). "The Aquatic Angiosperm Trapago angulata from the Upper Cretaceous (Maastrichtian) St. Mary River Formation of Southern Alberta". International Journal of Plant Sciences. 158 (1): 83–94. doi:10.1086/297417. ISSN 1058-5893.
- ^ "Obeshchayushchiy (PIN collection 3901) (Cretaceous of Russian Federation)". PBDB.org.
- ^ Johnson, Kirk R. (2002-09-01), Hartman, Joseph H.; Johnson, Kirk R.; Nichols, Douglas J. (eds.), "Megaflora of the Hell Creek and lower Fort Union Formations in the western Dakotas: Vegetational response to climate change, the Cretaceous-Tertiary boundary event, and rapid marine transgression", The Hell Creek Formation and the Cretaceous-Tertiary boundary in the northern Great Plains: An Integrated continental record of the end of the Cretaceous, Geological Society of America, p. 0, doi:10.1130/0-8137-2361-2.329, ISBN 978-0-8137-2361-7, retrieved 2025-08-26
{{citation}}: CS1 maint: work parameter with ISBN (link) - ^ Aulenback, Kevin R.; LePage, Ben A. (March 1998). "Taxodium wallissii Sp. Nov.: First Occurrence of Taxodium from the Upper Cretaceous". International Journal of Plant Sciences. 159 (2): 367–390. doi:10.1086/297558. ISSN 1058-5893.
- ^ Khand, Yo.; Badamgarav, D.; Ariunchimeg, Ya.; Barsbold, R. (2000-01-01), Okada, Hakuyu; Mateer, Nlall J. (eds.), "Cretaceous system in Mongolia and its depositional environments", Developments in Palaeontology and Stratigraphy, Cretaceous Environments of Asia, vol. 17, Elsevier, pp. 49–79, retrieved 2025-08-26