Trochodendroides

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Trochodendroides
Temporal range: Early Cretaceous to Middle Eocene (Albian-Bartonian), 113.2–37.7  Ma
Trochodendroides ellipticum HC212.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Order: Saxifragales
Family: Cercidiphyllaceae
Genus: Trochodendroides
Berry 1922
Species
  • Trochodendroides arctica
  • Trochodendroides flabella
  • Trochodendroides genetrix
  • Trochodendroides rhomboideus
  • Trochodendroides ellipticum
  • Trochodendroides nebrascensis
  • Trochodendroides serrulata

Trochodendroides is an extinct genus of flowering plants belonging to the Cercidiphyllaceae (sometimes called the katsura family). [3] Fossils have been widely recovered from Cretaceous to Paleogene deposits across the Northern Hemisphere, especially in northeastern Russia and parts of North America. [4] It was once thought to be a member of the family known as Trochodendraceae. [3]

Contents

Description

Leaves attributed to Trochodendroides are typically ovate to elliptical in shape, with entire to slightly serrated margins. The most distinctive feature of these leaves is their palmate, brochidodromous venation, in which several primary veins radiate from the base and are interconnected by looping secondary veins—a characteristic used to differentiate them from similar fossil genera. Fossil specimens range in size from small, shrub-like leaves to larger, tree-sized foliage. [4] Although no definitive reproductive structures have been assigned to Trochodendroides, some fossil assemblages have revealed consistent co-occurrence with infructescences assigned to the genus Jenkinsella and pollen-bearing structures like Alasia, suggesting these may represent components of the same plant taxon. [5]

A fossil of Trochodendroides nebrascensis which was found in Hell Creek Archeampelos nebrascensis (HC103).jpg
A fossil of Trochodendroides nebrascensis which was found in Hell Creek

Distribution

Fossils of Trochodendroides are known from North America, Europe, and Asia. In Canada, they have been found in the provinces of Saskatchewan, Alberta, and British Columbia. [1] [6] In the USA, fossils have been discovered in North Dakota, South Dakota, Montana, and Wyoming. [7] In the Old World, fossil remains have been identified in China, [2] Mongolia, [8] Russia, [4] and the UK. [9] The most recent known fossils come from Jilin in China. [2]

Paleoenvironment

Trochodendroides lived in a diverse array of habitats. The earliest known fossils of Trochodendroides have been recovered from the Early Cretaceous deposits of British Columbia and Alberta. [1] These fossils indicate that the genus initially inhabited fluvial–lacustrine environments influenced by volcanic activity. [1] Later Cretaceous records suggest a broader ecological tolerance. Fossils from Santonian of Alberta point to the occupation of coastal plain environments, [10] while specimens from Cenomanian of Russia indicate survival in cooler climates, with estimated winter temperatures of around 5.5 °C. [11] In the Maastrichtian of the Western US, fossils from the Hell Creek Formation show that Trochodendroides grew in what were wetland habitats. [7] [12] Similar environmental preferences are inferred from the Nemegt Formation (such as in the Altan Uul member) [8] of Mongolia, which represented a seasonally wet environment comparable to the modern Okavango Delta in Africa, [13] although the formation also experienced occasional dry periods with intervals of semi-arid conditions. [14] Fossils from the Paleogene of China indicate that those specimens lived in a temperate environment. [2] Modern katsura trees inhabit mountainous regions of Japan and China, where they grow in cool, dense forests with high humidity. [15] [16]

Trochodendroides fossils are usually found alongside conifers such as Metasequoia but also other angiosperms such as Platanus. [7] [2] [11]

References

  1. 1 2 3 4 W. A. Bell. (1956). "Lower Cretaceous Floras of Western Canada". Geological Survey of Canada Memoir.
  2. 1 2 3 4 5 Middle Eocene flora of Huadian, Jilin Province, Northeastern China (2005). "Middle Eocene flora of Huadian, Jilin Province, Northeastern China". Acta Palaeobotanica. 45 (1).{{cite journal}}: CS1 maint: multiple names: authors list (link)
  3. 1 2 "Fossil evidence of initial radiation of Cercidiphyllaceae". www.binran.ru. Retrieved 2025-08-26.
  4. 1 2 3 Golovneva, L. B.; Alekseev, P. I. (2010). "The genus Trochodendroides Berry in the cretaceous floras of Siberia". Palaeobotany. 1: 120–166. doi:10.31111/palaeobotany/2010.1.120. ISSN   2218-7235.
  5. Golovneva, L. B.; Alekseev, P. I. (2017). "Taxonomy and morphological diversity of infructescences Jenkinsella co-occurred with Trochodendroides leaves in the Cretaceous and Paleogene". Palaeobotany. 8: 92–121. doi:10.31111/palaeobotany/2017.8.92. ISSN   2218-7235.
  6. W. A. Bell. (1949). "Uppermost Cretaceous and Paleocene floras of western Alberta". Geological Survey of Canada Bulletin. 13.
  7. 1 2 3 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
  8. 1 2 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
  9. CRANE, P. R. (1981). "Betulaceous leaves and fruits from the British Upper Palaeocene". Botanical Journal of the Linnean Society. 83 (2): 103–136. doi:10.1111/j.1095-8339.1981.tb01224.x. ISSN   0024-4074.
  10. "Milk River #9 (GSC 3934) (Cretaceous of Canada)". PBDB.org.
  11. 1 2 Spicer, Robert A.; Ahlberg, Anders; Herman, Alexei B.; Kelley, Simon P.; Raikevich, Mikhail I.; Rees, Peter M. (2002). "Palaeoenvironment and ecology of the middle Cretaceous Grebenka flora of northeastern Asia". Palaeogeography, Palaeoclimatology, Palaeoecology. 184 (1–2): 65–105. doi:10.1016/S0031-0182(02)00247-X.
  12. Vajda, Vivi; Lyson, Tyler R.; Bercovici, Antoine; Doman, Jessamy H.; Pearson, Dean A. (2013-11-01). "A snapshot into the terrestrial ecosystem of an exceptionally well-preserved dinosaur (Hadrosauridae) from the Upper Cretaceous of North Dakota, USA". Cretaceous Research. 46: 114–122. doi:10.1016/j.cretres.2013.08.010. ISSN   0195-6671.
  13. Holtz, Thomas R. (2014). "Mystery of the horrible hands solved". Nature. 515 (7526): 203–205. doi:10.1038/nature13930. ISSN   1476-4687.
  14. Owocki, Krzysztof; Kremer, Barbara; Cotte, Martin; Bocherens, Hervé (2020-01-01). "Diet preferences and climate inferred from oxygen and carbon isotopes of tooth enamel of Tarbosaurus bataar (Nemegt Formation, Upper Cretaceous, Mongolia)". Palaeogeography, Palaeoclimatology, Palaeoecology. 537: 109190. doi:10.1016/j.palaeo.2019.05.012. ISSN   0031-0182.
  15. Song, Naiqi; Zhang, Jintun (2018). "MULTIVARIATE ANALYSIS OF THE ENDANGERED MEDICINAL SPECIES Cercidiphyllum Japonicum COMMUNITIES IN THE SHENNONGJIA RESERVE, CENTRAL CHINA". CERNE. 24 (3): 180–189. doi:10.1590/01047760201824032499. ISSN   2317-6342.
  16. "Cercidiphyllum magnificum - large-leaf katsura". Finland: Mustila Arboretum . Retrieved 22 December 2019.