# Platanites
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> Source: https://en.wikipedia.org/wiki/Platanites
> Source revision: 1316910774
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{{Short description|Extinct genus of angiosperm}}
{{Automatic taxobox
| fossil_range = [Late Cretaceous](/source/Late_Cretaceous) to [Eocene](/source/Eocene) ([Campanian](/source/Campanian)-[Priabonian](/source/Priabonian)), {{fossil range|83.6|33.9}}
| image = Platanites marginata (HC106).jpg
| image_caption = A specimen of ''Platanites marginata'' from the [Hell Creek Formation](/source/Hell_Creek_Formation)
| taxon = Platanites
| authority = Forbes ex Gardner 1851
| subdivision_ranks = Species
| subdivision = *{{extinct}}'''''Platanites hebridicus '''''
* {{extinct}}'''''Platanites marginatus '''''
* {{extinct}}'''''Platanites montanus'''''
* {{extinct}}'''''Platanites raynoldsii'''''
* {{extinct}}'''''Platanites fremontensis'''''
{{collapsible list|title=Species pending reassessment|
* {{extinct}}'''''Platanites willigeri'''''?
}}
| synonyms = {{collapsible list|bullets = true
|title=Species synonymy
|'' Negundo fremontensis''
}}
}}
'''''Platanites''''' is a genus of extinct [plane tree](/source/plane_tree) ([sycamore](/source/sycamore)) that existed during the [Late Cretaceous](/source/Late_Cretaceous)[{{cite web |title=KJ87153 (DMNH 1250) (Cretaceous of the United States) |url=https://paleobiodb.org/classic/basicCollectionSearch?collection_no=48199&is_real_user=1 |website=PBDB.org}}][{{cite web |title=Eagle Formation VB9602 (Cretaceous of the United States) |url=https://paleobiodb.org/classic/basicCollectionSearch?collection_no=27136&is_real_user=1 |website=PBDB.org}}] as well as the [Paleocene](/source/Paleocene) and [Eocene](/source/Eocene). Fossils are known from [North America](/source/North_America) and [Europe](/source/Europe).[{{Cite journal |last=Nares |first=Francisco R. |last2=Huegele |first2=Indah B. |last3=Manchester |first3=Steven R. |date=2025 |title=Compound-Leaved Platanaceae in the Eocene of Western North America |url=https://www.journals.uchicago.edu/doi/abs/10.1086/732310 |journal=International Journal of Plant Sciences |volume=186 |issue=1 |pages=68–79 |doi=10.1086/732310 |issn=1058-5893|url-access=subscription }}][{{Citation |last=Crane |first=Peter R. |title=Paleobotanical evidence on the early radiation of nonmagnoliid dicotyledons |date=1989 |work=Woody plants — evolution and distribution since the Tertiary |pages=165–191 |url=https://doi.org/10.1007/978-3-7091-3972-1_9 |access-date=2025-08-19 |place=Vienna |publisher=Springer Vienna |isbn=978-3-211-99938-7}}]
==Description==
The leaves of ''Platanites'' are said to be compound with three leaflets.[{{Cite journal |last=PEPPE |first=DANIEL J. |last2=ERICKSON |first2=J. MARK |last3=HICKEY |first3=LEO J. |date=2007 |title=FOSSIL LEAF SPECIES FROM THE FOX HILLS FORMATION (UPPER CRETACEOUS: NORTH DAKOTA, USA) AND THEIR PALEOGEOGRAPHIC SIGNIFICANCE |url=https://doi.org/10.1666/05067.1 |journal=Journal of Paleontology |volume=81 |issue=3 |pages=550–567 |doi=10.1666/05067.1 |issn=0022-3360|url-access=subscription }}] The margins are serrated, with rounded sinuses between the teeth. The petiole is swollen at its base. The terminal leaflet is borne on a short stalk, while the lateral leaflets range from sessile to shortly stalked.[{{Cite journal |last=Chunxia |first=He |last2=Jiyue |first2=Li |last3=Ming |first3=Guo |last4=Yutao |first4=Wang |last5=Chong |first5=Chen |date=2008-07-01 |title=Changes in leaf photosynthetic characteristics and water use efficiency along with tree height of 4 tree species |url=https://www.sciencedirect.com/science/article/pii/S1872203208600645 |journal=Acta Ecologica Sinica |volume=28 |issue=7 |pages=3008–3016 |doi=10.1016/S1872-2032(08)60064-5 |issn=1872-2032|url-access=subscription }}] ''Platanites'' leaves show no evidence for [evergreen](/source/evergreen) adaptations. It was probably [deciduous](/source/deciduous) based on petiole morphology.[{{Citation |last=Johnson |first=Kirk R. |title=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 |date=2002-09-01 |work=The Hell Creek Formation and the Cretaceous-Tertiary boundary in the northern Great Plains: An Integrated continental record of the end of the Cretaceous |pages=0 |editor-last=Hartman |editor-first=Joseph H. |url=https://doi.org/10.1130/0-8137-2361-2.329 |access-date=2025-08-22 |publisher=Geological Society of America |doi=10.1130/0-8137-2361-2.329 |isbn=978-0-8137-2361-7 |editor2-last=Johnson |editor2-first=Kirk R. |editor3-last=Nichols |editor3-first=Douglas J.|url-access=subscription }}] [Utah](/source/Utah) (such as in the [Green River Formation](/source/Green_River_Formation)), [New Mexico](/source/New_Mexico) (such as in the [Nacimiento](/source/Nacimiento_Formation) and [Ojo Alamo Formations](/source/Ojo_Alamo_Formation)), [Wyoming](/source/Wyoming) (such as in the [Eagle](/source/Eagle_Sandstone) and [Aycross Formations](/source/Aycross_Formation)), [Oregon](/source/Oregon) (such as in the [Clarno Formation](/source/Clarno_Formation)) and [Colorado](/source/Colorado) (such as in the [Denver](/source/Denver_Formation) and [Green River Formations](/source/Green_River_Formation)).