Mesodescolea is a genus of fossil foliage with uncertain affinities from the Early Cretaceous of Argentina[1] and Antarctica.[2] It includes only one species, Mesodescolea plicata.

Mesodescolea
Temporal range: Early Cretaceous
Scientific classification
Kingdom:
(unranked):
Genus:
Mesodescolea

S.Archang.[1]
Species

Taxonomy

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The genus was first erected by Sergio Archangelsky based on material from the Aptian of the Anfiteatro de Ticó formation.[1] The name of the genus is dedicated to the naturalist Horacio Descole. Although it was originally compared to cycadalean genera such as Ctenis and Stangeria, its affinities were originally considered uncertain. Later reinvestigations and emendations cemented the view that Mesodescolea was a member of the Cycadales family Stangeriaceae.[3][4][5] Other authors have proposed that the genus represents a member of the angiosperms with affinities with the ANA grade or Chloranthaceae.[6]

Description

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The genus includes leaves with highly lobed-dissected margins. The venation is hierarchical, with the tertiary veins forming an irregular reticulum. Chloranthoid teeth are present in the margins. The cuticle shows laterocytic stomata, and is characterized by striae and perforated idioblasts.

Paleoecology

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Leaves of Mesodescolea are locally abundant in the deposits of the Anfiteatro de Ticó formation. They are found in association with Ruflorinia/Ktalenia and the conifer Brachyphyllum. The depositional environment is characterized by river deposits, and the fossils show little evidence of transport.[7]

References

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  1. ^ a b c Archangelsky, Sergio (1963). "A new Mesozoic flora from Ticó, Santa Cruz Province, Argentina". Bulletin of the British Museum (Natural History), Geology. 8 (2): 45–62. doi:10.5962/p.313876.
  2. ^ Hernández, Pedro; Azcarate, Valeria (1971). "Estudio paleobotánico preliminar sobre restos de una tafoflora de la península Byers (Cerro Negro), Isla Livingston; Islas Shetland del Sur, Antártica" (in Spanish). {{cite journal}}: Cite journal requires |journal= (help)
  3. ^ Artabe, Analía E.; Archangelsky, Sergio (1992). "LAS CYCADALES MESODESCOLEA ARCHANGELSKY EMEND. ARCHANGELSKY y PETRIELLA 1971 (CRETACICO) y STANGERIA MOORE (ACTUAL) ESTUDIO COMPARATIVO DE LA EPIDERMIS FOLIAR CON MICROSCOPIA ELECIRONICA DE BARRIDO Y TRANSMISION". Ameghiniana (in Spanish). 29 (2): 115–123. ISSN 1851-8044.
  4. ^ Artabe, Analia E.; Stevenson, Dennis Wm. (1999). "Fossil Cycadales of Argentina". Botanical Review. 65 (3): 219–238. Bibcode:1999BotRv..65..219A. doi:10.1007/BF02857630. ISSN 0006-8101. JSTOR 4354347. S2CID 12370067.
  5. ^ Archangelsky, Sergio; Petriella, Bruno (1971). "NOTAS SOBRE LA FLORA FOSIL DE LA ZONA DE TICO, PROVINCIA DE SANTA CRUZ. IX. NUEVOS DATOS ACERCA DE LA MORFOLOGIA FOLIAR DE MESODESCOLEA PLICATA ARCH. (CYCADALES, STANGERIACEAE)" (PDF). Boletín de la Sociedad Argentina de Botánica. 14: 88–94.
  6. ^ Coiro, Mario; Martínez, Leandro C. A.; Upchurch, Garland R.; Doyle, James A. (2020). "Evidence for an extinct lineage of angiosperms from the Early Cretaceous of Patagonia and implications for the early radiation of flowering plants". New Phytologist. 228 (1): 344–360. doi:10.1111/nph.16657. hdl:11336/146478. ISSN 1469-8137. PMID 32400897. S2CID 218618827.
  7. ^ Archangelsky, Sergio (1966). "Estudio de la Formación Baqueró. Cretácico Inferior de Santa Cruz, Argentina". Revista del Museo de La Plata. 5 (28–34): 63–171. ISSN 2545-6377.