1. First Fossil Record of the Extant Neotropical Genus Dicella Griseb. (Malpighiaceae) from India.
- Author
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Hazra, Taposhi, Manchester, Steven R., and Khan, Mahasin Ali
- Abstract
Premise of research. To date, there is no fossil evidence of the malpighiaceous genus Dicella Griseb. Here, we describe a new fossil species attributed to the modern Dicella Griseb. from the latest Neogene sediments (Rajdanda Formation: Pliocene) of Jharkhand, eastern India. Methodology. The five-winged fruit fossil was revealed by careful removal of the overlying matrix and studied under light compound and inverted fluorescence microscopes. It is identified on the basis of its detailed morphology and through comparison with other modern angiosperm genera having five-winged fruits. Pivotal results. Dicella indica Hazra, Manchester and Khan sp. nov. is characterized by winged fruits with five unequal, narrowly elliptic or obovate enlarged persistent sepals arising hypogynously from a globular nut; the sepals are enlarged with slightly constricted bases and obtuse apexes with venation consisting of a strong midvein and pinnate brochidodromous secondary veins, mixed percurrent tertiary veins, and irregular reticulate quaternary veins. Following comparison with numerous extant genera of angiosperms with propeller-like winged fruits, we conclude that this set of characters is diagnostic for the extant genus Dicella. Conclusions. It is interesting to note that, at present, Dicella does not naturally occur in India and is currently restricted to South America. We hypothesize that its disappearance from the present-day vegetation of eastern India may be related to the gradual intensification of rainfall seasonality since the Pliocene. Our discovery provides valuable insights into the biogeographic history of this genus. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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