J Syst Evol ›› 2023, Vol. 61 ›› Issue (6): 1079-1090.DOI: 10.1111/jse.12936

• Research Articles • Previous Articles     Next Articles

First fossil evidence of samaras of Ventilago Gaertn. (Rhamnaceae) from India and its implications

Taposhi Hazra1, Sampa Kundu1, Subir Bera2, Tapan Chakraborty3, and Mahasin Ali Khan1*   

  1. 1 Palaeobotany and Palynology Laboratory, Department of Botany, Sidho-Kanho-Birsha University, Ranchi Road, Purulia, 723104, India;
    2 Centre of Advanced Study, Department of Botany, University of Calcutta, 35, BC Road, Kolkata, 700019, India;
    3 Geological Studies Unit, Indian Statistical Institute, 203, B. T. Road, Kolkata, 700108 West Bengal, India
    *Author for correspondence. E-mail: khan.mahasinali@gmail.com
  • Received:2022-05-17 Accepted:2022-11-29 Online:2022-12-02 Published:2023-11-01

Abstract: The Ventilago Gaertn. (Rhamnaceae) is widely distributed in pantropical areas of Africa, Asia, and Australia. However, fossil records of this taxon are sparse, which limits understanding of the evolution and biogeographic history of the genus. In the present study, we report and describe two new fossil species of Ventilago, V. siwalika sp. nov. from the Miocene sediments of Himachal Pradesh, western Himalaya, and V. pliocenica sp. nov. from the Pliocene sediments of Jharkhand, eastern India based on single-winged samaras. Ventilago pliocenica is characterized by a prominent midvein, obtuse to sub-round apex with mucronate tip, longitudinal secondary veins extending the full length of the fruit, and reticulate nature of higher-order veins, the presence of equatorial rim, the hypanthium, and short pedicel. On the other hand, V. siwalika is characterized by a prominent midvein, obtuse to sub-round apex with mucronate tip, longitudinal secondary veins extending the full length of the fruit, and reticulate nature of higher-order veins. Our discovery represents the first unambiguous fossil record of single-winged samara of Ventilago from India and provides valuable insights into the evolution of this genus. In this paper, we also review its biogeographic history and add new information to understand its hypothetical migration route. Present and earlier records of Ventilago also suggest that this genus was a common forest element during Neogene (Miocene time) in Asia.

Key words: Himachal Pradesh, India, Jharkhand, palaeophytogeography, Ventilago, winged fruits