First megafossil occurrence of Cryosophileae (Arecaceae) in Asia: anatomy, systematics, and biogeography

ABSTRACT

Cryosophileae, one of eight tribes within the palm subfamily Coryphoideae, is now restricted to tropical-subtropical areas of Central America with a few megafossil records in Europe and America. However, no megafossil of the tribe has been reported from Asia. Here, we describe Cryosophiloxylon indicum Kumar et Khan sp. nov. assigned to Cryosophileae based on permineralized palm stem from the latest Maastrichtian (Late Cretaceous) to earliest Danian (early Paleocene) sediments (c. 63–65 Ma old) of the Deccan Intertrappean Beds of Madhya Pradesh, Central India. Cryosophiloxylon indicum is characterized by a Cocos-type general stem pattern, the presence of well-preserved vaginata fibrovascular bundles (fvbs) with 2–>4 elongated metaxylem vessel elements and one phloem strand, tabular parenchyma, fibrous bundles, uniform distribution of fibrous part of fvbs from the periphery towards the centre, and compact ground tissue with oval to elongated parenchymatous cells. The present finding represents the oldest reliable megafossil record of Cryosophileae from India supporting its Gondwanan occurrence and so is important for tracing its migration pathways from India to other continents (North and South America, Europe). The extinction of modern members of the tribe from fossil locality may be related to the intensification of the East Asian monsoon.

KEYWORDS:

• Cryosophileae
• anatomy
• cryosophiloxylon indicum
• biogeography
• Central India
• K-Pg

Acknowledgments

Financial support from the Department of Science and Technology (DST), New Delhi (Ref. no. DST/INSPIRE/03/2019/001456) is gratefully acknowledged. This work was supported by an INSPIRE fellowship awarded to S. K. by The Department of Science and Technology, New Delhi, INSPIRE Code (IF190496). M. K. and S. K gratefully acknowledges the Department of Botany, Sidho-Kanho-Birsha University for providing infrastructural facilities to accomplish this work.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Authors contribution

Both authors contributed to the study’s conception and design. Material preparation, data collection, and analysis were performed by Sanchita Kumar and Mahasin Ali Khan. The first draft of the manuscript was written by Sanchita Kumar. Mahasin Ali Khan read and approved the final manuscript.

Additional information

Funding

This work was financially supported by Sanchita Kumar at the Department of Science and Technology (DST), New Delhi [Ref. no. DST/INSPIRE/03/2019/001456].