Preliminary palaeobotanical notes on the Early Cretaceous Cintura Formation (Sonora, Mexico)

Abstract

The Cintura Formation of Albian–Cenomanian age in the Cabullona Basin yielded an important fossil flora, including palynomorphs, leaf impressions and fossil trunks. At the base of the Marquechi Member a poorly preserved palynomorph assemblage is recognised. The palynological assemblage is dominated by gymnosperms, mainly by cheirolepidiacean genus Classopollis. A noteworthy feature is the presence of angiosperm pollen grains of the genera Clavatipollenites, Retimonocolpites and Tucanopollis. A rich, diverse and well-preserved macroflora of leaf impressions has been observed in the uppermost part of this formation belonging to the San Juan Member. There are at least eight morphospecies of leaves including an abundance of taxa with possible botanical affinities to the family Sapindaceae. The angiosperm pollen grains together with the sapindalean leaves constitute the oldest record of such remains in Mexico.

Keywords::

• palaeobotany
• palaeopalynology
• mid-Cretaceous
• Cintura Formation
• Sonora
• Mexico

Acknowledgements

The authors thank Antonio Altamira for taking photographs of macrofossils and also an anonymous reviewer and James A. Doyle for their comments and suggestions to improve this manuscript.

Notes

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Additional information

Funding

This work was supported by Mexican Projects [grant number 104515, 82433 (CONACyT)], [grant number 219810, IA101212 (PAPIIT)].