Aratichnus igen. nov. from the Eocene-aged Baronia Formation, Àger Basin, Lleida, Spain

Abstract

Aratichnus, new ichnogenus, is described from a lower Eocene-aged, tidally reworked sandstone unit (Baronia Formation) near Baronia de Sant Oïsme, Spain. Aratichnus n. igen. is a horizontal, epichnial furrow ranging from simpler forms that display repeating straight to gently curved grooves to more complex serial furrows paralleling each other. Two new ichnospecies are described, Aratichnus hordeicollis n. isp. and Aratichnus apricuscampus n. isp., that encompass the range of morphological variability exhibited by the ichnogenus. A. hordeicollis exhibits ordered, repeating shapes of furrows, while A. apricuscampus exhibits furrows which do not repeat in shape and direction. We interpret Aratichnus n. igen. as a trace fossil made by an interface deposit feeder exploiting a patchy food source in an intertidal environment.

Keywords:

• Ichnology
• taxonomy
• intertidal
• deposit feeding

Acknowledgements

The authors would like to thank Ron Steel and Robert Dalrymple for their help in the field as well as the NSERC awarded to MKG (RGPIN-2020-0513) and the C.R. Stelck Chair in Petroleum Geology for funding. We would also like to acknowledge the contributions of research assistant Annika Saunders in the preparation of figures. Finally, we would like to heartily thank the reviewers of this manuscript, including Dr. Muñoz and anonymous reviewers, for their comments and suggestions as well as the associate editors, Dr. Netto and Dr. Buatois, for their advice.

Disclosure statement

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