Foliar herbivory in Late Palaeozoic Cathaysian gigantopterids

Abstract

Foliar feeding traces as evidence of plant–animal interaction are reported for the first time on gigantopterid plants from the Late Palaeozoic Cathaysian flora. Frequently occurring marginal, non-marginal and apical leaf-feeding traces have been identified in two gigantopterid species, Gigantonoclea lagrelii and Gigantonoclea hallei, from the late Early to early Late Permian Shihhotse Formation in northern China. However, foliar herbivory is not recorded on the third gigantopterid present in the same formation, Cathaysiopteris whitei, indicating selective feeding strategies within Cathaysian gigantopterids and the preferential targeting of leaves of Gigantonoclea. Abundant foliar herbivory within Gigantonoclea from the Shihhotse Formation is in stark contrast with many other elements of the same floral assemblages, including plants such as marattialean ferns, sphenophytes and certain other seed-ferns in which foliar herbivory has not been observed. The occurrence of herbivory within gigantopterids from the Cathaysian realm is discussed, and other kinds of plant–animal interactions from Cathaysian floras are summarised in order to present a synthesis to compliment similar data collected for the Late Palaeozoic floras of Euramerica. These new data on foliar herbivory, combined with other evidence of plant–animal interactions in Cathaysian floras, indicate unusually high levels of herbivory on certain gigantopterids compared to previous ideas of foliar herbivory in the Palaeozoic. In combination with evidence previously reported from Euramerica, our results testify to the widespread nature of foliar herbivory on Late Palaeozoic gigantopterids.