Abstract Despite the enormous paleobotanical record on different islands of the Antarctic Peninsula, the evidence of insect activity associated with fossilized plants is scarce. Here we report the first evidence of insect-plant interaction from Cretaceous deposits, more precisely from a new locality at the Rip Point area, Nelson Island (Antarctic Peninsula). The macrofossil assemblage includes isolated Nothofagus sp. leaf impressions, a common component of the Antarctic paleoflora. Two hundred leaves were examined, of which 15 showed evidence of insect activity, displaying variations in size, shape, and preservation. Two types of interaction damage, galls and mines, were identified. A single specimen retained a circular scar recognized as galling scar, while meandering tracks were considered mines. These traces of herbivore insect activity, correspond to the oldest known record of this type of interaction of West Antarctica and the oldest record of insect-plant interaction in Nothofagus sp. reported so far.

A paleoflora da Formação Crato é uma das poucas floras equatoriais do Cretáceo Inferior. É diversificada, com muitas angiospermas, especialmente representantes dos clados magnoliids, monocotiledôneas e eudico-tiledôneas, confirmando a hipótese de que a diversidade das angiospermas durante a última parte do Cretáceo Inferior era ralativamente alta. A morfologia de uma nova mocotiledônea fóssil é estudada e comparada com outros gêneros de Smilacaceae, especialmente a venação. Cratosmilax jacksoni n. gen. n. sp. pode ser relacionada com a família Smilacaceae, tornando-se o registro mais antigo da família, até então. Cratosmilax jacksoni consiste de uma única folha mesófila com margem inteira, ovada, com ápice e base agudos, quatro ordens de venação e veias principais acródromas. É a primeira monocotiledônea terrestre descrita para a Formação Crato, monocotiledôneas foram anteriormente descritas para a mesma formação, e são consideradas aquáticas. Cratosmilax jacksoni é o primeiro registro fóssil da família Smilacaceae no Brasil, e o registro mais antigo desta família.

The Crato Formation paleoflora is one of the few equatorial floras of the Early Cretaceous. It is diverse, with many angiosperms, especially representatives of the clades magnoliids, monocotyledons and eudicots, which confirms the assumption that angiosperm diversity during the last part of the Early Cretaceous was reasonably high. The morphology of a new fossil monocot is studied and compared to all other Smilacaceae genus, especially in the venation. Cratosmilax jacksoni gen. et sp. nov. can be related to the Smilacaceae family, becoming the oldest record of the family so far. Cratosmilax jacksoni is a single mesophilic leaf with entire margins, ovate shape, with acute apex and base, four venation orders and main acrodromous veins. It is the first terrestrial monocot described for the Crato Formation, monocots were previously described for the same formation, and are considered aquatics. Cratosmilax jacksoni is the first fossil record of Smilacaceae in Brazil, and the oldest record of this family.