ISOLATED AMBER DROPS AND AMBER BODIES IN LEAVES FROM THE CRETACEOUS OF PATAGONIA

PETRULEVICIUS JULIÁN; ARI IGLESIAS

London

Congreso; 1° Palaentological Virtual Congress; 2018

The Palaeontological Association

The aim of the communication is to denote the incipient and promising presence of the first amberrecord from the Mesozoic of Patagonia. To describe leaf amber bodies and isolated amber tiny drops and to question about the difficulty to find Mesozoic ambers in the southern part of SouthAmerica. Mata Amarilla Formation crops out in Santa Cruz Province and is middle Cenomanian inage. Among a diverse gymnosperm and angiosperm leaf flora, three angiosperm leaf species (Lauraceae, Magnoliaceae, and Bignoniaceae) were found preserving dense fluorescent idioblastsinside the mesophyll. There are ≈ 40 µm amber-coloured bodies, sometimes intracellular andothers in greater glomerules (100 µm). These bodies could be interpreted as the fossilized resiniferous (nonvolatile) fraction of cell contents. On the other hand, we found isolated amberdrops, rounded, about 2 mm diameter, light yellow and translucent, included within layers ofsedimentary rocks associated to rich plant debris. Both leaves and resin drops are not directly associated but in the same fossiliferous layers. There are also insects and insect damages on leaves,including endophytic ovipositions of Odonata, recorded in the same layers. The presence of amberand fluorescent bodies in these Patagonian leaves is promissory for the potential discovery not only of bioinclusions but also of the resin-producing tree taxon.