INSTITUTO ARGENTINO DE NIVOLOGIA, GLACIOLOGIA Y CIENCIAS AMBIENTALES
Unidad Ejecutora - UE
congresos y reuniones científicas
First record of insect-plant interactions on aberrant fronds of Dicroidium and Johnstonia (Corystospermaceae) from the Triassic of Mendoza, Argentina.
D`ANGELO J A; PIRRONE C A
Colonia del Sacramento
Simposio; Tercer Simposio Latinoamericano de Icnología, SLIC 2015; 2015
Multiple disc-like galls from abnormal foliage remains of Dicroidium odontopteroides (Morris) Gothan and Johnstonia stelzneriana (Geinitz) Frenguelli are reported for the first time for the Triassic of Mendoza (Argentina). Provenance of corystosperm remains preserved as impressions is Puesto El Durazno locality from the lower Cacheuta Formation. Galls occurring on both the midrib and leaf blade, are circular (2-4 mm diameter); protrude above the leaf surface; contain a distinct, thin, outer wall, and inner contents that are filled with sediment. Aberrant (abnormal) morphology of fronds includes (i) unusual lobate margins in pinnules of D. odontopteroides and (ii) secondary frond dichotomy along with leaf blade with deeply lobed margins in J. stelzneriana specimen. The abnormal growth of foliar specimens in response to the stimulus from the invading organism/s is not ruled out. Also, this new trace fossil record of insect-plant interaction 1) contributes to broaden our knowledge of insects in Triassic continental deposits that lack insect body fossils; 2) provides information about behavior otherwise unavailable from the body-fossil; and 3) offers critical information for testing paleobiological hypothesis in this area. General conclusions of this work report a richer record of plant-animal interactions in the middle to late Triassic of high-latitude Gondwana than previously known.