A fossorial petalurid trace fossil from the Albian of Patagonia

GENISE, JORGE F.; SÁNCHEZ, M. VICTORIA; POIRÉ, DANIEL G.; GONZÁLEZ, MIRTA G.

CRETACEOUS RESEARCH (PRINT)

ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD

Año: 2020

0195-6671

Maichnus wetkaroae igen. isp. nov., from the Albian of Patagonia, is composed of twoor three ellipsoidal oblate chambers connected to shafts that show swellings andconcentrically laminated linings. Such laminated linings are also present in chambers,and probably originated by radial backfilling and/or the successive discharges of liquidorganic excretions. This unique morphology occurs in paleosols showing evidence ofwaterlogging. Trace fossil morphology and the occurrence of traces in clusters inwaterlogged soils indicate that M. wetkaroae igen. isp. nov. represents larval burrowsof fossorial petalurids. This is the first record of Odonatan trace fossils from paleosolsand also the oldest one. M. wetkaroae igen. isp. nov. is one of the oldest insect tracefossils recorded from paleosols. It represents the first and unique paleontologicalevidence of the ancient origin of the burrowing behavior of petalurids postulated onlytheoretically until now in evolutionary scenarios of Odonata.