Odonatan endophytic oviposition from the Eocene of Patagonia: The ichnogenusPaleoovoidusand implications for behavioral stasis

Abstract

ABSTRACT-We document evidence of endophytic oviposition on fossil compression/impression leaves from the early Eocene Laguna del Hunco and middle Eocene Río Pichileufú floras of Patagonia, Argentina. Based on distinctive morphologies and damage patterns of elongate, ovoid, lens-, or teardrop-shaped scars in the leaves, we assign this insect damage to the ichnogenus Paleoovoidus, consisting of an existing ichnospecies, P. rectus, and two new ichnospecies, P. arcuatum and P. bifurcatus. In P. rectus, the scars are characteristically arranged in linear rows along the midvein; in P. bifurcatus, scars are distributed in double rows along the midvein and parallel to secondary veins; and in P. arcuatum, scars are deployed in rectilinear and arcuate rows. In some cases, the narrow, angulate end of individual scars bear a darkened region encompassing a circular hole or similar feature indicating ovipositor tissue penetration. A comparison to the structure and surface pattern of modern ovipositional damage on dicotyledonous leaves suggests considerable similarity to certain zygopteran Odonata. Specifically, members of the Lestidae probably produced P. rectus and P. bifurcatus, whereas species of Coenagrionidae were responsible for P. arcuatum. Both Patagonian localities represent an elevated diversity of potential fern, gymnosperm, and especially angiosperm hosts, the targets of all observed oviposition. However, we did not detect targeting of particular plant families. Our results indicate behavioral stasis for the three ovipositional patterns for at least 50 million years. Nevertheless, synonymy of these oviposition patterns with midMesozoic ichnospecies indicates older origins for these distinctive modes of oviposition.

Phytophagy on fossil ferns from Argentina (Palo Pintado Formation, Late Miocene): a review of their fossil record and ichnotaxonomy

“…The fossil record of insect-plant interactions in angiosperm leaves is more abundant than Paleozoic and Mesozoic records in other host plants. These occurrences come from Chubut (Early Eocene) and Rio Negro (Middle Eocene) provinces (Wilf et al, 2005;Sarzetti et al, 2008Sarzetti et al, , 2009Sarzetti, 2010;Carvalho et al, 2013). More recently, Horn et al (2011) documented insect-mediated damage from the Middle and Upper Miocene from Tucumán and Salta Provinces.…”

“…Until now, the only record known about insect-fern interactions from Argentina, is the one described by Carvalho et al (2013) in the Early Eocene fl ora from Laguna del Hunco, Chubut Province. The ichnotaxonomy of insect trace fossils on leaves was proposed originally by Vialov (1975), which was later used by other authors (Straus, 1977;Givulescu, 1984;Vasilenko, 2005Vasilenko, , 2007aSarzetti et al, 2008Sarzetti et al, , 2009. Most evidence of surface and hole-feeding damage on fossil leaves were described in the literature but without a formal ichnotaxonomic analysis (Ash, 1997;Zherikhin, 2002;Labandeira, 2002b;Banerji, 2004;Prevec et al, 2009;Srivastava & Agnihotri, 2011).…”

The record of Australian Jurassic plant–arthropod interactions

“…Numerous fossil traces with similar basic morphology and assorted regular arrangements recorded on a range of host plants have been attributed to this insect group from the Pennsylvanian to Cenozoic (e.g. van Konijnenburg-van Cittert and Schmeißner, 1999; Béthoux et al, 2004;Vasilenko, 2008;Sarzetti et al, 2009;Wappler, 2010;Petrulevičius et al, 2011;Moisan et al, 2012), and similar scars are produced by modern members of this order (Matushkina, 2007).…”

“…leaves illustrated by Popa and Zaharia (2011) from the Hettangian-Sinemurian of Romania. The Romanian forms, attributed to the ichnospecies Paleoovoidus rectus (Vasilenko) Sarzetti et al, 2009, are similarly elliptical or spindle-shaped scars, 2-3 mm long, 1-1.5 mm wide, and arranged in groups of 2-3 parallel marks. However, the Romanian forms differ in that the scars are distributed in two rows on each side of the rachis.…”

New records of leaf galls and arthropod oviposition scars in Permian - Triassic Gondwanan gymnosperms

“…(Cucadellidae: Hemiptera). Oviposition scars with broadly similar arrangement from the Paleogene and attributed to the ichnogenus Paleoovoidus (Sarzetti et al 2009: fig. 2.3) were probably produced by members of the Zygoptera (Odonata).…”