First fossil record of Discocephalinae (Insecta, Pentatomidae): a new genus from the middle Eocene of Río Pichileufú, Patagonia, Argentina

Abstract

A new genus and species of Discocephalini, Acanthocephalonotum martinsnetoi gen. n. et sp. n. is described from Río Pichileufú, middle Eocene of Patagonia, Argentina at palaeolatitude ~ 46°S. The new species is the first fossil representative of the Discocephalinae. This taxon is extant in equatorial to subtropical America, and some species reach warm temperate latitudes (Buenos Aires province). The new genus is distinguished from the other genera of Discocephalini by the combination of these characters: interocular width greater than head length; head massive and quadrangular with the anterior margin almost straight; juga touching each other; labrum thick and curved; triangular ante-ocular process extending beyond the eye; broad spine-like antero-lateral process of the pronotum; pronotum explanate and bean shaped; scutellum triangular with a circular tongue reaching the anterior side of abdominal segment 7; and wings well developed with membrane just surpassing end of abdomen.

The Cephalozygoptera, a new, extinct suborder of Odonata with new taxa from the early Eocene Okanagan Highlands, western North America

“…Primorilestes madseni is redrawn from Rust et al (2008, their Subsequent definitions of Dysagrionidae. Some or all of the above genera and sometimes Thaumatoneura, Eodysagrion Rust et al, and others have been grouped in various family configurations, including in the Agrionidae, Amphipterygidae, Pseudolestidae, Megapodagrionidae, as subfamilies of Thaumatoneuridae (Dysagrioninae and Thaumatoneurinae: e.g., Bechly 1996;Nel et al 2005aNel et al , 2005bNel & Arillo 2006), or of the Dysagrionidae (Dysagrioninae, Thaumatoneurinae and Eodysagrioninae: Rust et al 2008;Dysagrioninae, Burmadysagrioninae and Eodysagrioninae: Zheng et al 2016a, 2016b, 2017and independent of Thaumatoneura and Eodysagrion: Garrouste & Nel 2015;Nel et al 2016;Huang et al 2017). Bechly (1996) distinguished the taxon as Dysagrioninae (within Thaumatoneuridae: Dysagrion, Petrolestes, Phenacolestes and Congqingia) by quadrangle shape as its single defining trait, although he did not describe this, and noted that it is also present in Sieblosiidae.…”

“…12C, D). They are considered by some authors not to belong to the Zygoptera by their curved CuP (Petrulevičius & Nel 2003, 2007Petrulevičius 2017Petrulevičius , 2019. The wing of Treintamilun vuelvenlucha Petrulevičius resembles those of the Dysagrionidae in many aspects, but differs by its vertical subnodus and-importantly-its curved CuP.…”

“…There is no Cenozoic fossil record of the Anisozygoptera (the larva Gasophlebia taianensis Lin from the Paleogene of China described by Lin (1982) as an anisozygopteran was considered by more likely a zygopteran). Pseudostenolestes bechlyi Garrouste & Nel from the Lutetian of Messel, Germany was assigned to the Anisozygoptera+Anisoptera stem group Isophlebioptera (Garrouste & Nel 2015) and the Eocene Frenguelliidae of Argentina (four species of three genera: Petrulevičius & Nel 2003, 2007Petrulevičius 2017Petrulevičius , 2019 was considered (stem) Anisozygoptera+Anisoptera, suborder indet. The Oligocene and Miocene Sieblosiidae, with numerous species from Eurasia, have been discussed by various authors (references in discussion below) as odonates belonging to either the Zygoptera or in an undetermined position outside of it.…”

Geometric morphometrics of endophytic oviposition traces of Odonata (Eocene, Argentina)

“…According to Hellmund & Hellmund [ 52 , 53 ], in the fossil record Lestidae females lay their eggs in specific substrates such as Daphnogene leaves (Lauraceae), while Coenagrionidae females do not appear to be selective. Caution must be exercised in assigning substrates to recent families for ovipositions in the Eocene as there are extinct families of Odonata [ 30 ], like Frenguelliidae, Austroperilestidae and Burmagomphidae in Laguna del Hunco and Río Pichileufú [ 31 , 32 , 34 , 37 ] that could be also the producers [ 30 ]. Concerning a more reliable attribution of ovipositions to a certain genus or family of plants, in our studies, it is difficult to assign a preference for substrate because most plant taxa were represented by one or a few samples.…”

A New Malachite Damselfly (Synlestidae: Odonata) from the Eocene of Patagonia, Argentina

“…The locality is renowned for its very high plant diversity (Wilf et al 2005;Wilf 2012). Previously reported insects from the same site are the myrmecine ant Archimyrmex piatnitzkyi (Viana and Haedo Rossi, 1957) (Dlussky and Perfilieva 2003), and the pentatomoid bug Acanthocephalonotum martinsnetoi Petrulevičius and Popov, 2014. Patagonian Eocene localities are exponentially increasing their known plant and insect diversity in recent years through sustained efforts to collect and describe their fossils (Petrulevičius 2001(Petrulevičius , 2009(Petrulevičius , 2013(Petrulevičius , 2015(Petrulevičius , 2016(Petrulevičius , 2017aWilf et al 2003Wilf et al , 2005Petrulevičius and Nel 2005;Petrulevičius et al 2010;Wilf 2012;Petrulevičius and Popov 2014).…”