Research Article |
Corresponding author: Royce T. Cumming ( roycecumming@gmail.com ) Academic editor: Chen‑Yang Cai
© 2024 Royce T. Cumming, Julia J. Mlynarek.
This is an open access article distributed under the terms of the CC0 Public Domain Dedication.
Citation:
Cumming RT, Mlynarek JJ (2024) An additional ✝Archearadinae flat-bug species from Cretaceous Burmese Amber (Hemiptera, Aradidae). ZooKeys 1219: 123-133. https://doi.org/10.3897/zookeys.1219.137409
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Currently 19 species of Aradidae (flat bugs) are known from the Cretaceous deposits of Burma (Burmese/Kachin amber). In reviewing unidentified aradid species from this deposit, an unnamed species was located. This aradid includes a unique combination of features from several Cretaceous aradid genera coupled with apomorphic antennae morphology allows easy differentiation from other aradids. Therefore, a new genus and species is herein described as Sauronaradus meganae gen. et. sp. nov. to accommodate these unique features.
Burma, Cenomanian, extinct, Heteroptera, Myanmar, new species, Pentatomomorpha
The Aradidae is a cosmopolitan family of true bugs with more than 2000 described species in 8 subfamilies and 230 genera (
Species of Aradidae are somewhat prevalent in the fossil record. Thirty-nine extinct species have been described from various fossil deposits from the Cretaceous to the present. Deposits include middle-late Eocene Baltic amber (
Kachin amber (found in the Hukawng Basin of Kachin State in northern Myanmar) dates from the mid-Cretaceous around 100 million years ago (
We describe an additional new genus and species in this remarkable family of true bugs belonging to the extinct subfamily ✝Archearadinae from Kachin amber.
The amber containing the holotype specimen is from the well-known Hukawng Valley in northern Myanmar, a prolific site of amber excavation (
Aradidae head morphology terminology follows
Archearadus burmensis Heiss & Grimaldi, 2001
Archearadus elongatus Heiss, 2016
Archemezira nuoxichenae Heiss & Chen, 2023
Archemezira nuoyichenae Heiss & Chen, 2023
Cretopiesma anticum (Heiss & Poinar, 2012)
Cretopiesma engelgrimaldii Azar, Heiss & Huang, 2020
Cretopiesma inexpectatum Azar, Heiss & Huang, 2020
Cretopiesma lini Azar, Heiss & Huang, 2020
Cretopiesma suukyiae Grimaldi & Engel, 2008
Cretozemira elongata Heiss, 2023
Sauronaradus meganae gen. et. sp. nov.*
Myanmezira longicornis Heiss & Poinar, 2012
Calisiomorpha yuripopovi Heiss, 2016*
Calisiomorpha herczeki Heiss, 2023
Archecalisius longiventris Heiss, 2019
Aradoleptus birmanus Heiss, 2016
Ellenbergeria oviventris Heiss, 2016
Kachinocoris brevipennis Heiss, 2012
Pachytylaradus cretaceous Heiss, 2022
Archeaneurus neli Heiss, 2019
Order Hemiptera Linnaeus, 1758
Suborder Heteroptera Latreille, 1810
Infraorder Pentatomomorpha Leston, Pendergrast & Southwood, 1954
Family Aradidae Brullé, 1836
Subfamily ✝Archearadinae Heiss & Grimaldi, 2002 (tentatively placed)
Sauronaradus meganae gen. et sp. nov., herein designated.
Generic name derived from the epic fantasy novels “The Lord of the Rings” by J. R. R. Tolkien (1892–1973). Both authors independently, upon seeing the spines and armor-like habitus of this species, thought of the armored cinematic depiction of the villainous protagonist Sauron during the “War of the Last Alliance” during the “late Second Age”. The name Sauron ([ˈsaʊron] or [ˈθaʊron], is from the language “Quenya” [one of the languages spoken by the High Elves of Middle-earth]), and he is the eponymous “Lord of the Rings”. The eponym is coupled with árados (Greek: ἄρᾰδος), which is Latinized as “aradus”, referencing the relationship to Aradidae. Gender is masculine following -aradus.
Distinguished from all known extant and extinct Aradidae by various features of the exceptionally long and thin antennae. Typically, aradid antennae are stockier and short, with antennomere lengths only 2×–10× the width, but in Sauronaradus gen. nov. antennomeres II, III, and IV have lengths ~20–22× their widths (Fig.
Macropterous, medium body size ~5 mm (from the apex of the clypeus to the apex of the abdomen); body flat, lateral margins prominently marked with tubercles (with the pronotum margins with three large spiniform tubercles on each side ranging in length from 0.10–0.15 mm long; abdominal margins with granulation and minor tubercles); coloration dark brown.
Head. Longer than wide, clypeus prominent and boxy, with two clearly defined widths, broad for the first half, then half as wide on the apex; antennae exceptionally long and thin with antennomere lengths ~20× the segment widths, segments II–IV of about equal length. Compound eyes large and bulging. Vertex of head with four spiniform tubercles transversing the compound eyes.
Pronotum. A rounded isosceles trapezoid with three distinct widths from the anterior to the posterior. Lateral margin with three large spiniform tubercles. Surface marked throughout by small divots and four longitudinal carinae (the two in the center are more prominent and run the full length of the pronotum while the exterior carinae are less pronounced, only prominent on the posterior half).
Scutellum. Rounded triangular, with the base width ca. equal to the length; surface flat without carinae, just slight granulation/divots.
Legs. Armed with small granulation throughout (more prominent on femora, less so on the tibiae, with some of the more prominent nodes of the femora including a singular seta). Femora thicker than tibiae. Tibiae with dense, thick setae on the apical ends ventral surface. Tarsi two-segmented, claws with lemniscate pulvilli.
Abdomen. Macropterous, but wing details are not discernable in the holotype. Only slightly wider than the thorax, with lateral margins that are subparallel; segments with weakly undulating margins creating three to five lumps with the posterior-most the most prominent and the others of a similar smaller size.
This new genus is tentatively placed in the subfamily ✝Archearadinae Heiss & Grimaldi, 2002. This subfamily lacks an apomorphic character that easily defines it, but instead has been defined by a set of characters from several extant subfamilies, which are held in a unique combination in the ✝Archearadinae. The features present in Sauronaradus gen. nov. which are known from the ✝Archearadinae are: clypeus long and prominent, open rostral atrium arising between the compound eyes not at the apex of the clypeus, abdominal tergites III and VI not fused but instead separated by a distinct suture, and the tarsi are two-segmented with claws bearing pulvilli. This tentative subfamilial placement is also supported by the morphological features shared between Sauronaradus gen. nov. and the genera Archemezira and Archearadus.
Holotype : specimen number IMQC-AMB-ara0001; Hukawng Valley, Myanmar, accession c. 2010; male; specimen deposited within the Montreal Insectarium, Montreal, Quebec, Canada (IMQC).
Ovular piece of clear amber (~15.5 × 10.9 mm), with minimal debris obscuring the holotype (Fig.
Sauronaradus meganae gen. et sp. nov. holotype A anterior lit to highlight the spines of the head, dorsal B head through thorax, dorsal C pronotum, lit to highlight carinae, dorsal D full amber piece with holotype inclusion and Cretopiesma suukyiae syninclusion to the lower right of Sauronaradus meganae gen. et sp. nov. E head through thorax, ventral F pro- and meso- legs, mesotibia and tarsus visible, dorsal G right metatibia, dorsal.
Latest Albian to lowermost Cenomanian (mid-Cretaceous), Hukawng Valley, northern Myanmar.
Patronym, named to honor Megan Solan, environmental toxicologist and entomologist. The first author wishes to thank Megan for her years of friendship and passion for entomology. Her enthusiasm for research is infectious and a positive driving force in the sciences.
Currently the genus is monotypic. See the above diagnosis of the genus for differentiation of this species from other aradids.
(All measurements are in mm and based on the holotype). Macropterous male; large, 5.05 long, 1.88 wide; body flattened (Figs
Head
1.16 long, 0.89 wide (across the compound eyes); dorsally and ventrally rough textured. Compound eyes strongly protruding (Fig.
Antenna
exceptionally long and thin with antennomeres II, III, and IV with lengths c. 20–22× their widths. Antenna with four antennomeres; basal antennomere (scape) the shortest, antennomere lengths: I: 0.27, II: 0.62, III: 0.70, IV: 0.74; antennomeres II, III, and IV tubiform; antennomeres II and III with surface granulation, and antennomere IV densely marked with setae throughout the surface with the seta length slightly less than the antennomere width, with the seta strongly angled apically (Fig.
Thorax
pronotum (0.99 mm long, greatest width 1.44); roughly trapezoidal in shape (increasing in width caudally) but with somewhat undulating margins (approximate widths from the anterior to the posterior: 0.42 mm, 0.99 mm, 1.44 mm, 1.24 mm; Fig.
Legs
long and thin, all with slightly granular surfaces. Profemora 0.90 mm long, thinner on the proximal third. Leg lengths: protibiae 0.75 mm, mesofemora 0.92 mm, mesotibiae 0.60 mm, metafemora 1.16 mm, metatibiae 0.93 mm. Tibiae with sparse setae throughout, with longer and thicker setae on the distal ends (Fig.
Wings fully developed, but details are indiscernible due to taphonomy of the holotype.
Abdomen
broad and flat, all surfaces punctate; length 2.41, greatest width 1.88 mm. Abdominal segment lengths: III = 0.57 mm, IV = 0.34 mm, V = 0.32 mm, VI = 0.37 mm, VII = 0.43 mm, VIII = 0.40 mm. Each abdominal segment has margins which gently undulate, with four or five humps, the posterior-most of which is on the posterior margin and larger than the others (Fig.
Following this description of a new species, there are now 20 Aradidae species described from Cretaceous Kachin amber. Nine of the species have been described since 2020 suggesting that, even though this group is rarely found, it may have been diverse in the mid-Cretaceous, and we are only now beginning to understand this diversity. The morphological uniqueness of the species also demonstrates how little we know about the mid-Cretaceous flat-bug fauna.
The authors have declared that no competing interests exist.
No ethical statement was reported.
No funding was reported.
Both authors have contributed equally.
Royce T. Cumming https://orcid.org/0000-0001-7930-1292
Julia J. Mlynarek https://orcid.org/0000-0002-1569-9403
All of the data that support the findings of this study are available in the main text