Research Article |
Corresponding author: Hiroshi Nakamine ( nakamine.konchu@osaka.email.ne.jp ) Academic editor: Shaun Winterton
© 2018 Hiroshi Nakamine, Shuhei Yamamoto.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Nakamine H, Yamamoto S (2018) A new genus and species of thorny lacewing (Neuroptera: Rhachiberothidae) from Upper Cretaceous Kuji amber. ZooKeys 802: 109-120. https://doi.org/10.3897/zookeys.802.28754
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Kujiberotha teruyukii gen. et sp. n., a remarkable new genus and species of Rhachiberothidae, is described from Upper Cretaceous amber from the Kuji area in northeastern Japan. This discovery represents the first record of this family both from Japan and from East Asia. This fossil taxon has the largest foreleg in the subfamily Paraberothinae found to date and its discovery implies that this group had higher morphological diversity in the Cretaceous than it does now. This finding also stresses the importance of the insect inclusions in Kuji amber, which have not been well explored in spite of their potential abundance.
fossil, Japan, Mantispoidea , Paraberothinae , Rhachiberothidae , Santonian
Rhachiberothidae, or thorny lacewings, are a small family of Neuroptera, which have 13 extant species assigned to three genera as well as rather abundant fossil records and extinct taxa (Table
Rhachiberothidae comprises two subfamilies, Rhachiberothinae and Paraberothinae. Rhachiberothinae includes 13 extant species and two extinct species from mid-Eocene Baltic amber (
Fossil rhachiberothid has never been found from Japan or anywhere else in East Asia. Recently, we examined a rhachiberothid fossil, previously considered as a member of Mantodea (
Taxon | Deposit | Reference |
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Paraberothinae | ||
Chimerhachiberotha acrasarii Nel et al., 2005 | Neocomian, Lebanese amber |
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Paraberotha acra Whalley, 1980 | Neocomian, Lebanese amber |
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Raptorapax terribilissima Petrulevičius et al., 2010 | Neocomian, Lebanese amber |
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Spinoberotha mickaelacrai Nel et al., 2005 | Neocomian, Lebanese amber |
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Alboberotha petrulevicii Nel et al., 2005 | late Albian, Charentese amber (France) |
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Creagroparaberotha groehni Makarkin, 2015 | earliest Cenomanian, Burmese amber |
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Eorhachiberotha burmitica Engel, 2004 | earliest Cenomanian, Burmese amber |
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Paraberothinae sp.: Engel, 2004 | earliest Cenomanian, Burmese amber |
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Micromantispa
cristata
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earliest Cenomanian, Burmese amber |
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Scoloberotha necatrix Engel & Grimaldi, 2008 | earliest Cenomanian, Burmese amber |
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Retinoberotha stuermeri Schlüter, 1978 | early Cenomanian, Bezonnais amber (France) |
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Rhachibermissa phenax Engel & Grimaldi, 2008 | Turonian, New Jersey amber |
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Rhachibermissa splendida Grimaldi, 2000 | Turonian, New Jersey amber |
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Kujiberotha teruyukii gen. et sp. n. | middle Santonian, Kuji amber | this study |
Albertoberotha leuckorum McKellar & Engel, 2009 | Campanian, Canadian amber |
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Rhachiberothinae | ||
Whalfera venatrix (Whalley, 1983) | mid-Eocene, “British” amber* |
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Whalfera wiszniewskii Makarkin & Kupryjanowicz, 2010 | mid-Eocene, Baltic amber |
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subfamily incertae sedis | ||
Oisea celinea (Nel et al., 2005) | earliest Eocene, Oise amber |
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The specimen described in this study was found in the Kuji City, Iwate Prefecture, northeastern Japan (Fig.
The specimen is embedded in a piece of elongated oval amber (18.6 × 8.6 × 4.7 mm) with some bubbles, debris, and deep cracks, covered with opaque substance and therefore only partly visible (Fig.
We observed the specimen using a stereomicroscope SMZ745T and SMZ800 (Nikon corporation, Tokyo, Japan). The photographic data of the specimen was taken with the systems: Canon EOS 80D (Canon Inc., Tokyo, Japan) with EF–S 60mm F2.8 Macro USM (Canon Inc., Tokyo, Japan) plus Kenko Extension Tubes (KenkoTokina Co., Tokyo, Japan). Line drawings were prepared by using Adobe Photoshop CC 2018 and Adobe Illustrator CC 2018.
The terminology of wing venations generally follows
Kujiberotha teruyukii sp. n.
The new genus name is a combination of Kuji City (type locality of this specimen) and the generic name Berotha. Gender feminine.
Antennae moniliform, with at least 50 flagellomeres; forelegs raptorial, profemur long (ca. 1.9 mm), protibia covered with dense fine setae becoming slightly longer towards distal on dorsal edge, together with at least six short spines on ventral edge, probasitarsus with nine small spine-like setae on external ventral ridge; wings with fine setae densely on surface of each vein.
Kujiberotha gen. n. can be distinguished from the six paraberothine genera (Paraberotha, Raptorapax, Creagroparaberotha, Eorhachiberotha, Rhachibermissa, and Albertoberotha) by having much larger number of the flagellomeres of the antenna (Kujiberotha has over 50 antennal flagellomeres, while these genera have only 20–32 ones). From Alboberotha and Micromantispa, our new genus can be separated by having greater number of the spine-like setae on the probasitarsus (Kujiberotha has 9 setae on the probasitarsus, but there are only two such setae in Alboberotha and Micromantispa). Kujiberotha can be further discriminated from Scoloberotha, Spinoberotha, and Chimerhachiberotha based on the numbers of spines on the protibia (Kujiberotha has at least six spines, whereas Scoloberotha has only three; Spinoberotha has numerous sharp spines on the inner edge disposed in two rows; and, those of Chimerhachiberotha are comprised of numerous short setae). Furthermore, the probasitarsus of Kujiberotha is not distinctly elongated, while that of Scoloberotha is markedly elongated, even longer than the combined length of succeeding tarsomeres. Finally, Kujiberotha can be separated from Retinoberotha by the structure of the profemora. Namely, Kujiberotha has at least six long spines and numerous short spines on the ventral edge of the profemora; however, Retinoberotha alternatively has seven short, thin spines or fine setae on the inner lateral edge and they are restricted to the median area of the protibia (
When this fossil was originally excavated in 2006 by Mr Kazuhisa Sasaki (the former director of the Kuji Amber Museum), it was identified as a member of the order Mantodea and this assignment has been believed to be correct until our study. In a recent summary of the fossil records of Mantodea (
Holotype, incomplete specimen of adult, sex undetermined, deposited in the Kuji Amber Museum, Kuji City, Iwate Prefecture, Japan. This specimen is visible only in lateral view and many of the body parts are originally lost or difficult to observe.
Kuji amber from the Kokujicho, Kuji City, Iwate Prefecture, northeastern Japan; Tamagawa Formation of the Kuji Group, middle Santonian (ca. 85.9 Ma; see
This remarkable mantispid-like insect is named in honor of the celebrated kabuki actor Mr. Teruyuki Kagawa. He is known for his love of mantises and is enormously popular with insect-loving children in Japan.
As for the genus (vide supra).
Head entirely not clearly visible due to numerous cracks. Compound eyes partially visible. Antennae (Fig.
The profemur of Kujiberotha teruyukii gen. et sp. n. is the longest among the Paraberothinae fossils found to date. The length of the profemur in this subfamily ranges from ca. 0.5 mm in Spinoberotha mickaelacrai Nel et al., 2005 to ca. 1.14 mm in Raptorapax terribilissima Petrulevičius et al., 2010. Meanwhile, that of K. teruyukii is notably longer, ca. 1.9 mm.
Kujiberotha gen. n. represents the first discovery of Rhachiberothidae from Japan and from East Asia, providing key insights into the past distribution and morphological diversity of thorny lacewings. In fact, the distribution of modern rhachiberothids is limited biogeographically to sub-Saharan Africa (
With 15 fossil genera, including Kujiberotha gen. n., Rhachiberothidae clearly possessed much greater generic diversity in the past than it does now. Indeed, the modern rhachiberothids are composed of only three genera. The discovery of Kujiberotha gen. n. adds further evidence for the potentially higher diversity of Rhachiberothidae during the Cretaceous. It seems reasonable to conclude that the remarkable morphological traits among the Cretaceous paraberothines were more diverse than those of other extinct and extant Rhachiberothidae (e.g., numerous long spines on the inner edge of the protibia, whereas all other rhachiberothids bear no spines). As mentioned above, the structures of the foreleg, particularly the presence of nine small spine-like setae on the external ventral ridge of the probasitarsus, have never before been reported from this family. Furthermore, the markedly large profemur of Kujiberotha gen. n. is quite unexpected and noteworthy. By contrast, some insects from Upper Cretaceous Burmese amber are miniaturized compared to modern taxa; for example, Nicrophorus and Colon beetles from this amber deposit are much smaller than their recent counterparts (
Kuji amber, with its long mining history, is the largest amber deposit in Japan. In spite of its importance, few studies have explored its insect inclusions (e.g.,
We thank Mr Hisao Shinden and Mr Yoshiro Kawatomichi (Kuji Kohaku Co, Ltd., Kuji City, Iwate, Japan) for helping to research the specimen. We sincerely thank Mr Ryo Sato (Kankyo Kagaku Osaka Co., Ltd., Toyonaka City, Osaka, Japan), Mr Satoshi Shimizu and Ms. Hiroko Yamamoto (Minoh Park Insect Museum, Minoh City, Osaka, Japan), and Mr Seidai Nagashima (Itami City Museum of Insects, Itami City, Hyogo, Japan) for the support throughout the course of this study. We are also grateful to Dr Rikio Matsumoto (Osaka Museum of Natural History, Osaka City, Osaka, Japan) for providing an important reference. The second author (SY) was supported by a JSPS (Japan Society for the Promotion of Science, Tokyo, Japan) Overseas Research Fellowship (29-212).