Research 86 (2018) 53e59

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Cretaceous Research

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Short communication New (Coleoptera) from the Lower Cretaceous , western Liaoning Province, China: Elucidating the systematics of Mesozoic Hybosoridae

** Yuanyuan Lu a, b, 1, Ruie Nie a, 1, Chungkun Shih c, d, Dong Ren c, , Xingke Yang a, * Ming Bai a, a Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, 92 Box, No. 1 Beichen West Road, Chaoyang District, Beijing, 100101, China b University of Chinese Academy of Sciences, Yuquan Road, Shijingshan District, Beijing, 100049, China c College of Life Sciences, Capital Normal University, Beijing, 100048, China d Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013-7012, USA article info abstract

Article history: Two new genera are created to accommodate two new Hybosoridae (Coleoptera: Scarabaeoidea) species: Received 18 September 2017 Sinohybosorus cheni gen. et sp. n. and Sinochaetodus tridentatus gen. et sp. n.. The new species are Received in revised form described and illustrated based on two nearly complete fossil specimens from the Lower Cretaceous 2 January 2018 (Barremiane lower ) Yixian Formation of western Liaoning Province, China. A key of described Accepted in revised form 6 February 2018 species of Hybosoridae from the Mesozoic and a catalog of extinct Hybosoridae are provided. Based on Available online 7 February 2018 the morphological characters, Fortishybosorus ericeusicus Yan, Bai et Ren, 2013 is transferred back to Fortishybosorus instead of Lithohypna in Glaphyridae. The discovery and description of these two new Keywords: fi Fossil taxa provide further evidence for the and Cretaceous diversi cation of lineages of Hybosoridae. Yixian Formation Although the extant Hybosoridae constitute a relative small group in Scarabaeoidea, Hybosoridae are a Sinohybosorus relatively old group of scarab with relative high diversity in the Mesozoic. Sinochaetodus © 2018 Elsevier Ltd. All rights reserved. China New genus

1. Introduction information: Appendix B, including 24 fossil species belonging to 18 genera (three extant genera and 15 fossil genera) (Krell, 2000, The Hybosoridae, a cosmopolitan family of Scarabaeoidea, are 2006, 2007; Ocampo & Ballerio, 2006; Ocampo, 2006a, 2006b; very diverse in the tropics. However, some researchers consider the Nikolajev, 2007a, 2007b, 2008, 2010a, 2010b; Nikolajev et al., group as a subfamily of the family 2010, 2012; Kirejtshuk et al., 2011; Yan et al., 2012; Bai et al., 2016). (Allsopp, 1984; Martínez, 1994). We follow Gardner (1935), Paulian The Hybosoridae are a diversity group of relatively small (1939), Lawrence & Newton (1995), Jameson (2002), and Bouchard scarabs. The antenna has nine to ten antennomeres, with a three- et al. (2011) and consider the group as a family. The Hybosoridae segmented club. Some species, particularly in the Australian comprise six subfamilies (five extant subfamilies and one fossil genus Liparochrous Erichson, 1848 and those of the subfamily subfamily) with more than 550 described extant species. In recent , are capable of rolling up their body to form a years, a number of fossil species belonging to Hybosoridae have compact ball. Larvae are known for only several species, and they been described. A catalog of extinct Hybosoridae are provided in were collected in decomposed plant material or under bark. Larvae supplementary information: Appendix A. Additionally, we sum- and adults of some species are known to stridulate (Ocampo, marize a list of the known fossil hybosorids in supplementary 2006a). Recently, we collected two well-preserved fossil scarab beetles from the Yixian Formation of the Lower Cretaceous in Chaomidian * Corresponding author. Village, City of Beipiao, Liaoning Province (detailed locality see Tang ** Corresponding author. et al., 2015, Fig. 1. Map). The complete preservation of the speci- E-mail addresses: [email protected] (D. Ren), [email protected] (M. Bai). mens enabled us to determine the characters of the body of these 1 Contributed equally. https://doi.org/10.1016/j.cretres.2018.02.005 0195-6671/© 2018 Elsevier Ltd. All rights reserved. 54 Y. Lu et al. / Cretaceous Research 86 (2018) 53e59 ancient scarab beetles. Based on these characters, we describe and in Yixian Age (Ding et al., 2001). Recent studies have confirmed that illustrate two new species belonging to two new Hybosoridae the Yixian Formation belongs to the Lower Cretaceous. The precise genera, Sinohybosorus cheni gen. et sp. n. and Sinochaetodus tri- range is probably 129.7e122.1 Ma ( to early Aptian). dentatus gen. et sp. n.. Their phylogenetic positions are analyzed (Yang et al., 2007) and discussed. The discovery provides further evidence for the Diagnosis. In addition to the diagnosis for the genus, the species can Cretaceous diversification of Hybosoridae. be diagnosed as follows: mesotibia without transverse carinae on outer margin; metatibia with one transverse carinae on outer margin; spurs on the end of tibia prominent, the length of longer 2. Material and methods spur at the end of metatibia 0.58 times as long as metatibia. Description. Body length: 15.1 mm; width: 9.1 mm. Broadly oval, The specimens were examined using a LEICA MZ 12.5 dissecting compact and pilose. microscope and illustrated with the aid of a drawing tube Head. Clypeus finely and closely rugulose, anterior margin straight; attachment. mandible prominent, protruding beyond anterior margin of This study are based on two specimens housed in the fossil in- labrum; maxillary palp three-segmented. Pronotum: Shape para- sect collection of the Key Lab of Evolution & Environmental bolic, 1.9 times as wide as long, notoriously wider than head, widest Changes, the College of Life Sciences, Capital Normal University, near 1/4 to base; anterior margin of pronotum slightly arching, Beijing, China (CNUB; Dong Ren, Curator). lateral sides round; anterior angles are acute, posterior angles Taxon sampling, character states, and a phylogenetic analysis on broadly rounded. Scutellum: Triangular, 1.3 times as wide as long. the phylogenetic positions of the two new genera are provided in Elytron: Shape parabolic, elytra 1.2 times as long as wide medially, supplementary information, Appendix C. 1.1 times as wide as prothorax. Legs: Pro- and mesocoxae close, mesocoxae round; protibia dilated apically, meso- and metatibia 3. Results with long pubes and two spurs at apex; metatibia with one trans- verse carinae on outer margin; mesotibia 2.2 times as long as wide, 3.1. Systematic paleontology metatibia 3.5 times as long as wide; mesotarsal relative length of each segment (base to apex) 6:4:3:6:12. Abdomen: 6-segmented, Order Coleoptera Linnaeus, 1758 apex slightly rounded. Superfamily Scarabaeoidea Latreille, 1802 Genus Sinochaetodus Lu, Bai, Ren and Yang gen. n. Family Hybosoridae Erichson, 1847 (LSIDurn:lsid:zoobank.org:act:8D013AE3-98B4-4250-841A- Genus Sinohybosorus Nie, Bai, Ren and Yang gen. n. B83564AA2B97) (LSIDurn:lsid:zoobank.org:act:44726F8D-77C2-465F-BF50- Type species: Sinochaetodus tridentatus sp. n. 6B0B869AD0EE) Etymology. Sino- (Latin) ¼ from China, Chaetodus is the genus to Type species: Sinohybosorus cheni sp. n. which the new fossil is most similar. Etymology. Sino- (Latin) ¼ from China, is the genus to Diagnosis. Sinochaetodus is similar to Chaetodus Westwood, 1845 which the new fossil is most similar. but differs from the latter by pronotum without areolateocellate, Diagnosis. Sinohybosorus is similar to Hybosorus Macleay, 1819 but meso- and metatibia slender, mesotibia outer margin without differs from the latter by scutellum bigger, the length of elytron longitudinal row of teeth, metatibia outer margin with one longi- 5.3 times as long as scutellum; pronotum widest near 1/4 to base; tudinal row of teeth. Chaetodus has the pronotum with areolateo- legs robust, mesotibia 2.2 times as long as wide, metatibia 3.5 cellate, meso- and metatibia robust, outer margin with two times as long as wide. Hybosorus has the smaller scutellum, the longitudinal rows of teeth. length of elytron at least 15 times as long as scutellum; pronotum widest at base; legs slender, meso- and metatibia at least five Sinochaetodus tridentatus Lu, Bai, Ren and Yang sp. n. (Figs. 3e4) times as long as wide. (LSIDurn:lsid:zoobank.org:act:22E017FB-8CF0-48B8-8BFE- B602BA97D690) Sinohybosorus cheni Nie, Bai, Ren and Yang sp. n. (Figs. 1e2) Holotype. A well preserved almost complete body with elytra, (LSIDurn:lsid:zoobank.org:act:C11EBF53-4724-4F0D-8F6A- registration No. CNU-COL-LB2016002, Yixian Formation, near C83319751D72) Chaomidian Village, Beipiao City, Liaoning Province, China; The Holotype. A well preserved almost complete body with elytra, type specimen is housed in the Key Lab of Insect Evolution & registration No. CNU-COL-LB2016001, Yixian Formation, near Environmental Changes, the College of Life Sciences, Capital Chaomidian Village, Beipiao City, Liaoning Province, China; the type Normal University, Beijing, China (CNUB). specimen is housed in the Key Lab of Insect Evolution & Environ- Etymology. Tridentatus (Latin) ¼ with three teeth, here referring to mental Changes, the College of Life Sciences, Capital Normal Uni- the protibia. versity, Beijing, China (CNUB). Type strata and locality. Same as those of Sinohybosorus cheni Nie, Etymology. The specific epithet is in honor of Academician Prof. Bai, Ren and Yang sp. n. Sicien Chen (Shixiang Chen), the former director of Institute of Diagnosis. In addition to the diagnosis for the genus, the species can Zoology (IOZ), Chinese Academy of Sciences (CAS), Beijing, China. be diagnosed as follows: protibia with three teeth on outer margin, Prof. Chen was the former leader of Group of Morphology and scutellum triangular, preapical surfaces of meso- and metatibia Evolution of Coleoptera, IOZ, CAS, and he has made great contri- without transverse ridges, mesotibia outer margin without longi- butions to the research of from China. tudinal row of teeth, metatibia outer margin with one longitudinal Type strata and locality. The strata of Yixian Formation of Chao- row of teeth. midian Village, western Liaoning of China, mainly of lacustrine Description. Body length: 11.5 mm; width: 5.8 mm. Broadly oval, sediments intercalated with volcaniclastics (Ren et al., 1995, 2010), compact and pilose. are rich in insect fossils. Paleobotanical data from fossil spores, Head. Slightly wider than long, ovate, broadest at eyes; clypeus pollen and plants indicates a climate that was both warm and moist anterior margin slightly round; antennae with three-segmented Y. Lu et al. / Cretaceous Research 86 (2018) 53e59 55

meso- and metatibia slender; preapical surfaces of meso- and metatibia without transverse ridges, mesotibial outer margin without longitudinal row of teeth, metatibial outer margin with one longitudinal row of teeth; mesotarsal relative length of each segment (base to apex) 3:2:2:2:4. Abdomen: six-segmented, apex slightly rounded. 3.2. Catalog and key to Hybosoridae fossils

The Hybosoridae comprise 26 fossil species in 20 fossil genera (including the two new genera) (Appendix A). Among the 26 fossil species, 20 species are from the Mesozoic Era and 6species from the Cenozoic. Five of the 20 Mesozoic species are excluded in the key because of poor preservation of the type specimens, which are Cretohybosorus striatulus Nikolajev (1999), Protohybosorus grandi- ssimus Nikolajev (2010b), Jurahybosorus mongolicus Nikolajev (2005), Libanochrus calvus Kirejtshuk, Azar & Montreuil (2011), Fig. 1. Sinohybosorus cheni gen. et sp. n., holotype No. CNU-COL-LB2016001. Line and Cretanaides trogopterus Nikolajev (1996). Cretohybosorus stria- drawings of (A) ventral view; (B) dorsal view. (Scale:1 mm). tulus does not have preserved head and pronotum. From the description and the photo of Cretohybosorus striatulus, its system- club, first segment not cupuliform; mandible strongly prominent atic position is doubtful. In addition, Protohybosorus grandissimus and significantly wider than clypeus; maxillary palp three- lacks the hind leg, Jurahybosorus mongolicus only has pterothorax, segmented, relative length of each segment (base to apex) 2:1:1. Libanochrus calvus only has head, and Cretanaides trogopterus only Pronotum: Shape parabolic, 2.2 times as wide as long, notoriously has one elytron. Therefore, all five are excluded in the key. We wider than head, widest at base; anterior margin of pronotum found the size of body varies in fossil Hybosoridae from 3.0 to straight, lateral sides round; anterior angles are rounded, posterior longer than 20.0 mm, whereas the size of extant species only from angles broadly rounded. Scutellum: Triangular, 2.3 times as wide as 3.0 to 7.0 mm (Ocampo, 2006a, b). The key not only update species long. Elytron: Shape parabolic; elytra 1.3 times as long as wide reported in recent years, but also correct some mistakes of the key medially, 1.4 times as wide as prothorax, elytron without obvious published in 2013 (Yan et al., 2013). Considering the characters and striae. Legs: Pro- and mesocoxae close; protibia dilated apically, previous key (Yan et al., 2013), we relied more on the figures of with 3 teeth on outer margin; meso- and metatibia with long pu- fossil rather than the text descriptions. bescence and two spurs at apex; spurs differing distinctly in length;

Fig. 2. Habitus of Sinohybosorus cheni gen. et sp. n., holotype No. CNU-COL-LB2016001. Photographs of (A) general habitus; (B) head, red rectangle as located on A; (C) protibia, blue rectangle as located on A; (D) mesotibia, green rectangle as located on A; (E) metatibia, pink rectangle as located on A. (Scale:1 mm). (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.) 56 Y. Lu et al. / Cretaceous Research 86 (2018) 53e59

10 Body oval, less than three times as long as wide...... 2 2(1) Body small (length less than 10 mm)...... 3 20 Body large (length more than 10 mm)...... 8 3(2) Mandibles invisible in dorsal view...... 4 30 Mandibles visible in dorsal view...... 5 4(3) The lateral margins of pronotum are straight Protanaides sibiricus Nikolajev, 2010 40 The lateral margins of pronotum are arcuately convex...... Mimaphodius pusillus Nikolajev, 2007 5(3) Mesotibia with one transverse carinae on outer margin ...... 6 50 Mesotibia without transverse carinae on outer margin...7 6(5) Pronotum narrow and long, lateral margins with densely long hair, posterior margins nearly straight...... Cretohybosorus buryaticus Nikolajev, 1999 60 Pronotum broad and short, lateral margin without hair, posterior margins obviously protruding...... Jurahybosorus kazakhstanicus Nikolajev, 2008 7(5) Pronotum trapeziform, with lateral margins slightly convex, the widest at its base...... 8 Fig. 3. Sinochaetodus tridentatus gen. et sp. n., holotype No. CNU-COL-LB2016002. Line 0 drawings of (A) ventral view; (B) dorsal view. (Scale: 1 mm). 7 Pronotum transverse, with lateral margins convex, the widest at its middle....Leptosorus zherikhini Nikolajev, 2006 Key to species of Hybosoridae from the Mesozoic Era 8(7) Abdomen with six visible sternites...... Fortishybosorus ericeusicus Yan, Bai & Ren 2012 1 Body elongate, about four times as long as wide...... 80 Abdomen with five visible sternites...... Hybosorus ...... Mesoceratocanthus tuberculifrons Nikolajev, Wang, Liu ocampoi Bai & Zhang, 2016 & Zhang, 2010

Fig. 4. Habitus of Sinochaetodus tridentatus gen. et sp. n., holotype No. CNU-COL-LB2016002. Photographs of (A) general habitus; (B) head, red rectangle as located on A; (C) protibia, blue rectangle as located on A; (D) mesotibia, green rectangle as located on A. Red arrow (in A) indicates the margin of elytron; black arrow (in B) indicates the antennae. (Scale: 1 mm). (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.) Y. Lu et al. / Cretaceous Research 86 (2018) 53e59 57

9(2) Metatibia with one transverse carinae on outer margin from the Upper Jurassic (one from Bayan-Teg, Mongolia, one from ...... 10 Chimkent, Kazakstan and one from Myanmar amber) and three 90 Metatibia without transverse carinae on outer margin...12 species from the Middle-Upper Jurassic (Baidibek, Kazakhstan) 10(9) Mesotibia with one transverse carinae on outer margin (Heer, 1847, 1862; Giebel, 1852; Deichmüller, 1881; Krell, 2000, ...... 11 2006, 2007; Ocampo, 2006b; Nikolajev, 2007a, 2007b, 2008, 100 Mesotibia without transverse carinae on outer margin 2010a, 2010b; Nikolajev et al., 2010, 2012; Kirejtshuk et al., ...... Sinohybosorus cheni gen. et sp. n. 2011; Yan et al., 2012; Bai et al., 2016). More detailed informa- 11(10) Body oblong, pronotum transverse, the widest at its tion is listed in the Catalog. The oldest fossil record of the middle...... Protohybosorus karatavicus Nikolajev, 2010 Hybosoridae is from the MiddleeUpper Jurassic (ca. 164.7e155.7 11 0 Body oblong oval, pronotum trapeziform, the widest at its Ma), which is also the oldest fossil record in Scarabaeoidea base...... Protohybosorus mesasiaticus Nikolajev, 2010 (Ahrens et al., 2014). Based on previous results and present study, 12(9) Elytron elongate, more than two times as long as wide....13 we find that although the extant Hybosoridae constitute a relative 120 Elytron oval, less than two times as long as wide...... 14 small group in Scarabaeoidea, Hybosoridae are a relatively old 13(12) Metatibia outer margin with one longitudinal row of group of scarab beetles and there was a relative high diversity of teeth...... Sinochaetodus tridentatus gen. et sp. n. the Hybosoridae in the Mesozoic. 130 Metatibia outer margin without longitudinal row of teeth ...... Pulcherhybosorus tridentatus Yan, Bai & Ren, 2012 4.3. Systematic position of Sinohybosorus cheni gen. et sp. n. and 14(12) Scutellum big, about 1/2 as long as elytron base Sinochaetodus tridentatus gen. et sp. n...... Leptosorus fortus (Ren, Zhu & Lu, 1995) 140 Scutellum small, less than 1/3 as long as elytron base For a reliable identification of a specimen as belonging to the ...... Crassisorus fractus Nikolajev, Wang & Zhang, 2012 Scarabaeoidea, it has to show at least one synapomorphy related to this taxon that ideally should not be reduced in any terminal 4. Discussion subordinated taxon at any period. As only preserved characters are available for fossil specimens, Krell (2000) gave a list of 4.1. Hybosoridae systematics synapomorphies of Scarabaeoidea which were suitable for scarab fossil identification. Sinohybosorus cheni and Sinochaetodus tri- Six subfamilies are currently recognized in Hybosoridae: Anai- dentatus can be classified within the Scarabaeoidea by having dinae, Pachyplecterinae, Ceratocanthinae, Hybosorinae, Lipar- antennae with lamellate club and protibiae with teeth on its ochrinae, and Mimaphodiinae (Ocampo, 2006b; Nikolajev, 2007a). outer margin. Through careful comparison of morphological characters, we found Sinohybosorus cheni gen. et sp. n. can be classified within the first five subfamilies have good support but the position of Hybosoridae according to the following characters: body oblong, Mimaphodiinae is hardly recognized. The diagnostic characters of not capable of being rolled into a contracted sphere; mandibles Mimaphodiinae Nikolajev (2007a) are consistent with those of produced beyond the apex of labrum, thick at base, apex pointed; Pachyplecterinae, and partly consistent with those of Anaidinae mesotibial spur double, metatibial spurs differing distinctly in and Hybosorinae. However, from the description of the type genus length, outer edge of protibia with teeth, six abdominal ventrites, of Mimaphodiinae, Mimaphodius Nikolajev, 2007, we found a sup- mesocoxal cavities round and at the middle contiguous. porting character for Mimaphodiinae: mandibles not exposed Sinohybosorus cheni gen. et sp. n. is at the base of the Hybosor- beyond the apex of clypeus. But this character is hard to discern idae together with the others fossils according our phylogenetic from the drawing as there is minor damage at the anterior part of analysis (Supplementary Figs. 1e2). Sinohybosorus is similar to the specimen. For now, we consider Mimaphodiinae of Hybosor- Hybosorus but there is not enough evidence to place it in the idae is doubtful and new evidence is needed. subfamily Hybosorinae. This fossil genus is more like the ground We have tried to make a phylogenetic tree (see details in plan of the Hybosoridae, which bears many plesiomorphic char- Appendix C: Text C.1-2, Table C.1; Supplementary Fig. 1e2), but it acter states of the Hybosoridae. Sinohybosorus is not in any lineages was not possible to get a good support of the fossil lineages, of extant Hybosoridae (Supplementary Fig. 2) and is sister to probably due to the limited characters in the fossil records. It Sinochaetodus tridentatus, which is considered as incertae sedis. cannot be denied that, to some extent, the classification of some Thus, we consider Sinochaetodus as subfamily incertae sedis. fossils is still doubtful, and more study is needed in the future. Sinochaetodus tridentatus gen. et sp. n. can be classified within Hybosoridae according to the following characters: body oblong, 4.2. Fossil record not capable of being rolled into a contracted sphere; antennae with three-segmented club, the first segment not cupuliform; mandibles The fossils of Scarabaeoidea are mainly from Europe and Asia, produced beyond apex of labrum, thick at base, the apex pointed; and only a few fossils are from Africa and America. The Hybosoridae mesotibial spurs double, metatibial spurs differing distinctly in have one of the relatively most abundant fossil records of the length, outer edge of protibia with teeth, six abdominal ventrites, Scarabaeoidea. Most records are consisted of taxa belonging to the mesocoxal cavities at the middle contiguous. Hybosorinae. No extinct Pachyplecterinae has been described so Sinochaetodus tridentatus gen. et sp. n. is also at the base of the far. Only one fossil species has been recorded of the Ceratocanthi- Hybosoridae together with the others fossils according our phylo- nae (Nikolajev et al., 2010). genetic analysis (Supplementary Figs. 1e2). Sinochaetodus is similar Among 26 species (including the two new species), five species to Chaetodus but we do not have enough evidence to place it in the € are from the (two species from Ohningen, Germany and subfamily Anaidinae, however it can be classified to Anaidinae and three species from Dominican Amber), one species from the Hybosorinae by abdomen with 6 free sternites, and meso- and Eocene (Kuclín [Kutschlin] near Bílina [Bilin], Czech Republic), one metatibia without transverse carinae. This fossil genus is more like species from the Upper Cretaceous (from Myanmar amber), 14 the ground plan of the Hybosoridae, which bears many plesio- species from the Lower Cretaceous (six species from Baysa, Russia, morphic character states of Hybosoridae and some character states four species from Inner Mongolia, China, three from Liaoning of Ochodaeidae. Thus, Sinochaetodus is considered as subfamily Province, China and one from Lebanese amber), three species incertae sedis. 58 Y. Lu et al. / Cretaceous Research 86 (2018) 53e59

4.4. Systematic position of Fortishybosorus ericeusicus Yan, Bai et Giebel, C.G., 1852. Deutschlands Petrefacten. Ein Systematisches Verzeichniss aller € Ren, 2013 in Deutschland und den angrenzenden Landern vorkommenden Petrefacten nebst Angabe der Synonymen und Fundorte. Verlag von Ambrosius Abel, Leipzig. Fortishybosorus ericeusicus Yan, Bai et Ren, 2013 can be classified Heer, O., 1847. Die Insektenfauna der Tertiargebilde€ von Oeningen und von Radoboj € within Hybosoridae based on several characters (Yan et al., 2013). in Croatien. Erste Abtheilung: Kafer. Neue Denkschriften der Allg. Schweizer- ischen Gesellschaft für die Gesammten Naturwissenschaften 8, 1e229 [pub- Nikolajev transferred Fortishybosorus to Lithohypna in Glaphyridae lished separately at Leipzig in the same year]. without a detailed explanation (Nikolajev, 2014). According to a Heer, O., 1862. Beitrage€ zur Insektenfauna Oeningens. Coleoptera. Geodaphagen, previous study, the reason is probably due to this character: py- Hydrocanthariden, Gyriniden, Brachelytren, Clavicornen, Lamellicornen und Buprestiden. Natuurkundige Verhandelingen van de Hollandsche Maatschappij gidium visible beyond elytra (Nikolajev et al., 2011). But in our der Wetenschappen te Haarlem 16, 1e90. opinion, the character of pygidium visible beyond elytra in For- Jameson, M.L., 2002. Chapter 31: Hybosoridae Erichson 1847. In: Arnett, R.H., tishybosorus ericeusicus is probably the result of fossilization. The Thomas, M.C., Skelley, P.E., Frank, J.H. (Eds.), American Beetles, vol. 2. CRC Press, Boca Raton, pp. 32e33. use of only one character to judge the position is not enough. Kirejtshuk, A.G., Azar, D., Montreuil, O., 2011. First Mesozoic representative of the Considering the following characters: body oblong not elongate, subfamily Liparochrinae (Coleoptera: Hybosoridae) from the Lower Cretaceous upper surfaces of body without distinct hairs, setae or scales, pro- Lebanese amber. Zoosystematica Rossica 20, 63e70. notum almost equal to base of elytron, and the lateral margin of Krell, F.T., 2000. The fossil record of Mesozoic and Tertiary Scarabaeoidea (Cole- optera: ). Invertebrate 14, 871e905. elytron convex not subparallel, Fortishybosorus ericeusicus should Krell, F.T., 2006. Fossil record and evolution of Scarabaeoidea (Coleoptera: Poly- belong to Hybosoridae. So Fortishybosorus ericeusicus Yan, Bai et phaga). Coleopterists Society Monograph 5 (Supplement to the Coleopterists e Ren, 2013 has been transferred back to Fortishybosorus instead of Bulletin 60) 120 143. Krell, F.T., 2007. Catalogue of fossil Scarabaeoidea (Coleoptera: Polyphaga) of the Lithohypna in Glaphyridae. Mesozoic and Tertiary - Version 2007. Denver Museum of Nature & Science Technical Report 8, 1e79. Lawrence, J.F., Newton, A.F., 1995. Families and subfamilies of Coleoptera (with 5. Conclusions selected genera, notes, references and data on family-group names). In: Pakaluk, J., Slipinski, S.A. (Eds.), Biology, Phylogeny, and Classification of Cole- Extinct Hybosoridae is reviewed with a key of described species optera: Papers Celebrating the 80th Birthday of Roy A. Crowson. Muzeum i Instytut Zoologii PAN, Warszawa, Poland, pp. 779e1006. of Hybosoridae from the Mesozoic and a catalog of extinct Martínez, A., 1994. Notas sobre Hybosorinae (Coleoptera: Scarabaeidae), II. Elytron Hybosoridae. 8, 223e239. Two new genera and species, Sinohybosorus cheni gen. et sp. n. Nikolajev, G.V., 1996. Vidy plastinchatousykh zhukov (Coleoptera, Scarabaeidae) s bol’shim kolichestvom bopozdok na nadkryl’iakh iz nizhemelovogo mestona- and Sinochaetodus tridentatus gen. et sp. n. from the Lower khozhdeniia Baisa v Zabaikalie. Paleontologicheskii Zhurnal 91e99 [Trans- Cretaceous Yixian Formation, are described to Hybosoridae. lation: Nikolajev, G.V., 1996. Lamellicorn species (Coleoptera, The phylogenetic positions of some hybosorids fossils are still Scarabaeidae) with multistriate elytra from the Lower Cretaceous Baisa locality, Transbaikalia. Paleontological Journal 30, 217e224.]. doubtful. More complete work on the robust phylogeny of Nikolajev, G.V., 1999. Materialy k sistematike plastinchatousykh zhukov podse- Hybosoridae based on fossil evidence are needed in future. meistva Hybosorinae (Coleoptera, Scarabaeidae) s vydeleniem novoi triby dlya The average body size of extinct hybosorids is larger than extant chetyrekh monotipichnykh podov iz Yuzhnoi Ameriki i opistniem novykh taksonov iz nizhnego mela Zabaikal’ya. Tethys Entomological Research 1, ones. Hybosoridae are a relatively old group of scarab beetles 173e182. with relative high diversity in the Mesozoic. Nikolajev, G.V., 2005. Novyy rod triby Hybosorini (Coleoptera, Scarabaeidae) iz mezozoya Azii. Tethys Entomological Research 11, 27e28. Nikolajev, G.V., 2006. A new genus in Hybosorinae (Coleoptera, Scarabaeidae) from Acknowledgments the Lower Cretaceous of Transbaikalia. Euroasian Entomological Journal 5, 12e13. We are grateful to two anonymous reviewers for improvement Nikolajev, G.V., 2007a. Novoe podsemeystvo plastinchatousih zhukov semeystva Hybosoridae (Coleoptera, Scaraboidea) iz Mezozoya Azii. Izvestiya Natsionalnoi of our manuscript. Many thanks to Dr. David Kral, who provided Akademii Nauk Respubliki Kazakhstan Seriya Biologicheskaya i Meditsinskaya some specimens as outgroups in phylogeny analysis. This work was 2, 47e48. supported by the National Natural Science Foundation of China (No. Nikolajev, G.V., 2007b. Mezozoiskii Etap Evolyutsii Plastinchatousykh (Insecta: Coleoptera: Scarabaeoidea). Kazak Universiteti, Almaty. 31672345, 31672323, 41688103), Research Equipment Develop- Nikolajev, G.V., 2008. A new species of the genus Jurahybosorus Nikolajev (Cole- ment Project of Chinese Academy of Sciences (YZ201509), Program optera, Scarabaeoidea: Hybosoridae) from the Upper Jurassic of Kazakhstan. for Changjiang Scholars and Innovative Research Team in Univer- Tethys Entomological Research 16, 27e30. sity (IRT-17R75) and Support Project of High-level Teachers in Nikolajev, G.V., 2010a. Novyy rod podsemeystva Anaidinae (Coleoptera: Scar- abaeoidea: Hybosoridae) iz mezozoya Zabaykaliya. Paleontologicheskii Zhurnal Beijing Municipal Universities (IDHT20180518). 67e69 [Translation: Nikolajev, G.V., 2010. A new genus of the Subfamily Anai- dinae (Coleoptera, Scarabaeoidea, Hybosoridae) from the Mesozoic of Trans- baikalia. Paleontological Journal 44, 192e194.]. References Nikolajev, G.V., 2010b. O mezozoiskii taksonakh plastinchatousykh zhukov semystva Hybosoridae (Coleoptera: Scarabaeoidea). Paleontologicheskii Zhur- Ahrens, D., Schwarzer, J., Vogler, A.P., 2014. The evolution of scarab beetles tracks nal 49e52 [Translation: On the Mesozoic taxa of Scarabaeoid Beetles of the the sequential rise of angiosperms and mammals. Proceedings of the Royal family Hybosoridae (Coleoptera: Scarabaeoidea). Paleontological journal 44, Society B: Biological Sciences 281, 20141470. 649e653.]. Allsopp, P.G., 1984. Checklist of the Hybosorinae (Coleoptera: Scarabaeidae). The Nikolajev, G.V., 2014. On the position of the fossil species Fortishybosorus ericeusicus Coleopterists Bulletin 38, 105e117. Yan, Bai et Ren, 2012 within the superfamily scarabs (Coleoptera: Scar- Bai, M., Zhang, W.W., Ren, D., Shih, C.K., Yang, X.K., 2016. Hybosorus ocampoi: the abaeoidea). Euroasian Entomological Journal 13 (3), 253e256 (in Russian). first hybosorid from the Cretaceous Myanmar amber (Coleoptera: Scar- Nikolajev, G.V., Wang, B., Liu, Y., Zhang, H.C., 2010. First record of Mesozoic Cera- abaeoidea). Organisms Diversity and Evolution 16, 233e240. tocanthinae (Coleoptera: Hybosoridae). Acta Palaeontologica Sinica 49, Bouchard, P., Bousquet, Y., Davies, A.E., Alonso-Zarazaga, M.A., Lawrence, J.F., 443e447. Lyal, C.H.C., Newton, A.F., Reid, C.A.M., Schmitt, M., Slipinski, S.A., Smith, A.B.T., Nikolajev, G.V., Wang, B., Zhang, H.C., 2011. A new fossil genus of the family Gla- 2011. Family-group names in Coleoptera (Insecta). ZooKeys 88, 1e972. phyridae (Coleoptera: Scarabaeoidea) from the Lower Cretaceous Yixian For- Deichmüller, J.V.,1881. Fossile Insecten aus dem Diatomeenschiefer von Kutschlin bei mation. Zootaxa 2811, 47e52. Bilin, Bohmen.€ Verhandlungen der Kaiserlichen LeopoldinischeCarolinischen Nikolajev, G.V., Wang, B., Zhang, H., 2012. A new genus of the family Hybosoridae Deutschen Akademie der Naturforscher 42, 293e331. (Coleoptera, Scarabaeoidea) from the Yixian Lower Cretaceous Formation in Ding, Q.H., Zhang, L.D., Guo, S.Z., Zhang, C.J., Peng, Y.D., Jia, B., Chen, S.W., Xing, D.H., China. Euroasian Entomological Journal 11 (6), 503e505þ506þIII. 2001. The stratigraphic sequence and fossil-bearing horizon of the Yixian For- Ocampo, F.C., 2006a. 1. Introduction to the scarab family Hybosoridae (Coleoptera: mation in western Liaoning, China. Geology and Resources 10, 193e198 (in Scarabaeoidea). In: Ocampo, F.C. (Ed.), Phylogenetic Analysis of the Scarab Chinese). Family Hybosoridae and Monographic Revision of the New World subfamily Gardner, J.C.M., 1935. Immature stages of Indian Coleoptera (16) (Scarabaeoidea). Anaidinae (Coleoptera: Scarabaeoidea). the University of Nebraska State Indian Forest Records (New Series, Entomology) 1, 1e33. Museum, Lincoln, Nebraska, pp. 3e6. Y. Lu et al. / Cretaceous Research 86 (2018) 53e59 59

Ocampo, F.C., 2006b. 3. Phylogenetic analysis of the New World Subfamily Anai- Tang, D., Yao, Y.Z., Ren, D., 2015. New fossil flower bugs (Heteroptera: Cimicomor- dinae (Coleoptera: Scarabaeoidea). In: Ocampo, F.C. (Ed.), Phylogenetic Analysis pha: Cimicoidea: Vetanthocoridae) with uniquely long ovipositor from the of the Scarab Family Hybosoridae and Monographic Revision of the New World Yixian Formation (Lower Cretaceous), China. Cretaceous Research 56, 504e509. Subfamily Anaidinae (Coleoptera: Scarabaeoidea). the University of Nebraska Yan, Z., Bai, M., Ren, D., 2012. A new fossil Hybosoridae (Coleoptera: Scarabaeoidea) State Museum, Lincoln, Nebraska, pp. 13e177. from the Yixian Formation of China. Zootaxa 3478, 201e204. Ocampo, F.C., Ballerio, A., 2006. 4. Catalog of the subfamilies Anaidinae, Cerato- Yan, Z., Bai, M., Ren, D., 2013. A new genus and species of fossil Hybosoridae canthinae, Hybosorinae, Liparochrinae, and Pachyplectrinae (Scarabaeoidea: (Coleoptera: Scarabaeoidea) from the Early Cretaceous Yixian Formation of Hybosoridae). In: Ocampo, F.C. (Ed.), Phylogenetic analysis of the scarab family Liaoning, China. Alcheringa: An Australasian Journal of Palaeontology 37, Hybosoridae and monographic revision of the New World subfamily Anaidinae 139e145. (Coleoptera: Scarabaeoidea). The University of Nebraska State Museum, Lincoln, Yang, W., Li, S.G., Jiang, B.Y., 2007. New evidence for Cretaceous age of the feathered Nebraska, pp. 178e209. dinosaurs of Liaoning: zircon U-Pb SHRIMP dating of the Yixian Formation in Paulian, R., 1939. Les caracteres larvaires des Geotrupidae (Col.) et leur importance Sihetun, northeast China. Cretaceous Research 28, 177e182. pour la position systematique du groupe. Bulletin de la Societ e Zoologique de France 64, 351e360. Ren, D., Lu, L.W., Ji, S.A., Guo, Z.G., 1995. Faunae and Stratigraphy of Jurassic- Cretaceous in Beijing and the adjacent areas. Seismic Publishing House, Beijing. Appendix A. Supplementary data Ren, D., Shih, C.K., Gao, T.P., Yao, Y.Z., Zhao, Y.Y., 2010. Silent StoriesdInsect Fossil Treasures from Dinosaur Era of the Northeastern China. Science Press, Beijing, Supplementary data related to this article can be found at https://doi.org/10. p. 332. 1016/j.cretres.2018.02.005.