ABSTRACT
Beetles have a remote evolutionary history dating back to the Carboniferous, with Mesozoic fossils playing a pivotal role in elucidating the early evolution of extant families. Despite their exceptional preservation in amber, deciphering the systematic positions of Mesozoic trogossitid-like beetles remains challenging. Here, we describe and illustrate a new trogossitid-like lineage from mid-Cretaceous Kachin amber, Foveapeltis rutai Li, Kolibác, Liu & Cai, gen. et sp. nov. Foveapeltis stands out within the Cleroidea due to the presence of a significant large cavity on each hypomeron. While the exact phylogenetic placement of Foveapeltis remains uncertain, we offer a discussion on its potential affinity based on our constrained phylogenetic analyses.
ABSTRACT
A new species of the extant staphylinid genus Vicelva Moore & Legner, V. rasilis sp. nov., is reported from mid-Cretaceous Kachin amber of northern Myanmar. Vicelva rasilis is distinguishable from extant members of Vicelva by the smoother dorsal surface of head, pronotum and elytra, less prominent median projection of clypeus, unnotched mesal edge of mandibles, semiglabrous antennomere 6, and longer tarsomere 1. The pollen-containing coprolite attached to the beetle and the crystals within the beetle body provide valuable information about the biology and taphonomy of the fossil.
ABSTRACT
In order to place newly discovered fossil taxa (Palaeosymbius gen. nov. with P. groehni and P. mesozoicus spp. nov.) from the mid-Cretaceous amber from northern Myanmar, we investigated the relations of extant and extinct lineages of the coccinellid group of Coccinelloidea with emphasis on the family Anamorphidae. We assembled a taxonomic sampling of 34 taxa, including 15 genera and 19 species of Anamorphidae, the most comprehensive sampling of Anamorphidae at the generic level in a phylogenetic analysis. A morphological dataset of 47 characters was built as well as a molecular alignment of 7140 bp including fragments of eight genes (12S, 16S, 18S, 28S, COI, COII, H3 and CAD). Five anamorphid and one endomychid species were sequenced for the first time and added to the dataset. We performed parsimony-based analysis of the morphological dataset and Bayesian inference analysis of the combined matrix (morphological plus molecular data). Our results confirm that Palaeosymbius belongs to Anamorphidae and represents the oldest known member of this family so far. Among Anamorphidae, Symbiotes (with extant and known Eocene species) was recovered as the most probable closest relative of Palaeosymbius. Our morphological studies additionally revealed the presence of probable glandular openings in the anterolateral corners of the pronotal margins in Asymbius sp. and Anamorphus sp., representing the first report of secretory openings in the family Anamorphidae. Similar openings are found in other cucujiform beetles such as Cryptophagidae and Boganiidae with possible defensive purposes.
ABSTRACT
The morphology of beetles of the recently defined superfamilies Erotyloidea, Nitiduloidea and Cucujoidea is varied. Determining the systematic positions of Mesozoic fossils within these groups can often be challenging. Here we describe and illustrate a puzzling cucujiform beetle, Isocryptophilus exilipunctus Li & Cai gen. & sp. nov., based on an individual from mid-Cretaceous Burmese amber. While we cannot definitively pinpoint the exact phylogenetic position of Isocryptophilus, its possible affinity to Erotylidae is discussed in light of our phylogenetic analyses. A broader-sampled morphological matrix, coupled with a robust molecular phylogeny of these groups, will be promising for clarifying the systematic placement of the fossil.
ABSTRACT
Weevils represent one of the most prolific radiations of beetles and the most diverse group of herbivores on land. The phylogeny of weevils (Curculionoidea) has received extensive attention, and a largely satisfactory framework for their interfamilial relationships has been established. However, a recent phylogenomic study of Curculionoidea based on anchored hybrid enrichment (AHE) data yielded an abnormal placement for the family Belidae (strongly supported as sister to Nemonychidae + Anthribidae). Here we reanalyse the genome-scale AHE data for Curculionoidea using various models of molecular evolution and data filtering methods to mitigate anticipated systematic errors and reduce compositional heterogeneity. When analysed with the infinite mixture model CAT-GTR or using appropriately filtered datasets, Belidae are always recovered as sister to the clade (Attelabidae, (Caridae, (Brentidae, Curculionidae))), which is congruent with studies based on morphology and other sources of molecular data. Although the relationships of the 'higher Curculionidae' remain challenging to resolve, we provide a consistent and robust backbone phylogeny of weevils. Our extensive analyses emphasize the significance of data curation and modelling across-site compositional heterogeneity in phylogenomic studies.
Subject(s)
Coleoptera , Weevils , Animals , Weevils/genetics , Phylogeny , Data Curation , Evolution, MolecularABSTRACT
Ptiliidae (featherwing beetles) is a group of minute staphylinoid beetles with a scarce fossil record. Here a second member of the Mesozoic genus Kekveus Yamamoto et al. is reported from mid-Cretaceous Burmese amber, with detailed morphology obtained through confocal microscopy. Kekveus brevisulcatus Li, Yamamoto, Newton & Cai sp. nov. shares with K. jason Yamamoto et al. the unpaired medial pronotal fovea and narrowly separated transverse metacoxae, but can be separated from the latter based on its less elongate body, shorter pronotal foveae, and much weaker transverse depression on the head. Our phylogenetic analyses support the discheramocephalin affinity of Kekveus, although its relationship with other members of Discheramocephalini cannot be confidently resolved.
Subject(s)
Coleoptera , Animals , Amber , Phylogeny , Myanmar , FossilsABSTRACT
The second species of the extinct genus Burmalestes Tomaszewska & lipiski, B. jingruoyaae Li & Cai sp. nov., is reported from mid-Cretaceous Kachin amber of northern Myanmar. The new species shares characters with both Burmalestes (antennomere 5 elongate and procoxae subcontiguous) and Cretaparamecus Tomaszewska et al. (protibiae toothed and pronotum without basolateral sulci), providing valuable information on the morphological variability of this group.
Subject(s)
Coleoptera , Animals , Coleoptera/anatomy & histology , Amber , Fossils , Head/anatomy & histologyABSTRACT
Two new species of the prostomid genus Vetuprostomis Engel Grimaldi (Coleoptera: Tenebrionoidea: Prostomidae), V. angularis Li Cai sp. nov. and V. gaoi Li Cai sp. nov., are described from the mid-Cretaceous Burmese amber. Vetuprostomis is suggested to be more closely related to extant Dryocora Pascoe distributed in Australia and New Zealand, rather than the widespread genus Prostomis Latreille. A key to prostomid genera, as well as species in genus Vetuprostomis, is provided.
Subject(s)
Amber , Coleoptera , Animals , Fossils , MyanmarABSTRACT
The fossils once assigned to Raractocetus Kurosawa from the Mesozoic and Cenozoic amber deposits differ from extant Raractocetus in the longer elytra, the more strongly projecting metacoxae, and the hind wing with vein 2A forked. Thus, these fossils should be removed from Raractocetus. Cretoquadratus engeli Chen from Kachin amber appears to be conspecific with R. fossilis Yamamoto. As a result, R. fossilis and R. extinctus Yamamoto from Kachin amber, R. balticus Yamamoto from Baltic amber, and R. sverlilo Nazarenko, Perkovsky & Yamamoto from Rovno amber are transferred to Cretoquadratus Chen, as C. fossilis (Yamamoto) comb. nov., C. extinctus (Yamamoto) comb. nov., C. balticus (Yamamoto) comb. nov., and C. sverlilo (Nazarenko, Perkovsky & Yamamoto) comb. nov., and C. engeli syn. nov. is suggested to be a junior synonym of C. fossilis.
ABSTRACT
As one of the earliest-diverging lineage of the megadiverse beetle suborder Polyphaga, marsh beetles (Scirtidae) are crucial for reconstructing the ancestor of all polyphagan beetles and the ecomorphological underpinnings of their remarkable evolutionary success. The phylogeny of marsh beetles has nonetheless remained challenging to infer, not least because of their fragmentary Mesozoic fossil record. Here we describe a new scirtid beetle genus and species, Varcalium lawrencei gen. et sp. nov., preserving internal tissue, from Albian-Cenomanian Kachin amber (ca 99 Ma), representing the second member of this family known from the deposit. Based on a formal morphological phylogenetic analysis, Varcalium is recovered within the crown-group of Scirtinae, forming a clade with other genera that possess subocular carinae. The finding suggests that the crown-group of Scirtinae has already diversified by the mid-Cretaceous.
Subject(s)
Amber , Coleoptera , Animals , Coleoptera/anatomy & histology , Fossils , Myanmar , Phylogeny , WetlandsABSTRACT
A new fossil genus and species of Cantharidae, Nothotytthonyxserratus Li, Biffi, Kundrata & Cai gen. et sp. nov., is reported from mid-Cretaceous Burmese amber. The new species is tentatively attributed to the extant subfamily Malthininae based on a combination of characters, including the symmetrical apical maxillary palpomeres, shortened elytra, pronotum with arched margins and well-defined borders, tibiae with apical spurs, and tarsal claws simple, although its well-developed gonostyli are atypical in Malthininae. The discovery of Nothotytthonyx also suggests a possible Gondwanan origin for Malthininae.
ABSTRACT
A new species, Vetubrachypsectra huchengi Li, Kundrata & Cai sp. nov., is described from mid-Cretaceous Burmese amber on the basis of a single adult female. The species is assigned to genus Vetubrachypsectra Qu & Cai based on its serrate antennae, long maxillary palps, presence of tibial spurs, and elytra without clear striae. Vetubrachypsectra huchengi differs distinctly from V. burmitica Qu & Cai, the only other species in the genus, in having the pedicel apically attached to the scape. Some other differences between the female of V. huchengi and the male of V. burmitica include less serrate antennae, a broader pronotal disc, a broader scutellar shield and smaller tibial spurs. However, at least some of these characters can be considered sexually dimorphic.
ABSTRACT
A new genus and species of the cleroid family Lophocateridae are described and illustrated from the mid-Cretaceous amber of northern Myanmar. Gracilenticrus burmiticus Yu, Kolibác & Slipinski gen. et sp. nov. is unique among Lophocateridae in the tiny body size, frontoclypeal suture and antennal grooves absent, symmetrical antennal clubs, protrochantin reduced, tarsal claws small and widened at base. A key to the species of Mesozoic Lophocateridae is also provided. Morphological characters of the newly discovered Gracilenticrus were analyzed together with representatives of 43 extant genera of Cleroidea (broadly defined Trogossitidae) in a matrix of 91 characters. Gracilenticrus burmiticus was resolved as a member of Lophocateridae. The discovery of a diverse fauna of Lophocateridae in the mid-Cretaceous sheds a new light on the early evolution of superfamily Cleroidea.
ABSTRACT
We here report a new elateroid, Anoeuma lawrencei Li, Kundrata and Cai gen. et sp. nov., from mid-Cretaceous Burmese amber. Though superficially similar to some soft-bodied archostematans, Anoeuma could be firmly placed in the polyphagan superfamily Elateroidea based on the hind wing venation. Detailed morphological comparisons between extant elateroids and the Cretaceous fossils suggest that the unique character combination does not fit with confidence into any existing soft-bodied elateroid group, although some characters indicate possible relationships between Anoeuma and Omalisinae. Our discovery of this new lineage further demonstrates the past diversity and morphological disparity of soft-bodied elateroids.
ABSTRACT
The morphology of the Jurassic fossil Archaeolus funestus Lin, 1986, which was previously placed in the extinct click-beetle subfamily Protagrypninae (Coleoptera: Elateridae), is revised based on a re-examination of the type specimen. The validity of Protagrypninae is discussed and further questioned, partly based on the newly observed characters in A. funestus, including the surface sculpture of the mesoventrite. A possible Throscidae affinity of monotypic Archaeolus Lin, 1986, as suggested in a recent study, is further critically reviewed.
ABSTRACT
A new lycid beetle, Murcybolus longiantennus gen. et sp. nov., is reported from mid-Cretaceous Burmese amber (ca. 99 Ma). Murcybolus is placed in the recently erected fossil tribe Burmolycini based on the fully metamorphosed female, 10-segmented antennae, and pronotal disc with deep rounded punctures but without carinae. Murcybolus differs from the other genus in Burmolycini, Burmolycus, by its antennal morphology and elytral venation.
Subject(s)
Amber , Coleoptera/classification , Animals , Female , Fossils , MyanmarABSTRACT
Captopus depressiceps gen. et sp. nov., Electrothroscus yanpingae gen. et sp. nov. and Pseudopactopus robustus gen. et sp. nov. are reported from the mid-Cretaceous Burmese amber. These new findings greatly extend the Mesozoic diversity of Throscidae, which implies a high degree of morphological disparity for this family in the Cretaceous.
