Extinct Genus Research Articles

A revision and addition to Zopheridae (Coleoptera: Tenebrionoidea) in Baltic amber: possible connections between modern Holarctic distributions and Eocene ‘amber forests’

One new extinct genus and six new extinct species of Zopheridae are described and illustrated from Eocene Baltic amber: Usechus andrushchenkoi Alekseev et Bukejs sp. nov., Coxelus carstengroehni Alekseev et Bukejs sp. nov., Paha vanivanitatum Alekseev et Bukejs sp. nov., Lasconotus tenebrisilvarum Alekseev et Bukejs sp. nov., Helioctamenus groehni Alekseev et Bukejs sp. nov., and Thanatoplagia tamutisi Alekseev et Bukejs gen. et sp. nov. These described taxa include the first fossil representatives of five extant genera and two extant tribes of the family Zopheridae. The assumed paleoecology of these taxa within the amber-producing forest paleohabitat, as well as zoogeography of new fossils are discussed. In addition, new fossil records of Xylolaemus legalovi Alekseev et Bukejs, 2016, X. richardklebsi Alekseev et Bukejs, 2016, Endophloeus gorskii Alekseev et Bukejs, 2016, Yantaroxenos colydioides Nabozhenko, Kirejtshuk et Merkl, 2016, and Zopheromimus auriborussiensis Alekseev et Nabozhenko, 2023 from Baltic amber are presented. A catalogue of Zopheridae described from Baltic amber (currently 19 species within 16 genera) is compiled herein, and an identification key for all taxa is provided. The zoogeographical affinities of the Baltic amber zopherid assemblage are assessed. The present-day disjunct distributions of the zopherid genera that have survived since the Eocene and are currently present in the Holarctic region probably resulted from a uniform fauna in the warm temperate regions of the Northern Hemisphere in the first half of the Paleogene. This uniform fauna was followed by independent reduction of distributions within four regions (West Palearctic, East Palearctic, West Nearctic, and East Nearctic). The ‘circum-Arctic quadrants’ schema is proposed for visualisation of this hypothesis. Additionally, a zonal middle to late Eocene ‘amberiferous ring’ is hypothesized as a probable migration pathway for several zopherids in this part of the Eocene. This ‘ring’ is a belt of amber-producing forests in the Northern Hemisphere, with the potential to preserve a wider distribution of taxa that relied on mixed conifer-fagacean forests similar to the Baltic amber forest flora and its faunal assemblage.

First fossil evidence of an extinct malvalean genus from India

ABSTRACT Hither, an extinct floral element of Florissantia Knowlton, unearthed from the early Eocene (~55–52 Ma) of the Gurha lignite mine, Rajasthan, western India, aids in highlighting the evolutionary significance of this angiosperm lineage in the Indian Cenozoic history. Comparison with fossil taxa from other regions supports the attribution to an extinct malvalean genus Florissantia. It is characterized by a transversely impressed, actinomorphic, gamosepalous flower with five rounded lobed sepals, each sepal fused at least 60% of its length, sinuses between sepal lobes shallowly incised and radiating reticulate venation. The occurrence of this extinct genus, previously known only from the Paleogene of North America and East Asia, is pertinent to the malvalean floristic diversification in India.

Evolution and mandibular sexual dimorphism in mid‐Cretaceous scorpionflies (Insecta: Mecoptera: Meropeidae)

AbstractBased on several earwigfly specimens with well‐preserved mouthparts of Meropeidae from mid‐Cretaceous Burmese amber, a detailed, initial analysis was conducted of the structure of Mesozoic meropeids. Compared to the singularly flattened mandible of modern meropeids, the new specimens reveal that Mesozoic representatives had two distinct types of mandibles: blade‐shaped and scoop‐shaped. Current fossil evidence indicates that during the Mesozoic Era, Meropeidae displayed sexual dimorphism that was reflected in the structure of their mandibles. This structural difference may indicate that about 99 million years ago, meropeids had a more complex diet than extant confamilial taxa. Phylogenetic results suggest that Torvimerope gen. nov., along with Burmomerope, two extinct genera, form a clade and that are the sister taxon to crown‐group Meropeidae. The new material offers new possibilities for inferring the feeding habits and mating behavior of early Meropeidae.

Cretaceous and Paleocene fossils reveal an extinct higher clade within Cornales, the dogwood order.

Characterization and phylogenetic integration of fossil angiosperms with uncertain affinities is relatively limited, which may obscure the diversity of extinct higher taxa in the flowering plant tree of life. The order Cornales contains a diversity of extinct taxa with uncertain familial affinities that make it an ideal group for studying turnover in angiosperms. Here, we describe a new extinct genus of Cornales unassignable to an extant family and conduct a series of phylogenetic analyses to reconstruct relationships of fossils across the order. Two permineralized endocarps were collected from the Cedar District Formation (Campanian, 82-80 Ma) of Sucia Island, State of Washington, United States. Fossils were sectioned with the cellulose acetate peel technique and incorporated into a morphological dataset. To assess the utility of this dataset to accurately place taxa in their respective clades, we used a series of phylogenetic pseudofossilization analyses. We then conducted a total-evidence analysis and a scaffold-based approach to determine relationships of fossils. Based on their unique combination of characters, the fossils represent a new genus, Fenestracarpa washingtonensis gen. nov. et sp. nov. Pseudofossilization analyses indicate that our morphological dataset can be used to accurately recover taxa at the major clade to family level, generally with moderate to high support. The total-evidence and scaffold-based analyses recovered Fenestracarpa and other fossil genera in an entirely extinct clade within Cornales. Our findings increase the reported diversity of extinct Cornales and indicate that the order's initial radiation likely included the divergence of an extinct higher clade that endured the end-Cretaceous Mass extinction but perished during the Cenozoic.

Hop, walk or bound? Limb proportions in kangaroos and the probable locomotion of the extinct genus Protemnodon

Kangaroos (Macropodoidea) display a diversity of locomotor modes, from bounding quadrupedally to hopping bipedally; but hopping has a body mass limit, which was exceeded by a number of extinct taxa. In the Pleistocene, a variety of “giant” kangaroos existed, both within the extinct subfamily Sthenurinae and the extant subfamily Macropodinae (both within the family Macropodidae). Sthenurines have been previously considered to have a type of locomotion (bipedal striding) different from extant kangaroos, but the primary locomotor mode of the large species of the extinct “giant” macropodine genus Protemnodon, closely related to extant large kangaroos, has undergone little question and has been assumed to be hopping. Here, the association between limb proportions and locomotor mode across Macropodoidea is assessed by examination of functional limb indices. We show that large (> 100 kg) Protemnodon species are unlike any other known macropodoids; their position in this functional morphospace, along with previously published evidence on humeral morphology, supports a prior hypothesis of a primarily quadrupedal mode of locomotion, likely some sort of bounding.

Re-investigation of the Mesozoic cycad genus Chilinia: Fossil record, diversity, spatio-temporal distribution, and palaeoclimate implications

Chilinia is an extinct genus of cycads, established by Li and Ye in 1964 based on leaf fossils from the Lower Cretaceous in Jilin Province, China. Morphologically, the genus Chilinia closely resembles Ctenis, another cycad foliage genus, in having pinnately divided leaves with laterally inserted pinnae on the rachis and reticulate venation but differs mainly from the latter in having toothed or irregularly lobed rather than entire-margined pinnae. Fossil records show that up to now, nine species of Chilinia have been reported worldwide, representing an index fossil plant in the Jurassic to Early Cretaceous. In this study, we present a comprehensive overview of all reported Chilinia fossils from a systematic palaeobotanical perspective. Fossil records indicate that Chilinia mainly occurred in the middle–high latitudes of the northern and southern hemispheres in Pangea from the Middle Jurassic to Middle Cretaceous. Combined evidence from the morphology of Chilinia and its floral patterns suggests that the genus probably lived in humid warm-temperate palaeoclimatic conditions with brief seasonal variations.

Unveiling ancient diversity of long-tailed wasps (Hymenoptera: Megalyridae): new taxa from Cretaceous Kachin and Taimyr ambers and their phylogenetic affinities

The Megalyridae are a small family of parasitoid wasps comprising eight extant genera (71 species) and six extinct genera (13 species). Here, we report eight new species from Late Cretaceous Kachin (Myanmar) and Taimyr (Russia) ambers; the family is recorded for the first time from the latter. †Cretolyra noijebumensisgen. et sp. nov., †Cretolyra shawigen. et sp. nov., †Genkyhag innebulagen. et sp. nov., †Megacoxa chandrahrasagen. et sp. nov., †Megacoxa janzenigen. et sp. nov., and †Megacoxa synchrotrongen. et sp. nov., are described from late Albian – early Cenomanian Kachin amber; †Kamyristi exfrigoregen. et sp. nov. and †Kamyristi yantardakhensisgen. et sp. nov. from Taimyr amber (Baikura, late Albian – early Cenomanian Ognevka Formation and Yantardakh, Santonian Kheta Formation, respectively). Phylogenetic analyses of the family are presented and the classification of the Megalyridae is revised accordingly. A new tribe, †Megalavinitrib. nov., is erected to accommodate †Cretolyragen. nov., †Genkyhaggen. nov., †Megacoxagen. nov. together with †Megalava Perrichot, 2009; †Megalavinitrib. nov. is characterized by the vein M fully pigmented and veins Rs+M and M+Cu aligned, the crenulate mesometapectal sulcus, and the pronotal spiracle not posteriorly surrounded by cuticle. This spiracular condition was previously only observed in †Megazar Perrichot, 2009, thus the subfamily †Megazarinae Perrichot, 2009 stat. nov. is proposed for the clade (†Megalavini + †Megazar), as sister to the remaining Megalyridae. The latter is defined as the Megalyrinae, with †Kamyristigen. nov. being retrieved as sister to all other genera except Rigel Shaw, 1987 under parsimony analyses. To align phylogeny with classification, three new tribes are erected (†Kamyristinitrib. nov., †Megallicinitrib. nov., and †Valaainitrib. nov.) and the †Cretodinapsini is synonymized under Megalyrini. A grouping [Rigel + Megalyridia] is supported under Bayesian analyses, which is the only specific conflict with the parsimony analyses, suggesting some degree of caution with respect to the internal relationships of the Megalyrinae. Finally, a revised key to the Megalyridae genera is provided.

Another one bites the dust: A new Lithoserix species (Hymenoptera, Ichneumonidae, Pimplinae) from the early Oligocene in France, with an evaluation of wing morphometrics

A new Darwin wasp species, Lithoserix oublierisp. nov. is described and illustrated from the early Oligocene limestone formation Calcaires de Campagne-Calavon in the Luberon Region, France. It represents the third species of this extinct genus, which was first described from the late Eocene Florissant Formation in Colorado, US and later found in Aix-en-Provence, France, from the late Oligocene. The taxonomic placement of this genus in the context of tribal classification is analysed and discussed, based on geometric morphometrics of the fore and hind wing venation of fossil and extant Pimplinae species. The results suggest that Lithoserix does not belong to the same group as the extinct genus Crusopimpla, but rather represents a more basal genus within Pimplini or belongs to an extinct separate tribe, closely related to Pimplini.

The origin of the Malesian fossil turtle diversity: Fossil versus molecular data

The origin of the turtle fauna of Malesia is analysed here through a review of the literature, a re-evaluation of previously described material, and the description of new material. Very few data are available prior to the Quaternary. While the Early Pleistocene record is largely dominated by reports of giant tortoises, the Middle Pleistocene record provides reports of the first occurrences of most extant taxa living in the area. Most, if not all, of the faunas have stronger relationships with Indochinese than with East Asian taxa, suggesting that colonisation largely followed the Siva- or Sino-Malayan routes, allowing turtles to invade the Sunda Shelf and disperse further east during periods of low sea-level. On the other hand, there is nearly no fossil data to understand the origin of the six endemic Malesian species, but molecular studies suggest that most of these taxa may have evolved in Malesia well before the Quaternary dispersal of the Indochinese fauna. In addition to clarify several fossil identifications, we provide evidence that the box turtle of the ``Cuora amboinensis'' species complex arrived in the Philippines before the early Middle Pleistocene. We also confirm that Duboisemys isoclina is an endemic extinct genus and we discuss its relationship to continental and endemic turtles.

New material of Euroleptochromus tuberculatus Yin & Cai (Coleoptera: Staphylinidae: Scydmaeninae) in Eocene Baltic amber.

The extinct members of the ant-like stone beetle supertribe Mastigitae are among the best studied groups of all fossil Scydmaeninae, and their evolutionary history can be traced from the latest Albian to the earliest Cenomanian through Miocene/Oligocene, with seven extinct genera being described (summarized in Jaoszyski, 2016; Jaoszyski & Perkovsky, 2016; Jaoszyski et al., 2018; Ross, 20192022 (list of Burmese amber taxa)).

A new species of Burmalestes Tomaszewska & lipiski from mid-Cretaceous Kachin amber (Coleoptera: Endomychidae).

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.

A New Extinct Genus of Long-Legged Flies, with a Brief Review and Key to Extinct Genera of Baltic Amber Dolichopodidae (Diptera)

A New Extinct Genus of Long-Legged Flies, with a Brief Review and Key to Extinct Genera of Baltic Amber Dolichopodidae (Diptera)

A new pseudoscorpion genus (Garypinoidea: Garypinidae) from the Eocene supports extinction and range contraction in the European paleobiota.

During the Paleogene, the Holarctic experienced drastic climatic oscillations, including periods of extensive glaciation. These changes had a severe impact on both the flora and fauna causing widespread extinction and range shifts with some taxa retreating to refugia in the Mediterranean Basin. Here we provide evidence for this hypothesis using fossils from the pseudoscorpion family Garypinidae Daday, 1889 (Arachnida: Pseudoscorpiones). This family comprises 21 extant genera from all continents except Antarctica but is restricted to low mid-latitudes (<44°N) in the Northern Hemisphere. We provide the second record of garypinids from the European succinite ambers of the Eocene by describing the first extinct genus in Garypinidae, Baltamblyolpium gen. nov., which includes two species: Baltamblyolpium gizmotum sp. nov. from Baltic amber and Baltamblyolpium grabenhorsti sp. nov. from Bitterfeld amber. The new genus exhibits a morphology that closely resembles Neoamblyolpium Hoff, 1956 from western North America and the genus Amblyolpium Simon, 1898, which is widespread but includes taxa restricted to Mediterranean refugia in Europe. The discovery of a new fossil genus of Garypinidae from Europe confirms that the family was found at more northerly latitudes during the Eocene, however, extinction and range contraction resulted in their present-day relictual distribution in southern Europe like many other lineages that once thrived in the European "Baltic amber forest" of the Eocene.

New insights into the phylogeny of Stephanidae (Hymenoptera: Apocrita), with a revision of the fossil species

The family Stephanidae (Hymenoptera) constitutes a unique group within the Apocrita, playing a pivotal role in the evolution of parasitoid wasps. Although the phylogeny of Stephanidae has been previously inferred, it remains at a low resolution when considering both extinct and extant genera, as well as the enigmatic extinct genus †Electrostephanus. Here, we undertake a revision of Stephanidae extinct, presenting descriptions of new specimens from late Cretaceous Burmese amber and early Eocene Baltic amber. Combining all extant and extinct genera, the phylogeny of Stephanidae was analyzed, incorporating 57 species within 21 genera based on 64 morphological characters. We apply both under maximum parsimony with equal weighting and implied weighting methods, with four species representing early Apocrita as outgroups. Divergence times are estimated by utilizing extinct taxa as calibration points. A new basal subfamily of stephanid wasp, †Lagenostephaninaesubf. nov. was established, encompassing †Lagenostephanus and the newly described genera †Tumidistephanusgen. nov and †Neurastephanusgen. nov. The genus †Electrostephanus is redefined, with two species assigned under distinct genera, †Neurastephanusgen. nov. and †Aphanostephanusgen. nov.. We discuss some of the putative morphological synapomorphies of evolutionary significance within the phylogenetic framework. Our results complement several characteristics of great taxonomic importance for Stephanidae and provide new insights into the early evolution of the family.

A new brown lacewing (Neuroptera: Hemerobiidae) from mid-Cretaceous Myanmar amber

A new genus and species of fossil hemerobiid, Longantenna hei gen. et sp. nov., is described from the mid-Cretaceous Burmese amber. This new genus exhibits the venation characters combination of RP with only one stem and the forewing ScP and RA separated, resembling the extinct genus Hemeroberotha Makarkin &amp; Gröhn, 2020 from the same assemblage, meanwhile it shows more differences from the other Mesozoic and Cenozoic hemerobiid genera. Besides, the ORBs variations among the extinct and extant hemerobiids are discussed.

New larval records of the extinct hard tick Compluriscutula vetulum (Arachnida: Ixodida) from Burmese amber, with notes on its morphology

The hard tick Compluriscutula vetulumPoinar and Buckley, 2008 (Ixodida: Ixodidae) from the mid-Cretaceous (ca. 100 Ma) Burmese amber of Myanmar was first described in a new, extinct genus based on a larva. Here, several more larvae are documented providing additional morphological data based on optical studies using a Keyence VHX-6000 Digital Microscope supplemented by computed microtomography (µ-CT). We confirm the presence of 14 festoons (not 13) on the posterior margin of the body, a character unique for the genus. We further describe an unusual pattern of hypostome dentition in the mouthparts, with an unequal and uneven 2/2 arrangement. Moreover, on the internal side of the palps, to the second and third segments five tooth-like elements are present, similar to the hypostome dentition. Fossil ticks are generally very rare, thus the discovery of numerous new specimens of C. vetulum suggests that it may have been relatively common in the Burmese amber forest. Larval instars predominate in the fossil record and we might speculate that they preferred arboricolous hosts.

Diversity Phenomenon of the Danaceinae Malachite Beetle Subfamily (Coleoptera: Dasytidae) in Eocene Baltic Amber with a New Description of an Extinct Genus and Species

A new malachite beetle, Baltamauroania mirabilicornis gen. et sp. nov., belonging to the tribe Amauroniodini (Coleoptera: Dasytidae) embedded in Eocene Baltic amber is described and illustrated. The new genus differs from the congeners of the tribe Amauroniodini in possessing a black, elongated, and subparallel body and a pronotum with scalloped lateral sides; long and 11-segmented antennae, with three apical antennomeres enlarged and forming a ‘club’ shape, with cylindrical antennomere 1; tarsi shortened and compressed, 5-segmented, with tarsomeres 1 and 2 equal in length, and tarsomere 5 the longest in all legs; pubescence of the dorsal surface consisting of short strong brown semi-erect and fine adpressed setae; punctation of dorsal surface irregular, elytra lacking grooves; pronotum almost equilateral, slightly elongated, with acute anterior and obtuse posterior angles, with wide margination of basal side and with scalloped and finely margined lateral sides; lateral edges of pronotum weakly rounded, with obtuse protuberance before middle. This is the second extinct genus and third record of the subfamily Danaceinae found in Eocene amber. The fossil records of the family Dasytidae are discussed. Three recent records of different Amauroniodini taxa from Eocene East European amber (Baltic and Rovno) show there to have been a high Danaceinae biodiversity in both the southern coast of the Subparatethys (documented by Rovno amber) and in its northern coast (documented by Baltic amber). The phenomenon of Danaceinae diversity in the Eocene Epoch is discussed.

Discovery of a new extinct spider wasp (Hymenoptera, Pompilidae) from Eocene Rovno amber.

Paleogenia waichertae Loktionov, Lelej et Perkovsky, sp. nov. is a new species of extinct spider wasps. This new species is a second record of Pompilidae from Rovno amber, third yet known species of the extinct genus Paleogenia Waichert et Pitts, 2016 and 26th known extinct species of spider wasps. Sex of the holotype of the species Paleogenia indomini Colombo et Waichert, 2023 is clarified (male not female). A key to males of Paleogenia is provided.

Nichima gen. nov. (Alismataceae) based on reproductive structures from the Oligocene-Miocene of Mexico.

Alismataceae, a sub-cosmopolitan 28 family with ca. 17 genera 29 and 113 species, is a large group of aquatic plants. Compression/impressions and bio-inclusions in amber support the documentation of the lineage in low-latitude North America. In Mexico, fossil aquatic plants have been infrequently documented. The new flowers recognize a group mainly known through fruits and seeds. Impression/compression reproductive structures from the Oligocene Los Ahuehuetes locality, Puebla, and bio-inclusions from the Miocene amber of Simojovel de Allende, Chiapas, Mexico, known through 150 samples. They are described and compared with extinct and extant taxa. A parsimony analysis based on 29 floral characters of 17 extant genera of the Alismataceae evaluates the relationship between the fossil material and their potential living relatives. Nichima gen. nov. is a perfect, actinomorphic flower with an expanded receptacle, three persistent sepals with multi-vasculature, delicate and caducous petals, six stamens, and gynoecium composed of three to more superior carpels, maturing into achenes. These characteristics resemble flowers of Alismataceae. Nichima represents an extinct member of the family, with two new species, Nichima magalloniae L. Hern., Cevallos-Ferriz et Hernández-Damián sp. nov. and Nichima gonzalez-medranoi L. Hern., Cevallos-Ferriz et Hernández-Damián, sp. nov. Their phylogenetic position suggests affinity with a clade that includes Baldiella, Echinodorus, and Alisma. Reproductive structures from the Cenozoic of Mexico support the identification of a new extinct genus, Nichima, evidencing Alismataceae's extensive history in North America's low latitudes and suggests a southern extension of the Boreotropical Flora. This article is protected by copyright. All rights reserved.

From Priabonian to Selandian: a new species of Eocenostenus (Coleoptera: Staphylinidae: Steninae) from the Paleocene Menat Formation of France

A new species of the extinct genus Eocenostenus Cai, Clarke, Huang &amp; Nel, 2014, is described from the middle Paleocene (Selandian) of Menat (France). Eocenostenus vanja sp. nov. is the second known species of the genus, the first being Eocenostenus fossilis Cai et al., 2014 described from the late Eocene (Priabonian) of Monteils, France. The discovery of E. vanja has implications for our understanding of the evolution of Eocenostenus because it pushes back the origin of the genus by several tens of millions of years (i.e., from the Priabonian to the Selandian). Additionally, it possibly sheds light on the cuticular colouration of this genus, which is putatively similar to some extant Steninae, particularly those from the tropical regions of the world. An updated checklist of fossil Steninae is provided.